___....¢-"* .nu'” ' 7' ._ ,. ‘ _.. . 7‘ ‘,...‘........ - . 21%33075 1. STATE UNIVERSITY LIBRARIEQ I llllWill”.lll‘filillill lliLili'ili l'llllll‘fl hil 3:283 3 1293 00571 31.97 7 LIBRARY Michigan State University L This is to certify that the thesis entitled Quality evaluation of dry edible beans after soaking, processing and canned storage . presented by Janet G. Wilson has been accepted towards fulfillment of the requirements for M.S. degree in FOOd SCience fliflé/{gg Major professor Date Febgfly 23. 1989 0-7639 MS U is an Aflirmative Action/Equal Opportunity Institution MSU RETURNING MATERIALS: Place in book drop to remove this checkout from LIBRARIES .-;I—. your record. FINES will be charged if book is returned after the date stamped below. . ‘1 g 2 .23 “a 5L “ f 7;? " 1-1 he, ‘ an 53" so \ N 3;) 9') V QUALITY EVALUATION OF DRY EDIBLE BEANS AFTER SOAKING, PROCESSING, AND EXTENDED CANNED STORAGE BY Janet G. Wilson A THESIS Submitted to Michigan State University in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE Department of Food Science and Human Nutrition 1989 ABSTRACT QUALITY EVALUATION OF DRY EDIBLE BEANS AFTER SOAKING, PROCESSING, AND EXTENDED CANNED STORAGE BY Janet G. Wilson Dry beans (2111533115, We L_._) were evaluated for quality in a series of three studies following soaking, processing, and extended storage. Processed bean texture was measured in Study 1 using objective and subjective methods. In Study 2 the amount and rate of water and calcium absorbed during soaking was investigated. Study 3 evaluated. processed bean quality during extended storage. Significant correlations were developed between objective and subjective measures with prediction equations for processed texture. Calcium absorption was greater from soak medium than from brine medium during processing. A heated soak treatment allowed increased calcium absorption, increased firmness and decreased drained weight in processed beans when compared to an unheated soak. During extended storage of processed beans, a decrease in drained weight and an increase in firmness occurs. A heated soak treatment produced more quality changes over time while the unheated soak produced little change. ACKNOWLEDGEMENTS I would like to express my gratitude to Drs. Hosfield, Markakis, and Zabik for their patience and guidance during my graduate studies. This committee has provided a true atmosphere for nurturing students. A very special and heartfelt thanks goes to my advisor, Dr. Mark Uebersax. His encouragement and patience is unending. I am appreciative of all the experiences that he provided for me and the extra time that he gave to help me develop skills for my professional career. I feel privileged to have worked with him and feel he is truly outstanding as a teacher, scientist, leader and a friend. I would also like to thank my fellow students for their cooperation and support during my graduate work at MSU. Special appreciation is extended to Patty Gunn for her continuous enthusiasm and friendship. Many thanks goes to my husband Tim, for cultivating my desire to learn and providing inspiration during my graduate studies. I also express gratitude to my parents for providing me opportunities to grow and learn. iii TABLE OF CONTENTS LIST OF TABLES . . . . . . . . . . . . . . . . . . . viii LIST OF FIGURES . . . . . . . . . . . . . . . . . . . . x LIST OF EQUATIONS . . . . . . . . . . . . . . . . . xiii LIST OF PLATES . . . . . . . . . . . . . . . . . . . . xiv INTRODUCTION . . . . . . . . . . . . . . . . . . . . . 1 LITERATURE REVIEW . . . . . . . . . . . . . . . . . . 3 Seed Composition . . . . . . . . . . . . . . . . . . 3 Seed Coat . . . . . . . . . . . . . . . . . . . . 3 Cotyledon . . . . . . . . . . . . . . . . . . . . 6 Protein Content . . . . . . . . . . . . . . . . . 9 Lipid Content . . . . . . . . . . . . . . . . . . 9 Carbohydrate Content . . . . . . . . . . . . . . 10 Ash and Mineral Content . . . . . . . . . . . . . 11 Bean Soaking and Blanching . . . . . . . . . . . . . 12 Heat Treatment in Soaking . . . . . . . . . . . . 13 Soak Water Additives . . . . . . . . . . . . . . 15 EDTA . . . . . . . . . . . . . . . . . . . . . . 16 Polyphosphates . . . . . . . . . . . . . . . . . 17 Sodium Salts . . . . . . . . . . . . . . . . . . 17 pH . . . . . . . . . . . . . . . . . . . . . . . 19 Minerals . . . . . . . . . . . . . . . . . . . . 20 Cooking and Processing . . . . . . . . . . . . . . . 21 iv Growing and Genetic Effects Storage Effects Soaking, Blanching, and Cooking Effects Scanning Electron Microscopy Effects of Canned Storage on Quality of Processed Beans . . . . . . . Texture Measurement Mechanical Interpreting Force-Deformation Curves Sensory MATERIALS AND METHODS Dry Bean Handling Prior to Processing Harvest and Storage Dry Bean Color Initial Bean Moisture and 100 g Solids Bean Soaking and Canning Soaking for Canning Soaking Can Filling, Brining, and Exhausting Sealing, Thermal Process and Storage Canned Product Evaluation Total Weight, Vacuum, and Headspace Washed Drained Weight and Visual Examination Objective Color and Texture Evaluation Total Solids Moisture, Ash and Calcium Determination Scanning Electron Microscopy (SEM) Sensory Evaluation of Processed Beans v 21 22 24 26 27 29 29 35 36 41 41 41 41 43 43 43 45 46 46 47 47 47 49 51 51 53 53 EXPERIMENTAL Study 1: Objective and Subjective Measurements of Processed Bean Texture Abstract Introduction Materials and Methods Results and Discussion Objective Data Subjective Data Objective and Subjective Correlations Summary Study 2: Water and calcium absorption in soaking with temperature and calcium concentration Abstract Introduction Material and Methods Results and Discussion Water Absorption Effect of Soak CA Level on Water Absorption Effect of Soak Temperature on Calcium Absorption Combined Effect of Soak Calcium and Temperature on Water Absorption Rate of Water Uptake SEM Micrographs of Bean Microstructure Summary Study 3: Effect of Extended Storage on Processed Kidney Beans . . . . . . . . . . . . . . . Abstract Introduction 59 59 59 60 61 64 64 96 114 120 122 122 122 124 125 125 128 128 130 133 136 141 143 143 143 Material and Methods . . . . . . . . . . . . . . 144 Results and Discussion . . . . . . . . . . . . . 146 Summary . . . . . . . . . . . . . . . . . . . . . 160 SUMMARY . . . . . . . . . . . . . . . . . . . . . . . 161 LIST OF REFERENCES . . . . . . . . . . . . . . . . . . 163 vii LIST OF TABLES Tables. 1. 10. 11. 12. Surface color analysis of dry and processed beans: Soaked and brined in four levels of calcium ion Analysis of variance for surface color analysis of processed beans Moisture measurements of dry, soaked and processed beans: Soaked and brined in four levels of calcium ion Analysis of variance for moisture measurements of soaked and processed beans Quality characteristics of dry, soaked, and processed beans: Soaked and brined in four levels of calcium ion Analysis of variance for quality characteristics of soaked and processed beans Texture analysis of processed beans: Soaked and brined in four levels of calcium ion Analysis of variance for processed bean texture Mineral analysis of dry and processed beans: Soaked and brined in four levels of calcium ion . Analysis of variance for mineral analysis of processed beans Pearson correlation coefficients of physical texture measurements . . . . . . . . Mean rank scores of processed beans soaked and brined in four levels of calcium ion viii 65 67 69 71 72 75 77 79 84 86 95 96 13. 14. 15. 16. 17. 18. 19. 20. 21. 22. 23. 24. 25. 26. Panelist means of Quantitative Descriptive Analysis masticatory test: Processed beans were soaked and brined in four levels of calcium ion Analysis of variance for Quantitative Descriptive Analysis masticatory test Panelist means of Quantitative Descriptive Analysis tactile test: Processed beans were soaked and brined in four levels of calcium ion Analysis of variance for Quantitative Descriptive Analysis tactile test Panelist means of Quantitative Descriptive Analysis visual test: Processed beans were soaked and brined in four levels of calcium ion Analysis of variance for Quantitative Descriptive Analysis visual test Pearson correlation coefficients for texture attributes evaluated by QDA Pearson correlation coefficients for objective and subjective measures of texture Stepwise multiple linear regression equations for objective and subjective measures of processed bean texture Percent water absorbed in four soak temperatures and four soak calcium concentrations Simple regression lines for soak treatments Washed drained weights of processed kidney beans soaked by two methods and stored at three temperatures over time Kramer compression force (Kg/1009) of processed kidney beans soaked by two methods and stored at three temperatures over time Kramer shear force (Kg/100g) of processed kidney beans soaked by two methods and stored at three temperatures over time ix 98 99 100 101 102 103 111 115 117 126 135 147 155 157 LIST OF FIGURES Figures. 1. 10. 11. 12. Structure of typical legume seed: A) External view; B) Internal view. Source: Northern, 1958 Diagram of a plant cell wall. Source: Bourne, 1983 Dry bean handling, prior to processing. Source: Wilson, et al., 1986 Bean soaking and canning procedure. Source: Wilson, et al., 1986 Canned product evaluation. Source: Wilson, et al., 1986 Typical Kramer force curve for processed beans Visual scorecard and reference sheet for texture evaluation of cooked beans using Quantitative Descriptive Analysis Masticatory scorecard and reference sheet for texture evaluation of cooked beans using Quantitative Descriptive Analysis Tactile scorecard and reference sheet for texture evaluation of cooked beans using Quantitative Descriptive Analysis Graphical representation of Quantitative Descriptive Analysis results Relationship of been texture and drained weight Typical Kramer force curves of overnight and 30:30 soaks with calcium treatments from O to 150 ppm 42 44 48 50 55 56 57 58 80 82 13. 14. 15. 16. 17. 18. 19. 20. 21a. 21b. 21c. 21d. 22. 23. 24. Effect of calcium in soak water on total measured bean calcium for overnight soaked beans Effect of calcium in brine medium on total measured bean calcium for overnight soaked beans Measured calcium in overnight soaked and processed beans in calcium from O to 150 ppm Effect of calcium in soak water on total measured bean calcium for 30:30 soaked beans Effect of calcium in brine medium on total measured bean calcium for 30:30 soaked beans Measured calcium in 30:30 soaked and processed beans in calcium from O to 150 ppm QDA representation of panelist means for the overnight soak over four calcium treatments QDA representation of panelist means for the 30:30 soak over four calcium treatments QDA representation of panelist means for two soaks and 0 ppm calcium treatment QDA representation of panelist means for two soaks and 50 ppm calcium treatment QDA representation of panelist means for two soaks and 100 ppm calcium treatment QDA representation of panelist means for two soaks and 150 ppm calcium treatment Calcium absorption in the whole bean following-soaking at four temperatures and in four calcium ion concentrations Calcium absorption in the seed coat of the been following soaking at four temperatures and in four calcium ion concentrations Calcium absorption in the cotyledon of the bean following soaking at four temperatures and in four calcium ion concentrations xi 87 88 9O 91 92 94 105 106 107 108 109 110 129 131 132 25. 26. 27. 28. 29. 30. 31. Percent water uptake after 60 minutes of soaking at four temperatures and four calcium ion concentrations Relationship of bean texture and drained weight for overnight soaked beans during extended storage at 50°F Relationship of bean texture and drained weight for overnight soaked beans during extended storage at 70°F Relationship of bean texture and drained weight for overnight soaked beans during extended storage at 90°F Relationship of been texture and drained weight for 30: 30 soaked beans during extended storage at 50°F . . Relationship of bean texture and drained weight for 30: 30 soaked beans during extended storage at 70°F . . Relationship of been texture and drained weight for 30: 30 soaked beans during extended storage at 90°F . xii 134 149 150 151 152 153 154 LIST OF EQUATIONS Calculation of fresh weight equivalent for CaCl needed for water at a specified ppm Ca++ evel percent weight gain percent soaked bean moisture hydration ratio drained weight ratio force required per sample processed bean moisture and percent ash on a dry basis ppm calcium from atomic Equations. 1. total solids required 2. Calculation of 3. Calculation of 4. Calculation of 5. Calculation of 6. Calculation of 7. Calculation of size 8. Calculation of total solids 9. Calculation of 10. Calculation of absorption reading 11. Linear regression equation xiii 43 45 46 46 46 49 51 51 52 52 116 LIST OF PLATES Plates. 1. Navy beans: Top of seed coat (a-d) and bottom of seed coat (9- -h) following soaking at two temperatures and in two calcium concentrations. A & E = 60° C/0 ppm, B & F = 60°C/150 ppm, c a c = 90° C/O. ppm, 0 & H = 900 C/150 ppm . . . . . . . . . 137 Navy beans: Cross section of cotyledon (a-d) following soaking at two temperatures and in two calcium concentrations. A = 60°C/ngm, s = 60°C/150 ppm, c = 90°C/0 ppm, = 0C/150 ppm . . . . . . . . . . . . . . 140 xiv INTRODUCTION Dry edible beans are a staple food as a primary protein source in many lesser developed countries and considered a speciality item in more industrialized nations. Both household users and commercial processors want a product that will produce consistent quality over time. Texture of the final product will be a key attribute in the evaluation of quality. Processed quality of beans is influenced by many factors including growing environment, storage conditions, soak treatments, processing parameters and length of processed storage. Soak water temperature and soak water additives such as calcium ion have shown to produce significant effects on final processed texture. The objective of this study is to help develop consistency in processing, through an understanding of the factors influencing product quality and to provide a method for measuring and interpreting quality. Measuring texture by objective and subjective methods was the goal of Study 1. The test also included variances on soak method and soak water additives to produce and array of textures and study the changes occurring from them. It relationship between instrumental measures and sensory l 2 attributes was defined for further use in evaluating how processing parameters effect product texture. Study 2 was conducted to evaluate the effect of heat treatment and calcium concentration on water and calcium absorption during soaking. Water and calcium absorption in beans have direct influence on final texture and their rates and total amount absorbed can be significantly influenced during soaking. The emphasis here is placed on the effect of heat and calcium concentration in both individual and combined effects on water and calcium absorption. After processing, canned product will continue to undergo quality changes during extended storage as evaluated in Study 3. A bean—brine equilibration may occur over time especially in the presence of calcium or other ions. Calcium ions present in the brine attempt to achieve equilibrium with the bean causing a firming effect. Most research shows a decrease in drained weight over time which may be attributed to solids loss to the brine or a loss of water through calcium binding in the bean during equilibration. LITERATURE REVIEW W The seeds of leguminous plants differ greatly in color, size, shape and seed coat thickness while they all possess similar seed structure comprising a seed coat and embryonic parts. The seed coat or testa is the outermost layer of the seed and serves as a protector of the embryonic structure. Two prominent external anatomical features include the hilum and micropyle and are thought by many to have a role in water absorption. These structures are shown in Figure 1. The hilum is a large oval scar where the seed and stalk were previously joined. The micropyle is a minute opening in the seed coat which served as a junction where the pollen tube entered the valve. The remaining portion of the seed is the embryonic stem tip, the hypocotyl or embryonic stem and the radicle or embryonic root. This portion is responsible for germination and is extremely vulnerable to damage during handling and storage. figed_§gat. The seed coat has an important function in protecting the legume from damage due to water absorption and ndcrobial contamination, especially during harvest and storage. An intact seed coat provides excellent protection from damage, while the presence of any splits or cracks will 3 ' ._. micropyle hilum A. External view Opicolyl L A | Ir ' undiscl- cotyledon B. Internal view Figure 1. Structure of typical legume seed: A) External view; B) Internal View. Source: Northern, 1958. 5 allow rapid entry of moisture and microorganisms developing a poor quality seed for later planting or food use. The seed coat consists of 7.7% of the total dry weight in the mature bean (Phaseglus_ynlgaris_L+) reported by Powrie et al. (1960) with a protein content of 5% (d.b.). This protein content is consistent with earlier findings of 4.8% protein by Ott and Ball (1943). The major components in the seed coat structure of legumes include the waxy cuticle layer, the palisade cell layer, the hourglass cells and the thick cell-walled parenchyma. These structures have been identified using scanning electron microscopy (SEM) in soybeans (Thorne, 1981), cowpeas (Sefa-Dedeh and Stanley, 1979a), faba beans (McEwen et al., 1974) white beans, pinto beans and adzuki beans (Sefa-Dedeh and Stanley, 1979c). The waxy cuticle layer is the outermost portion of the seed coat and its prime function is to prevent water penetration using its hydrophobic layers of waxy barriers. The cuticle does allow permeation of some polar and non-polar compounds but its main function is in the prevention of water penetration (Bukovac et al., 1981). The palisade layer has been reported by many researchers to appear with a linear lucida, or light line that gives the appearance of two layers of cells (Hamly, 1932; Corner, 1951). White and pinto beans have been found to have a light line (Sefa-Dedeh and Stanley 1979c) with the first cell layer being closest to the cuticle and highly organized while the second layer appears 6 amorphous. Other researchers believe the light line is only an optical effect (Corner, 1951), or simple refraction (Chowdhury and Buth, 1970). Some have found the light line to be completely absent suggesting it may only be present in the seed coat of selected legumes. The cell layers immediately beneath the palisade layer are termed hour glass cells (Corner, 1951). Sefa-Dedeh and Stanley (1979c) described this layer as the amorphous second layer in the palisade layer. The parenchyma layer cells have thick walls and stand out readily after hydration as they appear spongy and show noticeable swelling. The role of the seed coat appears to have some effect on. water absorption however the exact mechanism is not known. Research on soybeans has shown the water absorption rate to be dependent upon calcium content, seed coat surface, micropyle structure, and initial moisture content (Saio, 1976; Men, 1983). In studying the structural components, Sefa-Dedeh and Stanley (1979b) found seed coat thickness, seed volume, and hilum size along with protein content to all be factors in water uptake. This work demonstrated that thinner seed coats absorb water more rapidly during initial soaking (0-6 hrs). Cotyledon. The cotyledon comprises the greatest portion of the bean in terms of weight and volume and contributes a valuable component to the texture and nutritive value of the bean as a food stuff. The cotyledon portion which is responsible for the embryonic leaf tissue 7 in germination makes up 90.5% of the total bean on a dry weight basis (Powrie et al., 1960). They also reported that dry cotyledons contain 39.3% starch, 27.5% protein, 1.65% lipids and 3.5% ash. Processed texture and nutrient availability of beans are influenced by the dimensions and arrangement of the cotyledon cells. The outermost cells are identified as an epidermal layer with an inner and outer portion. The inner cells appear elongated and the outer cell layer as cubical. The epidermal layer is presumed to contain no starch as all cells appear granular which is characteristic of protein. The next apparent layer is the hypodermis which has larger elliptically shaped cells that also appear granular, characteristic of protein makeup. The remaining and largest portion. of the cotyledon contains parenchyma cells bound by a distinct cell wall and middle lamella with a few vascular bundles. The parenchyma cells have thick walls that give rigidity to the cotyledon. Within each parenchyma cell, starch granules are imbedded in a protein matrix. The secondary walls, found only in mature parenchyma cells are very thick and contain. pits which facilitate the diffusion of water during soaking. Figure 2 shows a diagram of a plant cell wall. The intercellular space between primary walls of two cells is termed the middle lamella. The middle lamella is composed mainly of pectic substances and acts to hold cells together while giving strength to the total tissue. Pectic substances n I Microfibrils l i : (organized phase) " ' I Continuous Matrix | | ' (amorphous phase) | l‘L I l < .1 .1 .J --' a g a f. >- E E a < 2 m < D 3 .4 z z ...I c: -— C3 0 m U —- Q U z m I 1 | Cellulose : I ' I i I I Heqicellulose : I l I I l I . I I... i lPect‘Ic substances, I Lignin ! 1'L I Figure 2. Diagram of a plant cell wall. Source: Bourne, 1983. 9 allow cross linking with divalent cations and significantly affect the texture of the plant tissue (Van Buren, 1979). Mattson (1946) and Muller (1967) report that softening occurs in the cell wall during cooking from a reaction of phytate with insoluble Ca/Mg pectate to form soluble Na/K pectate. PW. Legumes are excellent sources of plant protein and range from 20 to 40 percent on a dry weight basis. Researchers of dry beans (Phaseglns_xnlgarifi LL) have reported the protein content to fall in the range of 18.8% to 29.3% (Meiners, et al., 1976a; Varriano-Marston and DeOmana, 1979; Hosfield and Uebersax, 1980). Legume proteins make an important contribution to the diet especially in lesser developed countries. Legumes are found to have a deficiency in protein quality limited by methionine but supply an excess of lysine which is typically a limiting amino acid in cereal grains. Eating legumes and cereals together such as beans and tortillias, results in amino acid completion and increased protein quality for the diet. Total utilization of the legume protein is relatively low. Protein digestibility may be impaired possibly by the presence of tannins (Bressani et al., 1982; Aw and Swanson, 1985) or numerous antinutritional compounds which must be removed or destroyed by heating. W. Legumes vary greatly in their lipid content with the total quantity extractable in organic solvents ranging from 1 to 50 percent. Pulses, possessing 10 predominate carbohydrate reserves, have lower levels of lipid while oilseed legumes possess high lipid reserves. The major fraction of lipid found in legumes is of concern during storage as lipid oxidation can produce off flavors and odors. carbohydra;e__ggntgnt. Legumes contain 24% (winged beans) to 68% (cowpeas) total carbohydrate on a dry basis of which starch is the major fraction accounting for 24 to 56% (Reddy et al., 1984). Total soluble sugars comprised of mono- and oligosaccharides are only a small portion of the total carbohydrate content in legumes. Within the total sugars, the oligosaccharides of the raffinose family are most prevalent ranging from 31 to 76% (Rockland et al., 1979; Reddy and Salunkhe, 1980; Fleming, 1981; Sathe and Salunkhe, 1981). The oligosaccharides found include raffinose, stachyose, verbascose, and ajugose with stachyose being predominate in most varieties of Phaseglus yulgaris L. It is reported that legumes are a good source of crude fiber ranging from 1.2 to 13.5% (Reddy et al., 1984). Cellulose is the major fraction followed by hemicellulose, lignin, pectic and cutin substances. The starch found in legumes has oblong granules which vary in size by species. Research has shown that the legume starch granule is resistant to swelling and rupture and generally contains 20 to 30% amylose content (Naivikul and D’Appolonia, 1979). Starch granules can greatly influence the cooking characteristics of legumes. Gelatinization ll temperatures ranging from 60°C to over 75°C are relatively high compared to cereals and may contribute to processing variability (Hahn et al., 1977). A§h_and_uineral§_ggntgnt. Total ash content of legumes on a dry weight basis is in the range of 2.9 to 4.9% (Watt and Merrill, 1963; Fordham et al., 1975; Meiners et al., 1976; Tobin and Carpenter, 1978; Koehler and Burke, 1981). Ash content is found to decrease after cooking due to leaching with reported losses ranging from 10 to 70% (Watt and Merrill, 1963; Meiners et al., 1976). This wide range of losses could be due to different soaking and cooking methods. Raw beans also demonstrate differences in percent ash with factors such as variety, growing location, and soil composition contributing to the variance. A review of current literature for Phaseglna yglggrifi L. in the raw mature state, indicated that the following ranges for mineral content have been reported in parts per million concentration: Ca, 595-2600; Cu, 5-14; Fe, 13- 135; Mg, 1230-2300; Mn 6-232; Na, 17-210; P, 2800-5700; Zn, 17-65; K, 8208-19400, (Watt and Merrill, 1963; Walker and Hymowitz, 1972; Fordham et al., 1975; Meiners et al., 1976b; Augustin et al., 1981; Koehler and Burke, 1981). Variability may be attributed to bean varieties, growing location, soil composition, and method of measurement. Mineral retention during cooking has been studied. Meiners et al. (1976b) cooked ten legume varieties until tender and measured the contents of nine minerals in the raw 12 and cooked state. Minerals in the cooked legumes were one third to one half the values in the raw legumes. High levels of magnesium, phosphorus, and potassium were found in the cook water. Augustin et al. (1981) found retention of minerals during cooking was 80 to 90% with exception of 38.5% sodium retention and total calcium retention. Koehler and Burke (1981) in a similar study found close agreement with Augustin et al. (1981). BEAN_SQAKING_AND_BLANCHING Research shows that soaking dry beans before cooking can provide many beneficial attributes to the final cooked product. Soaking serves to remove foreign material, facilitate cleaning of beans, aid in can filling through uniform expansion, ensure product tenderness and improve color (Cain, 1950; Crafts, 1944; Hoff and Nelson, 1966). Several methods of soaking have been proposed to accelerate water uptake during soaking thus decreasing the cook time required to tenderize the bean. Various soak methods or pretreatments include: 1) heat treatments (Gloyer, 1921; Dawson et al., 1952; Morris, et al., 1950; Snyder, 1936); 2) soak water additives (Greenwood, 1935; Morris et al., 1950; Reeve, 1947; Elbert, 1961; Rockland, 1963; Snyder, 1936); 3) vacuumization or sonification (Hoff and Nelson, 1967); 4) scarification of seed coat (Morris et al., 1950), and 5) dipping in concentrated sulfuric acid (Gloyer, 1921). The results of these soak treatments provide a wide range of variability in quality attributes of cooked beans. 13 Regardless of treatment, research has demonstrated that there are many physiochemical factors that contribute to the water absorption rate during soaking. Some factors include seed coat thickness, availability of possible paths (the hilum, micropyle, and raphe) of water entry (Kyle and Randall, 1963; Saio, 1976; Sefa-Dedeh and Stanley, 1979c; Korban et al., 1981) pectic substances, storage temperature and humidity, age of bean, initial moisture content, protein content, seed density and bean size. WM- Dry beans have traditionally been soaked overnight (12-14 hours) at ambient temperature prior to commercial processing. To increase the efficiency' of water ‘uptake and. possibly improve quality aspects of the finished product, a heated blanch has been found by many researchers to be effective. Shorter soak times of dry beans for processing show beneficial effects on drained weight and riboflavin retention producing equal or improved quality than that attained in overnight soaking (Nordstrom and Sistrunk, 1977). Junek et al. (1980) found different soak temperatures to have no effect on drained weight of navy beans but kidney and pinto beans had greatest drained weight when soaked at 25°C and 35°C compared to 15°C. Kidney and pinto beans showed increased splitting and decreased firmness when soaked at 35°C. Navy beans split more at 15°C but were softest when soaked at 35°C. Soaking at higher temperatures improved color of kidney and pinto beans with negligible 14 effects on the color of navy beans. Kon (1979) found that increasing the temperature of soak water yielded elevated rates of water uptake and shorter soak times to attain maximum imbibition. Hoff and Nelson (1966) while using soak temperatures from 50 to 90°C established the range for maximum uptake from 60 to 80°C. They attribute the rate of water uptake to the trapped or adsorbed gases in interstitial tissues being released from the bean surfaces by steam pressure, vacuum and sonic energy. Other researchers believe that heat is needed to precipitate the Ca++ and Mg++ ions to prevent tough pectin metal complexes from forming (Mattson, 1946). Another opinion lies with heat causing an inactivation of phytase and pectin esterase (Morris and Seifert, 1961). If these enzymes are allowed to act they could cause a shift in divalent ions and cause tough pectin-metal complexes. VanBuren (1980) measured the amount of calcium binding sites in snap beans inherently and after a 71 and 93°C blanch. The 71°C blanch had more binding sites and created a firmer texture in the presence of calcium added soak medium. More recent work shows that heating effects vegetable texture by causing cell separation and softening from the thermal degradation of intercellular and. cohesive :materials (Bourne 1976; Loh. et al., 1982). During heating the native protopectin forms pectin and will depolymerize rapidly while heated. Steam blanching of dry beans produces a higher drained weight and firmer texture than that attained when water 15 blanching is employed. This depends upon the cultivars used (Sevilla and Luh, 1974; Davis, 1976; Nordstrom and Sistrunk, 1977; Nordstrom and Sistrunk 1979; Drake and Kinman, 1984). Steam blanched beans had more nutrient retention and less leaching of soluble solids than did water blanched beans (Nordstrom and Sistrunk 1979; Sevilla and Luh, 1974). Blanch method as observed by Nerdstrom and Sistrunk (1979) did not effect percent splits but bean type and storage time had a significant effect. Davis et al. (1980) determined that steam blanching produced an equivalent product to water blanching with no significant differences in quality. Beans blanched in steam, when evaluated by judges, were rated higher in color, liquor viscosity, bean wholeness and general appearance. The steam blanch may aid in setting color' and produce gelatinization of starch. with minimum leaching (Nordstrom and Sistrunk, 1979). Although there are many benefits of presoaking, Quast and DaSilva (1977b) found that hydration prior to cooking did not produce significantly different values for cook time. Hsu (1983) in developing a model for maximum water uptake found temperature, solute concentration, and initial moisture content were most important while protein content, density, and bean size had little effect on rate of water uptake. figgk__fla;g;__anfiitiygs. The tOpic of soak water additives and their effect on the rate of water uptake has been a primary area of emphasis by many researchers. Additives of interest include: sodium chloride, sodium l6 tripolyphosphate, sodium bicarbonate (Greenwood et al., 1935), sodium carbonate (Rockland and Metzler, 1967; Varriano-Martson and DeOmana, 1979), hexametaphosphate, malic acid and citric acid (Luh et al., 1975, Junek et al., 1980), ethylene diamine tetra acetic acid (EDTA) (Daoud et al., 1977; Kilgore and Sistrunk, 1981; Lu, et al., 1984), calcium chloride (Luh et al., 1975; Van Buren et al., 1984). EDTA. Hoff and Nelson (1966) observed no effect of EDTA on water uptake. These results concur with data of Junek et al., (1980) where they found no difference in firmness of beans soaked in EDTA. Hewever, EDTA has been found to prevent discoloration in foods due to its’ ability to chelate metal ions and thus reduce their reactivity. Luh et al. (1975) reported EDTA effective in improving color of processed beans which may be attributed to the binding of iron or copper ions with EDTA Naz. Soaking in EDTA produced no firming effects and rendered only a slight improvement in color for Lu et a1. (1984). In nutritional studies on the effects of additives, EDTA was established not to have a detrimental effect on vitamin B6 as did NaHSO3 (Daoud, et al., 1977). Further nutritional studies suggested that EDTA has no effecton the B-vitamins, pantothenate, niacin and folacin (Kilgore and Sistrunk, 1981). As expected, EDTA alone had no effect on shear value and produced improved color values. However, when EDTA was used in combination with bicarbonate buffer, Kilgore and Sistrunk (1981) reported no improvement in color and a firming effect. EDTA 17 when used with phosphate or citrate had a softening effect. Eglyphgsnhgtes. In the investigation of water uptake, a correlation has been observed between tough beans and slow water uptake (Morris, 1963). Metal ions and pectins have obvious influences over bean tenderness as does protein and free fatty acids. Research on frozen fish has shown that small amounts of free fatty acids reduce the water holding capacity of proteins. Polyphosphates are used in the meat industry to increase water holding capacity and they also sequester divalent metal ions so they are especially beneficial in bean soaking. Addition of salts to the soak water will allow the proteins to become more soluble and facilitate ‘water uptake and softening (Hoff and Nelson, 1965). When Hoff and Nelson (1965) did preliminary testing with the addition of polyphosphate and sodium chloride they found an increased amount of water uptake with the polyphosphate and a slightly depressed amount with the sodium chloride. They however, still found greater water uptake with the addition of polyphosphate or sodium chloride than with the conventional soak. Soaking with increased levels of polyphosphate (.5%), the seed coats were so tender they could not be handled without destruction. The optimum finished bean volume and tenderness was obtained by a combination of the additives (Hoff and Nelson, 1965). We. The addition of sodium salts to soak water has been found beneficial in increasing water uptake by many researchers. It is suggested that the sodium salts 18 enhance solubilization of pectic substances due to an ion exchange where the sodium ions replace the toughening divalent ions. In 1936, Snyder reported that the addition of sodium bicarbonate to soften seed coats and cotyledons of beans, had no adverse effect to appearance or flavor. Other research (Dawson et al., 1952) supports the addition of sodium bicarbonate to enhance water uptake. These researchers reported a 42% increase in water uptake when cooked with added sodium bicarbonate. Lu et al. (1984), using a sodium bicarbonate solution to soak faba beans, reported increased drained weight and increased softness while color was darker. This treatment had no effect on B— vitamin retention. A variety of salt solutions have been investigated in an effort to produce a quick-cooking dry bean (Rockland and Metzler, 1967). These salt solutions included sodium chloride, sodium tripolyphosphate, sodium bicarbonate and sodium carbonate. Using the salt solutions for soaking medium and specific soak methods, these researchers produced a product that cooked in 15 minutes. Tripolyphosphate was found most effective in reducing cook time of cotyledons. Varriano-Marston and DeOmana (1979) reported the use of four sodium salt solutions on black beans. They found the amount of sodium ion (Na*+) present during soaking did not effect the water absorption but altered the mineral content and the amount of pectic substances solubilized during soaking and cooking. Further investigation using x-ray microanalysis suggested that ion 19 exchange and chelation were responsible for softening effects. Silva et al. (1981a) reported using the four sodium salt solution was most effective in promoting softening during cooking when compared to no soaking or distilled water soak. Sodium bisulfite was found to have a detrimental effect on vitamin B6 retention although this treatment produced an improvement in color (Daoud et al., 1977). pfl, Addition of acid to soaking medium has been investigated by many researchers. Snyder (1936) used hydrocholoric and acetic acids in various concentrations for soaking and found decreased water absorption and very tough seed coats. In her study, oxalic acid was found to soften the seed coat but this product was not feasible for consumption. Soaking in the presence of citric acid yielded improved color in canned beans and also resulted in a decreased drained weight with increasing acidity (Luh, et al., 1975). It is suggested that the citrate ion complexes with iron and copper making them unavailable to react with phenolic compounds thus controlling off color development. An increase in bean firmness was noted by Nordstrom and Sistrunk (1977) for beans processed in a tomato sauce of pH 5.0 to 5.2. Junek et al. (1980) also found an increase in firmness and improved color in navy beans when soaked in an acidic solution of citric or malic acid. varriano-Marston and DeOmana (1979) reported a decrease in pH of soak water during the soak period resulting from a loss of hydrogen ion 20 in the cellular component of the beans. The changes of pH in soak water medium influences the amount of water absorption. Nutritional analysis showed soaking black eyed peas at pH ranging from 4.5 to 8.5 had no effect on vitamin retention (Kilgore and Sistrunk, 1981). They also noted that tenderness increased with increasing pH. Minerals. Snyder (1936) reported that the addition of sulphates and chlorides of calcium and magnesium at 100 ppm, resulted in depressed water absorption and hardened seedcoats. A positive correlation was found between increasing concentrations and bean firmness. The addition of calcium ions to canned foods has been well substantiated and is commercial practice for producing a firmer product (Davis and Cockrell, 1976; Luh et al., 1975). Splitting of glycosidic bonds by B-elimination causes an increased solubility of pectic material or softening. This reaction is catalyzed by hydroxyl ions and other ions such as Ca++, Mg”, KI, citrate, malate, and phytate. Calcium can have two opposite effects on texture. First, a firming effect is caused when it links polyuronide chains to pectic substances by crosslinking the matrix. Second, it can also enhance tissue softening by the B-elimination reaction as described here. However, the net result of calcium addition is usually a firming effect (VanBuren, 1979). Quenzer et al. (1978) substantiates earlier work by demonstrating that calcium concentration was positively correlated with shear and negatively correlated with imbibition. Uebersax and 21 Bedford (1980) presented supporting data showing that with increasing calcium concentrations, beans were firmer and when calcium was added in the presence of heat the firming effect was even greater. As previously stated, VanBuren (1980) found an increase in the number of calcium binding sites after treating with a blanch of 71 and 93°C. Addition of CaC12 to soak and brine waters has contributed to a significant reduction in seed coat splitting of kidney beans (VanBuren et al., 1986). Levels of 150 to 350 ppm CaClz resulted in lower weight gain during soaking, reduced drained weight), firmer processed beans and less seed coat splitting. COOKING_AND_ERQCESSING Many factors are involved in the cookability and resulting cooking quality of dry edible beans. Although processed beans must be cooked long enough to obtain commercial sterility, achieving product tenderness is often a problem. Many studies have looked at cookability of beans and have found some of the influential parameters to include: 1) growing conditions, variety, initial moisture content and seed size; 2) storage conditions including temperature, relative humidity and time; 3) soaking, blanching and cooking conditions. Grewins_and_§enetic_nffects. Snyder (1936) in studying great northern and pea beans, found growing location did not contribute to significant differences in cooking quality. Hosfield et al. (1984) did find significant differences in 22 drained weight, texture, and color in black turtle soup beans grown in three different seasons. Bean varieties were found to differ in genetic potential when grown in different environments (Muneta, 1964). They noted cook times differed considerably within a single variety from different locations in one season, and in different years. Size of been has been examined to determine its effects on cookability. Larger seed could cook more slowly due to its mass, however, Snyder (1936) and Morris (1963) found seed size negligible in cook time. Storage__£ffects. During storage of dry beans, temperature, relative humidity, initial moisture and time are critical factors in preserving good cooking quality. Snyder (1936) reports Optimum storage conditions to include a tightly closed container held at 45°F. Morris and Wood (1956) found beans above 13% moisture had poor texture and flavor after canning when stored for six months at 77°F. Beans stored at 10% moisture or less had good cooking quality for two years. Morris (1963) also observed little change in cookability of pinto, navy and large lima beans stored with low moisture contents. In a study of cooking quality, beans with low original moisture contents (9.1- 12.2%) had higher hydration ratios (Nordstrom and Sistrunk, 1979). Beans with 16% initial moisture and steam blanched were firmer in texture which also correlates with beans that had higher drained weights were less firm. Burr et al. (1968) observed as storage temperature and initial moisture 23 content increased, the rate of hydration decreased. Later research by Antunes and Sgarbieri (1979) supported this and concluded that cook time increases with increasing storage temperature and relative humidity. Burr et al. (1968) presented a dramatic increase in cook time of pinto and navy beans stored in adverse conditions. Pintos showed a fourteen fold increase in cook time from 24 minutes when fresh to 340 minutes after 7 months of storage at 90°F and 14% moisture. The navy beans at 14.2% moisture required 27 minutes to cook when fresh but after 11 months of storage at 90°F took 450 minutes. When beans were stored at 90°F with low moisture contents or stored at lower temperatures, there was a less dramatic change in cookability. Moscoso et al. (1984) reported that softening rate of kidney bean decreased with increasing time of storage. Researchers agree that legumes stored at high temperatures and high humidities accelerate the increased cook time or hard to cook phenomena. These environmental conditions are similar to those found in the tropics where legumes are a major source of protein. Storage under these conditions can lead to mold growth, development of off flavors, lipid oxidation, darkened color and development of hardshell (Morris 1963; Muneta, 1964; Burr et al., 1968; Molina et al., 1976). The cause of hardshell development is not well understood but the phenomenon occuring is defined when a seed fails to imbibe water within a reasonable time when it is moistened (Bourne, 1967). Beans stored at low 24 temperature (4°C) or at low moisture content (8-10%) in a low relative humidity environment have less occurrence of hardshell condition (Burr et al., 1968; Ken, 1968; Morris and Wood, 1956; Muneta, 1964; Molina et al., 1976; Antunes and Sgarbieri, 1979). Bourne (1967) observed that hardshell beans tended to be smaller in size than non-hard shell beans. It is suggested by some that a heat treatment before storage gave favorable results on. water absorption thus minimizing the hardshell development (Morris et al., 1950; Molina et al., 1975; Molina et al., 1976). Research conducted by Burr et al., (1968), Rockland (1963) and VonMollendroff and Preistley (1979) has shown that the hardshell condition is accelerated when beans are stored with moisture content above 13%. WW. Studies to examine cooking rates have placed much emphasis on soaking and blanching treatments. Snyder (1936) stated that beans cook more rapidly if first subjected to soaking. Her recommendation is to soak at 120°F where beans doubled in weight in five to six hours. Junek et al. (1980) reported an increase in soak temperature from 15°C to 35°C caused lower shear .press values than water blanched beans (Nordstrom and Sistrunk, 1979). In a similar study by Davis (1976) and Nordstrom and Sistrunk (1977), pintos that were not blanched or steam blanched had higher drained weights and firmer texture than those water blanched. This suggests that there is less solids leaching with the no blanch or 25 steam blanch treatments. Quast and daSilva (1977b) presented findings that hydration during soaking in black beans does not significantly decrease cook times. Soaking of peas before cooking yielded higher drained weights but had no effect on the drained weight of black beans. In another study, Quast and daSilva (1977a) noted raising the cook temperature 10°C caused a 3.36 fold decrease in cooking time for black beans. Davis (1976) reported that cook temperature had no effect on drained weight ratios or percent splits but had a pronounced effect on firmness. Light red kidney and pinto beans processed at 240°F for 45 minutes had significantly lower shear values than samples processed at 250°F for 20 minutes, regardless of blanch treatment. The opposite effect occurred for navy beans in this study. He concluded that process time had greatest effect on firmness in light red kidney and pinto beans and process temperature had the greatest effect on navy beans. Silva et al. (1981b) examined activation energies of bean softening in cooking (90—135°C) after soaking in different solutions. The 2 values for no soak, water soak, and salt combination soak were calculated at 17, 22, and 36°C respectively. Quast and daSilva (1977a) stated that cooking beans for nine minutes at 127°C gave the same result as cooking for 260 minutes at 98°C. An investigation of accelerated water uptake by Hoff and Nelson (1965) examined the effects of releasing gases by 1) steam pressure, 2) vacuum treatment or 3) sonication 26 before cooking. It was observed that during soaking the seed coat appears wrinkled and they suggest that gases fill the interstitial pores, preventing water' uptake. Steam pressure showed no effect after two minutes exposure. Vacuum treatment for short periods did cause increased water absorption. but sonication. was suggested to be the most efficient means. The quick cooking method for lima beans developed by Rockland and Metzler (1967) included loosening seed coats by vacuum treatment, soaking in a four salt solution for 6 hours, rinsing and drying. Using this method, cook times ranged from 25 to 35 minutes. SCANNING_ELECTRQN_MICRQSCQEX Microstructure does influence water absorption characteristics and texture of soaked and cooked legumes. During cooking, legumes undergo a breakdown of the middle lamella and starch gelatinization. Sefa-Dedeh et al. (1978) demonstrated with raw cowpeas that the middle lamella is stronger than the cell walls. When sliced with a razor blade in the raw state, the tissue breaks across the cell walls. As the middle lamella becomes softer with cooking it ruptures when stress is applied, leaving the cells intact. Swanson et al. (1985) stated the structure of the cotyledon changes markedly after one hour of imbibitionn During hydration the protein matrix loses its granular appearance and becomes homogeneous. Starch granules and protein bodies begin to swell and the middle lamella expands by water absorption. After soaking for 24 hours, fracturing occurs 27 exclusively around cells leaving only the exterior cell wall and middle lamella visible. Swanson et al. (1985) observed the seed coat surface of an unsoaked Sanilac beans is relatively smooth with occasional crevices and numerous pieces of amorphous material. The seed coat of an unsoaked Nep-2 bean appeared randomly rough with small clumps sticking out from the surface. .After soaking it appeared covered. with large flakes and particles of wax like material. They stated, water absorption may result in compression of cells in a smooth seed coat to cause apparent roughness. Sefa-Dedeh et al. (1978) studied the effect of heating temperature and time on the texture of cowpeas. They presented a linear decrease in maximum force required (softening) with increasing temperature (25 to 100°C). However, SEM did not show much microstructural change at these temperatures, suggesting other factors may contribute to softening. - . . ,.. I . 0;; o. o ; o -;. .. n : ,(. Quality characteristics have been observed to change over time in processed beans with the most noticeable being texture, drained weight, and percent splits. lmni et al., (1975) reported the texture of beans stored for six months was firmer than those stored for two months. It is suggested that calcium ions diffuse from the brine into the beans after canning causing a firming effect. Davis and Cockrell (1976) noted that shear’ press values increased 28 significantly from 1 day after processing to 1 month storage, regardless of the level of calcium added. However, they also noted that adding increasing levels of calcium significantly increased shear press values. Nordstrom and Sistrunk (1977) evaluated canned samples at three and six months and found a decrease in firmness at six months along with an increase in percent splits and a decrease in riboflavin. In a later study by the same researchers (1979), eight bean types were found to increase in shear press values from 0 to 6 months storage with each decreasing at 9 months. Percent splits increased over time with the greatest increases in navy, pinto, and Dwarf Horticulture #4. Vitamin E was found to decrease over time in the canned product. Soak time appears to play an important role in the quality changes during storage. In a one month study by Davis et al. (1980) pinto, small lima, and large lima beans were evaluated. Pinto showed no significant difference in drained weight or texture between one day and one month storage. Percent splits showed a significant decrease after one month storage perhaps because the splits closed to a point where they weren't detectable. Both small and large lima beans showed no significant difference in drained weight over time but they both were significantly different in texture after one month storage. Junek et al. (1980) reported drained weight of navy beans decreased slightly between 3 and 18 months of storage. Splits in pinto, kidney, and navy beans decreased with time. Shear press 29 values decreased with time but were not significant changes. The kidney and pinto beans were lighter in color and more red after 18 months. Panelist preferred kidney bean color at 18 months and pinto and navy at 3 months. TEXTURE_MEASUEEMENT Mechanical. Many instruments have been invented for measuring food texture and rheological properties. Of these instruments many have limited applications and have been replaced by fewer basic test instruments with multiple texture interpretations. By 1940 most principles of measuring food texture were established and provided a good base for developing texture measuring equipment. Use of electromechanical sensors and electronic recording systems further advanced the precision of the instruments. This lead to greater understanding of the complexity involved in the texture of food systems. Current criteria for all texture measuring instruments include a consistent means of deformation and a precise measurement of force, deformation, and time. Initial classification of texture measuring instruments can be divided into three classes depending on the type of motion used: (1) linear, (2) rotary, and (3) combined linear and rotary. Within each of these classes a further' division of types include: (1) fundamental, (2) empirical, and (3) imitative. Fundamental methods are used to evaluate a specimen in a specific way with well defined parameters of force, deformation, and time. The results are used to directly relate the nature of the specimen to 30 rheological theories. Using empirical methods, the food is subjected to a combination of stresses and the sample reaction is recorded as one value. Empirical methods are the most common used and include instruments like the Warner-Bratzler meat shear (Warner, 1928) and the Kramer Shear Press (Kramer et al., 1951). These instruments measure the force required to achieve a certain change in food ‘whereas, fundamental methods measure a single mechanical property. This total force can be a combination or sequence of stresses to include compression, tension, shear flow, or extrusion. Strict control of test parameters is required and results can only be considered comparative within a specific set of conditions. Imitative instruments are designed to simulate conditions that food might undergo such as chewing, biting or kneading. The ferces involved here are very complex and theoretical analysis is most difficult. In measuring texture of legumes, empirical methods seem most feasible and shearing devices within that class are the most popular. The Instron testing machine (Instron, Ltd.), a fundamental method, is employed for some theoretical analyses but is not feasible in many testing situations. Fresh peas are the most thoroughly studied legume in terms of texture. Financial return on the product is determined by optimizing a harvest date that gives increased yield and acceptable tenderness. The F.M.C. Pea Tenderometer introduced in 1937 was used as a means to 31 determine pea tenderness at harvest, for grading and for price paid to grower. This was the first widely adapted texture measuring instrument that used a multiblade shearing principle. The tenderometer consists of a grid of blades rotated at constant speed through a second grid. As the peas are cut by the blades, the maximum force is indicated by a pointer moving over a graduated scale (Voisey and deMan, 1976). Although this is a simple machine and easy to operate, it has been suggested that it be retired because of its lack of precision (Voisey, 1974). Muneta (1964) in determining cook time of dry beans found the tenderometer readings to vary greatly among replicates. Many researchers have continued to work on the improvement of the tenderometer but have not had real success. The most beneficial results have come from adapting existing texture measuring instruments specifically for peas. The Ottawa texture measuring system has a special version called the Ottawa Pea Tenderometer (Voisey and Nonnecke, 1972) and the Kramer Shear Press is used with a model T-1300 Tenderometer system device by Food Technology Corporation. The Ottawa texture measuring system introduced in 1971 (Voisey, 197113) was designed to achieve results such as other shear instruments but at a reduced cost. It works by a simple screw operated press that accommodates different test cells. The purpose is to provide equipment that could be used in both research and quality control applications. Voisey (1973) used the Ottawa texture measuring system with 32 a wire extrusion cell to test baked bean texture. One of the most popular and versatile texture measuring instruments is the Kramer Shear Press, developed at the University of Maryland (Kramer et al., 1951; Decker et al., 1957). This instrument has undergone many physical changes along with its name changing over the years. The basic machine is known as the "Texture Press". The system is driven hydraulically and the force is measured by a force transducer ranging from a 0 to 3000 lb capacity. The force is recorded on a strip chart recorder termed “texturecorder”. The standard cell is a box with a multiple blade unit. However various test cells can also be employed to increase the versatility of the instrument. The advantage of the force transducer is its ability to stay calibrated during wet and rugged conditions. The texture press is probably the most widely used texture instrument in legume research. Early work demonstrated it could be used to estimate the quality of processed lima beans (Salunkhe and Pollard, 1955). Continuous improvements and adaptations of the instrument allowed its use for analytical testing in the research setting (Binder and Rockland, 1964). The Instron testing' machine was introduced in 1949 (Hindman and Burr, 1949) as a general purpose testing machine for textiles, paper, plastic and rubber. Bourne et al. (1966) introduced its use for food and scientists rapidly adopted it as a measuring device. The machine basically consists of two parts: 1) a drive mechanism that 33 moves a crosshead vertically by means of twin lead screws at selected speeds; and 2) the load sensing and recording system (Bourne et al., 1966). The Instron is only suitable for laboratory work because of its sophisticated controls. It is most useful in testing basic material properties such as tension, compression, and bending. Many new applications are being tested by adapting test cells from other equipment for use with it. Voisey and Larmond (1971) tested baked beans with the Kramer shear-compression cell, a back extrusion cell, the F.M.C. Pea tenderometer, a plate extrusion cell and wire extrusion cell on the Instron universal testing machine. The results were highly correlated with sensory scores for hardness and cohesiveness. They concluded that the selection of an objective test be made on practical considerations and equipment at hand. Further' work by Anzaldua-Morales and Brennan (1982) using the Instron for measuring puncture, shear, back extrusion and compression on baked beans also found correlations with sensory measures. Back extrusion correlated with sensory firmness and chewiness and the testing was faster and more reproducible compared to the other methods. Back extrusion is used by some bean researchers to measure cooked bean firmness (VanBuren et al., 1986). Use of the Instron universal testing machine has the advantage of testing individual bean samples compared to multiple bean samples in the Kramer shear press. Bourne 34 (1972) adapted the puncture test to the Instron for simple, rapid and routine measurements of cooked dry beans. Silva et al. (1982a,b) have used the puncture test extensively and have found good correlations with sensory tests of cooked bean texture. Tmey reported an Instron puncture force of 150g (0.14 cm probe, 5cm/min) accurately defined the "eating-soft" limit of texture acceptability. A considerable drawback to this method is the numerous amount of measurements that need to be taken, with some researchers taking 500 bean punches for one mean (Moscoso et al., 1984). The Instron is the only texture measuring system today that can measure raw or cooked beans. A wedge type blade mounted on the Instron was developed by Sefa-Dedeh et al. (1978) to cut through the hard dry bean. An instrument designed especially to measure the texture or cookability of legumes was developed by Santa Mattson (Mattson, 1946; Mattson et al., 1950). This experimental legume cooker was first developed for peas but works equally well for beans. The objective of this instrument was to gather cook data for individual beans rather that a multiple bean sample. The apparatus is composed of a number of plungers, all of equal weight, that each rests upon a single bean. The cooking apparatus loaded with bean samples is lowered into a heated water bath and time for the plunger to penetrate each bean is recorded. Cook time is usually determined as the time for fifty percent of the plungers to penetrate. This cooking 35 apparatus has been used by many bean researchers and has been modified by some (Morris and Seifert, 1961; Morris, 1963; Burr et al., 1968; Burr, 1976; Jackson and varriano- Marston, 1981). Researchers at General Foods Corporation evaluated instruments that would interpret physical measurements of their subjective texture profile. This research resulted in development of the “Texturometer” (Friedman et al., 1963). This is an imitative instrument that simulates chewing and measures the changes on a strain-gauge sensing plate. They found good correlation between the instrumental values and subjective evaluations by a trained texture profile panel (Szczesniak et al., 1963). harem-Wm. To understand texture measurements with empirical instruments, consideration must go into the interpretation of total force or the force curve over time. Early instruments recorded one value of total force required which indicates little about the texture attributes involved. An instrument that could record force throughout the test would provide more information about the texture of the product. The General Foods Texturometer provided a major advance in -texture research through its use of a force-time recorder. With the Texture Profile Analysis (TPA), Szczesniak et al. (1963) correlated eight textural parameters to the force-time curve . 36 The versatility of the Kramer shear press with such a wide variety of foods along with the complex forces applied, can lead to misinterpretation of force curves. Voisey (1977) suggested, direct observation of the testing with plastic inserts to determine the mode of action during the test. Szczesniak et al. (1970) concluded that few foods would undergo a single predominate force but rather that most foods are subjected to a combination of compression, extrusion, and shear. Voisey (1977) observed canned peas in the Kramer shear press and notes that the sample is compacted to 55% of its original volume before rupturing begins. The individual peas are forced into gaps between the blades which causes their skins to split and the cotyledons to be forced apart. When the peas were compacted to 5% there was a sudden increase in force as the blades approached the cell bottom and a disproportionate amount of skins were ruptured. He concluded that the peak force was influenced by skin toughness and not shear strength of the peas. This is in agreement with Binder and Rockland (1964) for samples of lima beans with and without seed coats and with seed coats alone. Lima beans without seed coats showed no shear peak however the intact beans clearly produced definable shear peaks. Hosfield and Uebersax (1980) report similar curve findings with samples of commercial dry bean cultivars. Sensory, Many instruments have been developed to measure food texture but the results have little meaning 37 unless they can be correlated with consumer response. According to Abbott (1973), the food industry needs reliable sensory panels for three reasons: 1) to assess the relative importance of texture to the acceptability of a food item; 2) to determine the textural characteristics which are important to food; and 3) to evaluate the appropriateness of a particular objective test for a textural characteristic. Thus, subjective testing is required to evaluate and understand objective tests. In sensory evaluation there are three fundamental types of panels used for flavor, color and/or texture testing. Preference/acceptance 'tests evaluate consumer' opinions or likes and dislikes. Preference determines the preferred sample while acceptance asks "would you use this product?" Discriminatory tests evaluate only for differences that may occur between products. Descriptive tests evaluate differences and ask for a magnitude of difference between products. Descriptive testing is the most commonly used method, especially when a definition and measurement of specific product characteristics are desired. The Flavor Profile method, developed by the Arthur D. Little company (Caul, 1957) was the first scientific method introduced to characterize flavors and scale their intensities. This procedure gained much attention and pepularity. Other descriptive methods were developed using a similar approach. In the early 1960's, Dr. Alina Szczesniak (1963) lead 38 researchers at General Foods Corporation to develop a system for classifying textural characteristics. They also developed the Texture Profile Analysis (TPA) that used the Arthur D. Little Flavor Profile method as a model (Brandt et al., 1963). Texture Profile .Analysis is the basis for sensory texture evaluation today. A Quantitative Descriptive .Analysis (QDA) system introduced in 1974 by Stone et al. (1974) was designed as a modified profile procedure. This system uses extensive panel training, statistical analysis, and graphical presentation of the data. The QDA method was first reported as a successful tool in evaluating beer by sensory profiling by MeCredy, et a1. (1974). In the study of legumes, many researchers have used sensory panels in a variety of methods and in varying degrees of complexity. The simplest determination is in the evaluation of cock time. The final cook time can be determined by squeezing the been between your thumb and forefinger (Jones and Boulter, 1983) or by mastication (Binder and Rockland, 1964; Kumar, et al., 1978). Magnitude scaling tests are used on color, flavor, and overall acceptability along with texture (Morris and Wood, 1956; Silva et al., 1981a). More sophisticated means of utilizing sensory data is in the correlation of panelist data with objective measurements. Voisey and Larmond (1971) determined correlations for many objective methods in attempting to 39 select the best method to evaluate baked bean texture. The sensory testing was conducted on hardness, guminess, adhesiveness, and acceptability as described by Szczesniak (1963) and Szczesniak et al. (1963). Hardness and guminess correlated at the 5% or 1% significance level for all the objective tests. Adhesiveness was not significantly correlated. They concluded that the objective method be determined on practical and economical considerations because of the high correlations with the tests they used. In predicting an acceptable texture of processed beans, Silva et al. (1981a) found. highest correlations between puncture force from the Instron with sensory texture of black beans. A mathematical model was developed to predict sensory responses from instrumental data as follows: Sensory texture == 2.54 ln(Force) - 7.82, (r2=0.91). They predicted from the Instron puncture data that 1509 of force is ”eating soft”, while 1759 is undercooked and 125g is overcooked. Bourne (1972) reports that puncture tests by the Instron yield higher correlation coefficients with sensory scores than shear tests because of the number of measurements made on individual beans. An additional study on processed_ bean texture used firmness, chewiness, smoothness and a general hedonic rating for sensory scales (Anzaldua-Morales and. Brennan, 1982). Correlations 'with objective measures were found. Compression tests correlated significantly with sensory firmness. Significant correlations in the back extrusion test, were maximum force 40 and energy for extrusion, with sensory firmness and chewiness respectively. Shehata et al. (1983) reported significant correlations between sensory softness score and penetrometer reading (r = 0.83, P < 0.01) and between softness score and Kramer maximum shear force (r = —0.77, P < 0.01). Dos Santos Garruti and Bourne (1985) used Texture Profile Analysis (TPA) with a trained sensory panel and correlated results with the Instron for compression and puncture tests. Red kidney beans were stored at constant moisture and high and low 'temperatures for six months. Samples stored at higher temperatures were instrumentally measured. and .ranked. higher' for' hardness, fracturability, guminess, chewiness, springiness, and cohesiveness. The same beans evaluated by the sensory panel, rated higher for hardness, fracturability, lumpiness, chewiness and skin toughness. They rated lower than the control for starchiness, guminess, pastiness and moisture absorption. MATERIALS AND METHODS MW Haryest_and_fitgrage. Figure 3 provides an outline of the dry bean. handling procedure (Wilson et al., 1986). Samples of C-20 navy beans and Montcalm dark red kidney beans were harvested, thrashed, cleaned and brought to the MSU Legume Quality Laboratory from Michigan Foundation Seed Association, 2905 Jolly Road, Mason, MI and Wm. Mueller and Sons, Inc., Arthur Elevator, Reese, MI. Bean samples were stored in a temperature controlled room (25°C) until further processing. Dry_fiean_§glgr. Objective surface color of beans was obtained with a Hunter Lab Model D25 Color and Color Difference Meter (Hunter .Associates, Fairfax, VA). The color meter measures reflectance on three coordinates labeled L, aL, and bL. L measures darkness (0) to lightness (100), aL from green (-) to red (+), and bL from blue (-) to yellow (+). The instrument was standardized by a white tile with the coordinates L = +94.5, aL = -0.6, bL = +0.4. The sample was placed in. an. optically pure glass dish and covered to prevent interfering light. Coordinate values were recorded for each replicate of dry bean samples. 41 42 .emmH ..Ho no cemaa3 ”oousom .ucflmmoooum cu HOflum .mcwaocmn coon mun 3.5 :35. .532 coeoo 95 «Bow 6 m 8. new; AV E280 93262 5:5 ¢ 5.8 came >5 w Tarmac 62255 D 55:: to. soon: Loosen U 9506 En o9 >.o.mE_xocuu< .U D .coEcm_mm< oeoo b3 1 m _ .9 6 saw. mLocEmO 8:03:00 9253th E 2355 AV beacons; mEmmoooi oESoao> new :2“. 6 388m ¢ @5520 .w 9235* ¢ .85: 22“. 02.40242... ZCD .w .m ousowm 43 Initial Bear; MQLSLQIQ and mg g SQII’QS- The initial moisture contents of all bean samples were measured with a Motomco Moisture Meter AACC method 44-11 (1982), (model 919, Motomco Inc., Clark, N.J.) and by the standard AACC method for vacuum oven (AACC 44-40, 1982). The fresh weight equivalent of 1009 total solids was calculated with the initial moisture content (Equation 1), weighed, and placed into individual nylon mesh bags. Fresh weight equivalent of total solids required (9) = TQtal_sclids_renuired_igl Solids at given moisture (9) Equation 1. Calculation of fresh weight equivalent for total solids required. BEAN_SQAKING_AND_CANNING Bean samples in Study 1 and 3 were subjected to a soak treatment, filling, brining and canning procedure as demonstrated in Figure 4 (Wilson et al., 1986; Hosfield and Uebersax, 1980). figaking__fgr__§anning. Following initial moisture determination the individual samples were weighed for 100 gram solids and placed in nylon mesh bags for soaking. The soak treatments for canned beans (Study 1 and 3) consisted of 1) overnight soak (12 hours at 20 °C) and 2) 3o 30 soak (30 minutes at 20°C followed by 30 minutes at 87.8°C). The soak water was prepared from distilled water and analytical ++ reagent grade CaClz to contain various levels of Ca from 0 44 ll. SOAKING AND CANNING PROCEDURE DRY BEAN CANNING DRY BEANS (Sugar/Salt) WEIGH SOAK FILL BRINE (moosmios) 30min. 25° C 30min. 87.08 C ! ! COOL RETORT SEAL <3 EXHAUST =3 (240/45 min.) CANNED BEANS Figure 4. Bean soaking and canning procedure. Source: Wilson et al., 1986. 45 to 150 ppm (Equation 2). Following a heated soak, beans were immersed in cold water for one minute to terminate the hot soak and reduce vapor losses. Beans from both soaks were drained on perforated screen before can filling. Molecular wt. CaCl = 111.089 Ca++ in CaCl = 36.08% e.g. for water witE 100 ppm Ca++; need 0.19 Ca++7Kg water (0.1 x 100)/36.08 = 0.289 CaClz/Kg water Equation 2. Calculation of CaCl needed for water at a specified ppm Ca++ evel. Soaking. Test tube soaking of dry beans for rate of water uptake measurement was conducted in Study 2. Samples of eight beans of similar size were weighed and placed into labeled test tubes for soaking. Soaking was conducted at four temperatures including 60, 70, 80, and 90°C. At each temperature, bean samples were given one of four heated soak waters containing distilled water and 0, 50, 100, or 150 ppm calcium ion from calcium chloride. The water bath used for soaking also contained the stoppered flasks of each soak medium to maintain consistent temperatures. The soak mediums were quickly dispensed to each respective test tube. The tubes were covered and immediately placed in the water bath. Samples were removed at ten minute intervals, drained, lightly dried with tissue and immediately weighed. Percent weight gain (Equation 3) was calculated at each time interval up to 60 minutes. 46 Percent weight gain = Soaked_utl_;_lnitial_rtl * 100 Initial weight Equation 3. Calculation of percent weight gain. Can_Eillinal_Brininc_and_Exhaustine- Soaked beans for canning were rapidly transferred from individual bags to coded 303 x 406 cans. The filled cans were covered and immediately weighed for calculation of soaked bean moisture (Equation 4) and hydration ratio (Equation 5). Filled cans were transferred to a heated (98 - 100°C) exhaust box conveyor and hand filled with hot brine (90°C). The brine solutions contained 1.52% sucrose and 1.22% sodium chloride with a level of calcium from 0 to 150 ppm. The cans were conveyed through the exhaust box with a residence time of four minutes. Soaked Bean Moisture % = - ' ' ' x 100 Soaked bean weight 9 Equation 4. Calculation of percent soaked bean moisture. Hydration Ratio = - Initial bean weight 9 Equation 5. Calculation of hydration ratio. Saalingl__Thermal__£recessl__and__Sthage. From the exhaust box, the cans were loaded on a Canco vacuum closing machine (Model 6, American Can Co.) where the headspace was 47 adjusted and a lid added to produce a double seamed hermetic seal. The sealed cans were inverted and loaded into a retort basket. The full basket was transferred to the retort for thermal. processing and. to achieve commercial sterility. The retort used was a FMC vertical still retort (Food. Machinery Corp., Hooperston,' IL) equipped with an automatic temperature controller. Beans were vented for 2 minutes, processed at 115.6°C for 45 minutes, and cooled for 15 minutes in 20°C circulating water. The processed cans were dried and placed in trays for temperature controlled storage. Processed bean samples were stored for a minimum of two weeks prior to quality evaluation for Study 1” This holding period is necessary for proper bean-brine equilibration. Processed cans for Study 3 were held in 50, 70 and 90°F storage and evaluated eleven times from Day 0 to Day 306. CANNED_EBQDUCT_E¥ALUATIQN The outline for the quality evaluation of processed beans as followed for Studies 1 and 3 is found in Figure 5 (Wilson et al., 1986; Hosfield and Uebersax, 1980). WWW. All cans were weighed. to determine net weight of processed beans and brine. Vacuum was measured with a standard vacuum gauge and recorded in inches of mercury. Removal of can lid allowed measurement of headspace to the nearest 16th of an inch. WW. Drained weights were determined following the USDA method (1976). 48 Ill. CANNED PRODUCT EVALUATION Total and net weight (gm) <1 Vacuum ("Hg) <3 Headspace (1/16th") <11 Washed Drained Weight (gm) CI Subjective evaluation, clumping and splitting <13 Processed bean color (Hunter Lab Calorimeter) <1 Texture (Kramer Shear Press) '0' Total Solids (Bean residue dried for Total Solids and further analyses) Figure 5. Canned product evaluation. Source: Wilson et al., 1986. 49 The contents of each can was poured onto a U.S. standard No. 8 screen (0.094 inch opening). The entire screen ‘was immersed into 21°C water and agitated to rinse the beans and evenly distribute the sample. The screen was drained at a 15° angle for two minutes and the sample weighed on a tared scale. A drained weight ratio was calculated from Equation 6. Drained Weight Ratio = Soaked bean fill weight (9) Equation 6. Calculation of drained weight ratio. During the drained weight procedure, the beans were subjectively judged for clumping in the can and splitting of the seed coats. The beans were judged on hedonic scales of 1 to 5, with 1 = none and 5 = excessive. WWW. Processed bean color was measured with the Hunter Lab Color and Color Difference Meter in the same method as for the dry sample. Instrumental analysis for texture was performed using a TR5 texturecorder (Food Technology Corp., Reston, VA) equipped. with a No. C-15 standard multiple blade shear compression cell. Force deformation curves were plotted using a strip chart recorder. A sample size of 100 g of processed beans were distributed evenly in the cell and sheared. A typical Kramer force curve is found in Figure 6. Results for texture are reported in Kg of force/100 9 sample as shown in Equation 7. The compression and shear 50 SHEAR RESISTANCE TIME Figure 6. Typical Kramer force curve for processed beans. 51 components were measured for each sample. The relationship between the components is presented as a Ratio of Shear/Compression. Kg Force/Sample size 9 = ((Igangdngg; 29:93 1h: 3 Bange)£199)(1£g£2.294 lbs) x Force Sample size 9 Reading, Equation 7. Calculation of force required per sample size. Ig;ai__figlid§” Bean residue was used to calculate processed bean moisture and total solids. One hundred grams of residue was dried at 82°C to a constant weight in a Proctor-Schwartz cross current convection drier. Calculations of percent processed bean moisture and percent total solids are presented in Equation 8. % Processed bean moisture = W* 100 Processed Bean Residue % Total solids = 100 - % Processed bean moisture Equation 8. Calculation of processed bean moisture and total solids. WWW Samples were obtained after soaking and processing for determination of moisture, ash, and calcium content. Five grams of the soaked beans or ten grams of the processed beans were 52 evaluated for Study 1. In Study 3, all beans were separated following soaking, into cotyledon and seed coat parts. The beans were weighed into acid soaked and dried 50 ml porcelain crucibles. Samples were dried at 80°C for 24 hours in an air-oven dryer (Precision Scientific Co., Chicago, IL) for moisture determination. Samples were then ashed at 525°C for 30 hours in a Barber-Coleman muffle furnace (Model No. 293C, Thermolyne Corp., Dubuque, IA). Percent ash was calculated as in Equation 9. %Ash = __Be.sidue_w_eigbt_l_q_)___ x 100 Total dry sample weight (9) Equation 9. Calculation of percent ash on a dry basis. The ashed samples were dissolved in the crucibles with 2 ml of concentrated Baker Instra-analyzed nitric acid for one hour. The contents of the crucible was emptied to a 200 ml volumetric flask and filled to volume with distilled water. A 10 ml sample was prepared for CaH analysis using a Perkin-Elmer Atomic Absorption Spectrophotometer. To prevent Ca ionization, each sample received 1 ml of a 5% Lanthanum Chloride solution. Calculation of calcium ion in parts per million is illustrated in Equation 10. ppm Ca++ = ' ' V Dry Sample Weight (9) Equation 10. Calculation of ppm calcium from atomic absorption reading 53 WW Navy been samples soaked at 60°C and 90°C with 0 and 150 ppm calcium in the soak medium were used for SEM. Micrographs were taken of the seed coat and cotyledon cross sections to observe any structural changes related to soak temperature or calcium concentration in soak medium. The cotyledons and seed coats from each treatment were cross sectioned with a razor blade and dried at room temperature for 48 hours. The dried samples were fixed on stubs with Avery-O-Glue and Tube Coat, then coated with gold using a Mini-coater Maclin. Micrographs were taken using a JEOL JSM-35CF Scanning Electron Microscope. SENSQRX_EYALflATIQN_QE_ERQCESSED_BEANS Quantitative Descriptive Analysis (QDA) was developed in Study 1, with trained panelists to identify and quantify, in order of occurrence, the sensory properties of the product. This analysis involved extensive methods of subject selection and product evaluation techniques for texture analysis. The basic outline of the technique as described by Stone et al., (1974) includes developing a uniform product language (terminology and descriptors), a standardized evaluation procedure, conducting panelist training, statistical evaluation of panelist data, and the graphical interpretation of results. The panelists met in group discussions to develop product language and rank product attributes in the order perceived. Following these discussions, a scorecard was developed using a ten 54 centimeter unstructured line with key anchor words or phrases at each end describing the product attributes. Tb evaluate a series of samples the panelists were instructed to mark the line where it best described the perceived attribute. The panelists were seated in segregated booths with individual lighting before actual testing began. Three scorecards and reference sheets were developed for the texture evaluation of cooked bean products. Textural characteristics of‘ processed bean samples were evaluated using a) visual (Figure 7); b) masticatory (Figure 8); and c) tactile (Figure 9) techniques. Visual evaluation required inspection of an emptied can of beans for a) color, b) glossiness (sheen), c) integrity, d) clumping or matting and e) brine clarity. Masticatory evaluation on a heated sample required scoring cotyledon consistency for a) smoothness, b) moisture, c) firmness, d) seed coat toughness and e) combined resistance of cotyledon and seed coat. Finally, 10 to 12 rinsed and drained beans were evaluated by manually compressing the been between the index finger and thumb for a) resistance to rupture, b) smoothness, c) moisture, and d) uniform paste. Figure 10 is an example of the graphical.presentation used for QDA results in this study. .3 .3 .mammaoca 6>au0fiu6660 6>auoufiucmso no.6: occon h ousmam UOMOOO MO acauGSHfl>O OHDUXOU HON “ownm COCOHOHOH can OHmOOuoom Hafimfi> . 8:3: 65.... 2.. s. 53:66.:- :. 3:6. .6 66.066 2. .. 2......0 6636.655 .n 663.62.. :66: 3.356 2.666. :3 6.6:; 6... :2.) 65666 36.. 66.“. :66 66:an :6 .:6.. a:...2: .6 6.3. .6320 -II .86 ..6.66.6..6 6.6 6:66.. .6 2.66.6 66.36.86 66:60 .6 66:6 .. . ...6.0 65.0 m -66... 6.. .p 226:. a: 35.66 a. :66 6 .6 :6...6.. 62.6.. 6... c. 366.. .6 05.666 6.6.6» < .6263. o. :66 6... .32. 6:66 I- . II- 36.. 66.... :63: .56 36.. .6: :3. 362. .6 :6u.66:666 :6 :2.) :6: . 65...... .6 2.3520 4 4.2.66 6... 2. 665.66 a. .66.. 6:6». .a:...aE .6 0:.6E6.0 v 6.6..) E682. on u:..:666...6. 6:: .6.:66 2.. .66....Wofiw. Hung... 5.3 ”6.6.... 6:36. 6:66.. .6 3626.. 6... ”2.56.5 :660 .n .. 6 2.52:. 5.60 n $.56... .6 :36 .6: ”656.22.. 9.6 E...» a. 666....» :62. 6... 5...... 6. 66.066 6... ”36:33.0 :660 .m .30 >320 66.2.3256 262.6. 3.2.38.0 .566 .w 6.. :3 26.3.. :62. .6.:6...6.. 6 .6. .266 “6.6665 .o Eu... .6 66.9.3.0 6266.26 3.6.. :62. .6 6%. 6... 6. 66.6.6. .. o . 66 865...: .6 36:20.. .6 66.06.. 6... ..6.60 :30 .. .260 :30 . .......6.6 65... 6... 9.6 :62. 6... .6 2.52:. n..- 66:266....- 666..:. 2.. 5.22:. .266 $2. 6... .6 .66. 5:63.26 6.... :. 66.3556... .65.... 56.. .6. 556266 6....) 6.66:6.- 6 :. 636.62.. 6.. E... 2:53 :666 .6. 266.. .6 :66 6:0 45......) 20:30.53 mzahxuh z00..02.3¢uh .- muaciznuuh “.0 .553 002009.00 6.... :666 :6 Eu a ecu .o .. .6 62-66. 6.6 2.3.: 66.... 2. p 2... E6 6. 5:6 3:6... 6.2.3.?- ...6.. 6 2.66... .5 8:2. 2... :6 as... 56.. 6.3.6:. 6.9:: 2666 6.6. 6. 36.3.5.6. 665.66 6:: 3:95.96. 6... 36:6. .:6..6:.6>6 6.2.8. .6. .62.: 66:26.6. 6... 0:30 m.m>..(2< .m>.t.¢0mm0 m>.hm mcahxu... 21mm 03.000 6.683 2:0 2:62 56 .mamhamcfl 6>666666660 6>6666666660 66.6: 66666 662006 60 606666H6>6 muauxou 600 66666 666666666 666 666666666 6609066966: 6:26 6... 56.. >52: >0... 6.6 .0 6366.626 .630. 6:666 2.. 06 ”6532.6 6:6 2.6 .6... 2.. 65.66 06:26.66. .6 66.666 6... ”:6..66.. -662 0. 06:86.66... .660 6660 6:6 :666.>.60 6056560 .6 5366.626 .6.66. 6:6 6666.6 66.6. 6.5 ...66 .6 62666.6 6:6 52:66.. >..666. .. 6666 ”.666 6066 2.. .6 5:66:62: .0 6666 2.. “6665.666. .660 6066 .6 .6. 0.66.666 666 3666 .:366 6:6 .566. .20.: 50> 503.66 6.66.: 56> 5 6:666 .6 55666.. 6 066.6 066:6. 56> .53 62.666 65666.6 6. 66666 0... >6 62.6.5.6 66:26.66. .6 60.666 0... “666:5... .6 6.6.66 56> .65666 :666.>.66 6... .6 5.666.658 6556 66666.6. 0.6.6.6.: .0 60.666 6... 65.6.6.2 .6 >55 66 665.66 6. .. 66.66.66 6. .0 66.2666 .2655 ..656 656506 .. .. 6.6.66 56> .65666 666.66.66.66 6. :666.>.66 6... :063 0.666 5.0::6 6.0656 6 .6. 266.666 ”6605.865... .6 5:263:60 :660.>.00 .— 60. 266.660 6. 26.66 6:6 066:6. 56> 503.06 50... 660.6 6:6 66066 6 :6 66666 :02... 0. :6. 66 .6... 5.0.30.5?! 20....<:..<>u 0.5.20... .300 006.000 00... >00..02.2¢mh .- 0000.26.00» “.0 6.00..» 00200060.. >65! 11:--- i . - - 5.... 5:62.66... 6. 66:26.66: :80 6066 6:6 :666.>.00 n .6356. .0566. :66 l.II.u!..-.--2-- 1.! . : - - 2..! 5.... 6665.660» .600 6666 w :0” ill. 1.0-9:- : .. i .- -. .-....,In C...“— 66665..... 6 2.550. 2.8.2. .63 >5 0.6.6.6.... 6 3an alllllllullsc .:Ilsl Ell... 33.0 662.5625 6 52.0.2350 :060.>.60 . .65. 6660 :0 .:6 6 6:6 .6 .. .6 66.666. 6.6 66.65 66.... 6.... .65. Eu 6. 6666 6:6... 0.2.356 666.6 6 6566.6 >6 .6666 6.... :6 65.6. 50> 6.66.65 6.6566 6660 0.6. 6. 35655.6. 605.66 6.... 66655.66. 6... 36:6. .:6..66.6>6 6.6.66. .6. .6666 62.6.6.6. 6... 6560 w.m>._<2< m>.h6.¢00u0 02.35.36.560 >¢Oh(0.hm(3 20.h<34<>m 06.3th 9200 09.000 6.6.:6m 6.60 - I. 6562 .6 663666 57 .mflmaamcm m>wunwuomwa m>fiumufiucmso mean: mammn Umxooo mo cowumaau>o ousuxmu How umwnm oocmumumu 0:0 cumoouoom maauoma .m musmflm 23: 0 00.620. «6.0.2.: 6.0.6: -I 0.80.02 22.: o... a. ..o: .. «:3: 02.36... 2.. :. 632.. 23 0.2. a .0 3.2.3: .36» .0200 2.23... :9. :3 ”.235 .n .255 n 2:: .:0 .3355 38:50. ”23.2. .0203 a .o 23: 5006» 6.0.6: .83 o .oo. :9. 00 .35 .o .835. 50> 5222. 0.2.: a 056.0. .5 ”3:300:23 .m :8: 6:0 .836. :323 5.00.300 0.3.0:. 3:22.328 w 0. 08.308 8.0. .0 6:06: o... ”05.9.: o. 3:233... .. 30.. :9: 6632.0. 2.. 0.03.26 o. 0503:... 2:. 0a: .63. :3 0.3: u .236. 50> :02...... :3: 2.. 22:3. 2 85.28.... 7. as. 0:: 320600 00> -< .209... 50.. 05:96» .. an. .29. .o:.. :2... :0 Eu a 2.. 0. ..~.\. 32.6.33..- 235. .23. 0:. 9.33:. 3...? 0:. .n .. .- 02-02-3306. 08......» 65.60 a. :23 95... 306.20. 0:. 06:... 50.. 5022. :03 0:0 33... .63.. 20:15:33.0:82: 5 3:2. 2:. :o 06.! .:2. 2.6.0:. 06.60 3:03.05 .2... .o 03. 5.3 0063...: a. .3. 2.... 6.9:: :03 o... a. 30.056... 005.00 0:: 3.6.6.3. mar—.01.. o... 32.0. 62.3.26 23.6. .o. .02.. 3:20.... o... 05...: 20F(0..(>m 000.50... .200 008000 0.u>4(2< 0262:0000 02.32.5300 :05 200402.030... map—.03. . C 0000-2302. m0 hum...» 002009.00 20.h<0..<>w 0:20.. 2(u0 09.000 Iiil ..... ! 9:65 0.00 1--.! i--- a! i.-. 0602 58 am My Cotyledon Snnoflmss (ammmg CmMaanthmr VISUAL MASTICA'I'ORY Ban CMWabn hmgfiy Fines; Saflant gig; Tagheas ‘ Caflfied Bem Color Resistance thflmweTbRumna lmanPmme Mdmue Smamness TACTILE Figure 10. Graphical representation of Quantitative Descriptive Analysis results. EXPERIMENTAL Study 1: Correlation of objective and subjective measurements for defining texture of processed beans. 33523321 A three level factorial experiment was conducted to evaluate processed bean texture by objective and subjective methods. Evaluation of soak method (1. Overnight soak; 12 hrs. at 20°C and 2. 30:30 Soak; 30 min. at 20°C followed by 30 min. at 87.8°C) and calcium concentration (0, 50, 100, and 150 ppm) in soak water and brine medium, on final processed texture was conducted. Soak method, soak medium and brine medium all produced significant effects on processed bean texture. 30:30 soaked beans had increased calcium absorption, decreased drained weight, and greater measured firmness than the overnight soaked beans for all soak and brine medium treatments. Quantitative Descriptive Analysis (QDA) was effective in defining sensory attributes of processed ' bean texture. Drained weight, Kramer compression force, Kramer shear force, and measured calcium had the highest correlations with the subjective measures. These jparameters produced. multiple linear regression equations with good prediction accuracy for cotyledon firmness, seedcoat toughness, and combined resistance from 59 60 the sensory tests of QDA. INIBQDHQIIQN Texture has long been recognized as a key measure of quality in consumption of foods including processed beans. Soaking and processing methods can greatly effect the final culinary quality of thermally processed beans. Further, soak water additives such as calcium ion have shown significant alterations in final cooked bean texture. Producing optimum texture has become a primary objective of dry bean processors. To achieve this goal, texture must be defined. Consumer sensory panels can provide the best evaluation of the texture for a product but can also contribute panelist ‘variability, sample fatigue, and scheduling conflicts. Texture measuring devices can measure properties quickly, at low cost per sample, and with repeatable results. The challenge is to understand how the physical measurements describe the sensory panelist's perceptions of texture. The objective of this study was to soak and thermally process dry navy beans by two soak methods and in four levels of calcium. ion. to produce an. array of textural characteristics for subjective and. objective quality evaluation. The results will demonstrate the effects of overnight soak versus 30:30 soak on processed bean quality. Calcium concentration in the soak and brine will be evaluated for effect on bean texture and variances in uptake 61 due to soak treatment. Sensory evaluation by Quantitative Descriptive Analysis (QDA) will define consumer perceived texture. A relationship between instrumental measures and sensory textural attributes will be defined to facilitate interpretation of texture for further studies on cooking quality of dry beans. MATERIAL_AND_MEIHQDS WW Samples of C-20 navy beans were received at the MSU Legume Quality Laboratory and were handled as described by Wilson et al., (1986). Objective surface color of beans was obtained with a Hunter Lab Model DZS Color and Color Difference Meter (Hunter .Associates, Fairfax, VA). The initial moisture contents of all bean samples were measured with a Motomco Moisture Meter, AACC Method 44-11 (1982), (model 919, Motomco Inc., Clark, N.J.) and by the standard AACC method for vacuum oven (AACC 44—40, 1982). The fresh weight equivalent of 1009 total solids was calculated with the initial moisture content (Equation. 1), weighed, and placed into individual nylon mesh bags. Bean—Wins Bean samples in individual bags were subjected to a standard soak treatment, filling, brining and canning procedure as performed by (Wilson et al. (1986) and Hosfield and Uebersax (1980). soaking. The soak treatments consisted of 1) overnight soak (12 hours at 20 °C) and 2) 30:30 soak (30 minutes at 62 20°C followed by 30 minutes at 87.8°C). The soak water was prepared from distilled water and analytical reagent grade ++ CaC12 to contain various levels of Ca from O to 150 ppm (Equation 2). The soaked beans were weighed immediately after soaking for calculation of moisture (Equation 4) and hydration ratio (Equation 5). Soaked beans ready for canning were filled with a salt and sugar brine made from O to 150 ppm CaH’ water. Sealed cans were placed in a vertical still retort and processed for 45 minutes at 115.6°C and cooled for 15 minutes at 20°C. The processed cans were dried and placed in trays for temperature controlled storage. Processed bean samples were stored for a minimum of two weeks prior to quality evaluation. This holding period is necessary for proper bean-brine equilibration. MW Quality evaluation of processed beans was performed following the procedure of Wilson et al. (1986) and Hosfield and Uebersax (1980). Drained weights were determined following the USDA method (1976). A drained weight ratio was calculated from Equation 6. The beans were subjectively judged for clumping in the can and splitting of the seed coats on a hedonic scales of 1 to 5, with 1 = none and 5 = excessive. Processed bean color was measured objectively with the Hunter Lab Color and Color Difference Meter (Hunter Associates, Fairfax, VA). 63 Instrumental analysis for texture was performed using a TR5 texturecorder (Food Technology Corp., Reston, VA) equipped with a No C-15 standard multiple blade shear compression cell. A sample size of 100 g of processed beans were distributed evenly in the cell and sheared. Results for texture are reported in Kg of force/100g sample as shown in Equation 72 The compression and shear components were measured for each sample. The relationship between the components is presented as a Ratio of Shear/Compression. Bean residue was used to calculate processed bean moisture and total solids. One hundred grams of residue was dried at 82°C to a constant weight in a Proctor-Schwartz cross current convection drier. Calculations of percent processed bean moisture and percent total solids are presented in Equation 8. Samples were obtained after soaking and processing for determination of moisture, ash, and calcium content. Samples were dried at 80°C for 24 hours in an air-oven dryer (Precision Scientific Co., Chicago, IL) for moisture determination. Samples were then ashed at 525°C for 30 hours in a Barber-Coleman muffle furnace (Model No. 293C, Thermolyne Corp., Dubuque, IA). Percent ash was calculated as in Equation 9. The ashed sample was prepared for mineral analysis of Ca++ using a Perkin-Elmer Atomic Absorption Spectrophotometer. Calculation of calcium ion in parts per million is illustrated in Equation 10. 64 W K Quantitative Descriptive Analysis (QDA) was developed with trained panelists to identify and quantify, in order of occurrence, the sensory properties of the product. The basic outline of the technique as described by Stone et al., (1974) includes developing a uniform product language (terminology and descriptors), a standardized evaluation procedure, conducting panelist training, statistical evaluation of panelist data, and the graphical interpretation of results. Three scorecards and reference sheets were developed for the texture evaluation of cooked bean products. Textural characteristics of processed bean samples were evaluated using a) visual, b) masticatory, and c) tactile techniques. BESHLI£_AND_DISQHSEIQN W The mean values for dry and processed bean color are presented in Table 1. Processed navy beans became more dark (decrease L)' more red (increase aL), and more yellow (increase bL) from initial dry bean values. The mean squares for processed color are in Table 2. Soak method produced the -most significant changes in color values. Overnight soak had greater overall differences from the dry bean values in aL (more red) and bL (more yellow) than the 30:30 soak. Soak and brine medium had little effect on color change due to processing with a slight variance occurring in the 30:30 soak method with the bL value Table 1. beans: 65 Surface color analysis Soaked and brined in four levels of calcium ion. of dry 2 and processed Soak Medium Brine Medium aL Hunter_Lab_Cogrdinates_. bL 0 ppm Ca++ 0 ppm Ca++ 50 100 150 50 ppm Ca++ 0 ppm CaH 50 100 150 100 ppm Ca++ 0 ppm Ca++ 50 100 150 150 ppm Ca++ 0 ppm Ca++ 50 100 150 50. 51. 51. 51. 51. 51. .2a 51. 51 51. 50. SO. 51. 51. 51. 51. 50. 8a 1a 8a 8a 5a 3a 5a 4a 8a 8a 1a 2a 3a 4a 7a 00000 \IQQQ \ININQ' \IQQQ OVERNIGHT SOAK3 .6a .3a .6a .5a .4a .5a .5a .6a .3a .6a .0a .7a .5a .3a .4a .6a 15. 16. 16. 16. 16. 16 16. 16. 16. 16 16. 16 9b Oab 5a 4ab 2ab .lab 16. 16. Bab 4ab 2ab Oab lab .4ab 4ab .3ab 16. 16. 4ab 3ab 66 Table 1. (cont’d.) Soak Medium Hunter_Lah_gggrd1nate§A, Brine Medium L aL bL 30:30 SOAK3 0 ppm Ca++ 0 ppm Ca++ 51.5ab 4.7a 14.5fg 50 51.6ab 4.6a 14.49 100 51.7ab 4.6a 14.7efg 150 51.4ab 4.7a 14.5fg 50 ppm CaH 0 ppm Ca** 51.5ab 4.6a 14.8defg SO 51.1ab 4.8a 14.9cdefg 100 51.9ab 4.5a 15.0bcdefg 150 51.7ab 4.8a 15.5abc 100 ppm Ca++ 0 ppm Ca++ 52.2ab 4.6a 15.3abcde 50 51.9ab 5.0a 15.4abcd 100 51.0b 4.9a 15.1abcdef 150 52.23b 4.6a 15.4abcd 150 ppm Ca++ 0 ppm Ca++ 52.2ab 4.8a 15.3abcde 50 52.4ab 4.6a 15.6ab 100 51.9ab 4.8a 15.5ab 150 52.53 4.6a 15.73 1Mean values (like letters within each column for each soak method indicate no significant differences at P g 0.05 by Tukey mean separation; n = 3). 2Hunter Lab Coordinates for dry beans: L = 60.0; aL = 2.2; b = 12.0. ~ L BOVERNIGHT soar = 20°C soak for 12 hours. 30 3o SOAK = 20°C soak for 30 minutes followed with 87.8°C soak for 30 minutes 67 m~.. mo.m no.0 >0 m nmo.o omo.o mom.o we Hmsuflmmm ...m~m.. ...m.~.p ...omm.o .m pacemamxm «who.o ovo.o mmm.o m esficws mcwun x finance xm0m x coupes xmow >03 mmune ««m...o «m...o «omv.o m 530005 ocfiun x finance xmom mmo.o moo.o mm..o m asaowa mcfiun x vonums xmom «mmnmm.o nflo.o «««.-.. m finance xMOm x conums xmom ...mpm.o pmo.o .«mbm.o m. was 039 «««o>~.o ovo.o mm..o m finance mcwum «mgmvm.. mmo.o m.v.o m snaoos xmom «mammm..m «mmomo.om. «umonm.n H conuos xmom seawam.m «tamom.hm «xxmmm.fi h muommmm Cam: wmmcoom 200: an an a up gaflfidduludqluducsfi scaucauo> mo mousom .mcmmn 0mmmmooum mo manuamco uoHoc oommHSm How mocofium> mo mammamcm .N manna 68 (yellow). The mean moisture measurements for dry, soaked, and processed beans are in Table 3. The greatest amount of water absorption occurred during soaking in both soak methods. The overnight soak method had a higher moisture percentage at the end of soaking for all treatments. However after processing, both soak methods are similar in percent moisture with significant main effects shown for soak and brine mediums. These results are summarized by the mean squares in Table 4. The hydration ratio was significantly affected by soak method and soak medium while the drained weight ratio was also affected by brine medium. Quality characteristics for dry, soaked, and processed beans are presented in Table 5 with the analysis of variance for these parameters in Table 6. Soaked bean weight decreased for both soak methods with increasing calcium in the soak medium. Soak method had a significant effect on soaked bean weight with lower values for the 30:30 soaked beans. Drained weights for both soak methods were decreasing with increasing calcium and had overall lower weights for the 30:30 soak compared to the overnight soak. The dried bean weight was not significantly different between the 30:30 and overnight soaks. Some effect of calcium in the soak and brine is noted for the 30:30 soak with increasing solids retained with increasing calcium levels. 69 Table 3. Moisture measurements1 of dryz, soaked and processed beans: Soaked and brined in four levels of calcium. Soak Medium _Bsan_ucistnre__iil __Mass_Baiic_Indaxaaa Brine Medium Soaked Processed Hydration Drained .flfiiflh1__ OVERNIGHT soax4 0 ppm Ca++ 0 ppm Ca** 58.8abc 70.5abc 1.94abc 1.35a 50 59.2a 70.7abc 1.96a 1.293b 100 58.9ab 69.9bc 1.95ab 1.24b 150 58.5bcde 70.1abc 1.93bcde 1.23b 50 ppm Ca++ 0 ppm Ca++ 58.3cde 70.5abc 1.92cde 1.28ab 50 58.2de 70.2abc 1.91de 1.26b 100 58.3cde 68.8d 1.920de 1.23b 150 58.5bcde 69.7cd 1.93bcde 1.23b 100 ppm Ca++ 0 ppm Ca** 58.5bcde 71.0a 1.93cde 1.27b 50 58.5bcde 71.1a 1.93bcde 1.29ab 100 58.5bcde 70.6abc 1.93bcde 1.25b 150 58.2de 70.4abc 1.926e 1.27b 150 ppm Ca++ 0 ppm Ca++ 58.7abcd 70.9ab 1.94abcd 1.27b 50 58.06 71.1a 1.91e 1.29ab 100 58.0e 70.6abc 1.91e 1.26b 150 58.0e 70.3abc 1.91e 1.26b 70 Table 3. (cont'd.) Soak Medium W W3 Brine Medium Soaked Processed Hydration Drained W,’ l! 30 30 SOAK4 0 ppm Ca++ 0 ppm Ca++ 57.1abc 71.4ab 1.87bc 1.30s 50 56.9bc 72.1a 1.86bc 1.35a 100 57.6ab 71.4ab 1.89ab 1.28b 150 58.1a 71.1abc 1.91a 1.22cde 50 ppm Ca++ 0 ppm CaH 57.2abc 71.1abc 1.87abc 1.26bc 50 57.0bc 70.6bcd 1.86bc 1.25bcd 100 57.0bc 70.1cde 1.86bc 1.22cde 150 57.0bc 70.0de 1.86bc 1.21cde 100 ppm CsH 0 ppm Ca++ 56.9bc 70.3cde 1.86bc 1.23cde 50 56.6cd 70.1cde 1.85cd 1.21de 100 56.3cd 69.5e 1.83cd 1.20de 150 56.7bcd 69.2e 1.85bcd 1.19e 150 ppm Ca++ 0 ppm GaH 55.8d 69.7de 1.81d 1.22cde 50 56.3cd 59.28 1.8306 1.21cde 100 56.6cd 69.5e 1.85cd 1.21de 150 56.5cd 69.4e 1.84cd 1.19e 1Mean values (like letters within each column for each soak method indicate no significant differences at P g 0.05 by Tukey mean separation; n = 3). 2Initial bean moisture = 19.9%. 3Hydration Ratio = soaked beans (g)/initial dry weight (g); Drained Weight Ratio = processed beans (g)/soaked beans (9). 4OVERNIGHT SOAK = 20°C soak for 12 hours. 30 3o SOAK = 20°C soak for 30 minutes followed with 87.800 soak for 30 minutes 71 muauuqH aauum mums Hm. unquufiaz 0000 0.0 0.0 Hm.0 50.0 >0 w 000.0 000.0 0mH.0 050.0 00 Huacflmwm «mam00.0 «asm00.0 «ssN00.H «xxomm.m Hm Gmcflmamxm «a00.0 «««H00.0 mm~.0 «axamv.0 m ESHOOE OGfiHQ x szwcws Meow x 005906 £00m has mouse «««N00.0 000.0 «xmvm.0 NHH.0 0 63H006 OGflHQ x Efiflflmfi xmow 000.0 «x~00.0 hNN.0 «samm.0 m ESfiGOE OGHHQ x GOSHOE xmow xx«000.0 «ska00.0 «xxmmh.m «savom.0 m Efiflvmfi #000 x Gonvmfi xmom «aim00.0 xxx000.0 «as000.N «xxmvm.0 ma >03 039 «mavH0.0 000.0 «saOHH.m mm0.0 m EfiflGOE OGflHm «axfifl0.0 «exh00.0 sam000.m asa000.m m ESHGOE x000 «usmN0.0 «semam.0 HHN.0 «xsmam.mm H donumfi xmom «semH0.0 «as0N0.0 «««0NQ.N «xxmmm.m b mpomumm Gfimz mmMGDOm 24m: . P3 cwCfiMHQ GOHU.M.H©%~A ommmmOOHm ”we—mom MU GOHumaum> mo oousom .mcomn commoooum 0cm coxmom mo mucmemusmmme oucumwos MOM moccfiuc> mo mfimhaccm .v manna 72 no.. oo.. oops.m~ oom.mm~ om.sm~ om. mo.m oono.~ ooov.o~ oom.om~ om.smm oo. om.. oo.. om.m~ oonm..om om.smm om so.~ ooosm.m so..m~ ooo~.oom sons..mvm ++oo goo o ++00 200 on. no.. oo.. oooo.m~ oonm.vom so..mm~ om. so.~ oosm.~ ooov.m~ oom.oom moons..v~ oo. so.~ so... om.o~ ohm...m moonm..v~ om so.~ onom.m oo.mm oooo.oom ooooo..v~ ++mo goo o ++00 500 cc. so.m om.. nsm.om oo.mo~ moono..e~ om. mo.~ ooosm.~ mm..m os.mom moom.mm~ oo. so.~ comm.m oobo.o~ ooo..om som.mm~ om so.~ nos.m ooom.m~ ooh...om oooo.mm~ +.sO 266 o ++00 sun on mo.~ oono.~ oooo.mm om.om~ moon...vm om. so.~ so.v on..om pom..om nsm.mvm oo. mo.~ bos.m ooom.m~ no..o.m so.vv~ om so.m so.v oonm.m~ o~.s~m ohms.~vm ++mO and o ++00 800 o v.20.... amonmm>o muflHQm mQEdHU GOHHD @OCflMHD OOXMOm EfiHOOZ OGfiHm mauqmfi> Illllllamqlummaumlqmmm asses: xmom .cofi ssfloamo mo mao>ma H900 Ga 00mmmooum 0cm umxmow "momma commOOOHQ 0cm .mmeOm .mwuc mo .moaumwuouomucno auaamao .m manna 73 00.. 00.. 00.0m um.~sm 000.0mm 0m. £00.m 00.. 0m.0m m0m.0hm 000.0mm 00. n00.~ 00.. 00.0m m0m.>>~ 000.0mm 0m £00.~ 00.. 00m.0m m0v.m>~ 00.0mm ++00 600 0 ++0U E00 0m. 000w.. 00.. 00.0m m0..mhm 0000..mm 0m. n00.~ 00.. 0m.0m 000.00m 000.0mm 00. £00.m 00.. 0000.0m 000.05m 000.0mm 0m £00.~ 00.. on0>.0~ 0000.m0~ on~.mmm ++00 500 0 ++00 600 00. 000.m 00.. n00.0m m00.00~ onv.mmm 0m. £00.~ 00.. 0000.0m m000.~0m 00>.mmm 00. £00.~ 00.. 0000.0m 00>.0mm 00>.mmm 0m 000.~ 00.. 0000.0m 0&m.vm~ On0h.mm~ ++00 200 0 ++00 £00 on 0m.. 00.. 0000.0m 00..0mm 0m.0mm 0m. £00.~ 00.~ 000.0m n0m.m0m n00.0mw 00H 000.m n>.m 00.nm 00.m.m 000.0mm 0m 0m.~ 00.0 000.0m Am.mom on..mm~ ++00 500 0 ++00 500 0 00000 0m.0m muaamw maeaao 00000 0000000 00x0om 3:000: 0GHHm mamas; lleflmmlqmmm 2302. xmom A.0.u:oov .m 0HQ0B 74 .moussfis on so. xmom 000.50 0003 0030.000 mousoss om sou xsom ooom n 0000 om om .mssos m. sou xsom ooom n 0000 aonzmm>O¢ .A0>«mm00x0 u m .0000 u a. 0H000 00000 m .000000000000000 0000 000000 How 00000006000 H0fimfi> 0>Huo0nnsmm .oo.v~. u mosses moo. now 0:0003 ammo assumsHm ..m u 0 .00000H000m c005 >0x09 an m0.0 w m #0 00000000000 000000000Hm 00 0000000« 000005 £000 0000 000 cesaoo £000 canufi3 mu0up0a 0xfla. 000H0> c002H A.0.u000. .m 0HQ0B 75 0.00 v.mm NN.H NV.“ no.0 vm >Uw Nwo.o wm~.o omH.o www.50 th.N Hm HMSGHmmm «0gavm.o «00hw©.m «««N©©.H «*«MN©.Nmm «0*Nmb.hh @wGHMHme 030000 00000 x «««®ma.o «*«OOO.H omH.O «*00Hm.vo «000HN.mH m 850005 xMOm X GOSHwE xmom >03 0000B «afiomm.c «««N0m.o mvm.o th.mm mwm.m m 550608 000MB x .005 Mmow mmo.o «*«Hmm.a hNN.o «0mmw.mm 000NN.NH m EQHU¢E @CHHQ x .numE xmow vmo.o 0ykvmu.a «00th.m «txhom.coo «a00mm.m~ m Efifivwfi x00m X .nqu xmom «00mw0.o «*«oma.a «««®00.N «««mha.omu «0uavm.b ma >03 039 «00mmv.n «00mm©.b «iyoHH.m «000mm.m©h 000.0 m 230005 wCHHm 000mmm.o 000NmN.NH «««oov.m «««Hhm.mmmH «««©m~.®0~ m 550002 xmow vmc.c «00500.0N uHN.o «««omv.waom «00Noo.avmu H Gonumfi xmom «00mhm.o «x000m.NH «000N0.N «00omv.MMaN «*«MNH.mOm b mvommmm G062 mmM€DOm 24m: 000000 002000 00000 0000000 000000 00 00000000> ngufl> Amy pnwfiqg Cflwa MO mougom .00000 000000000 000 000000 00 000u00u00000000 0000000 000 00000H0> 00 00000004 .0 00Q08 76 Visual examination of clumping resulted in no clumping for the 30:30 soak when beans were soaked in the presence of calcium. The overnight soak produced clumping with most calcium treatments however the clumping decreased with increasing calcium levels. Splitting of bean seed coats was not different due to soak method. A slight decrease in splitting was noted at the highest level of calcium tested. Texture analysis of processed beans is presented in Table 7 with analysis of variance in Table 8. Shear and compression force increased. with an increasing level of calcium ion in the soak water and/or brine solution. Significant differences in texture occurred from the calcium ion treatments with the greatest effect occurring with the 30:30 treatment. From the Kramer force readings, shear, compression, and the ratio of shear:compression all were msignificantly affected by the soak method, soak medium and brine medium. A further analysis of bean texture as it man.- -0 relate‘swto soak method, drained weight, and the calcium treatment is presented in Figure 11. Drained weight is inverse to bean firmness for both soak methods. Increased amount of calcium ion present produces an increased firmness and decreased drained weight for both soak methods. The overnight soak shows a dramatic decrease in drained weight in the presence of any calcium but with very little weight change from 50 to 150 ppm calcium present. The heated (30:30) soak shows a greater response to calcium than the overnight soak in terms of bean firmness and drained weight. Table 7. Texture analysis 77 1 of processed beans: Soaked and brined in four levels of calcium ion. _____Kramgr_E9r00_B§adingaiiKQLlQle_____ Soak Medium Shear Compression Ratio of Brine Medium Force Force Shear:Compression OVERNIGHT SOAK3 0 ppm CaH 0 ppm Ca** 32.0ij 44.9hi 0.71g 50 31.3j 43.3i 0.729 100 37.7efghij 47.6fghi 0.79efg 150 47.60de 53.Scdef 0.89bcdef 50 ppm Ca++ 0 ppm CaH 33.8hij 46.Sghi 0.739 50 36.1ghij 51.7cdefg 0.709 100 44.2defgh 56.9abcd 0.78fg 150 56.7abc 56.9abcd 1.00ab 100 ppm Ca++ 0 ppm CaH 36.3fghij 46.5ghi 0.78efg 50 42.0defghi 49.2efghi 0.85def 100 48.8de 54.4bcde 0.90bcde 150 58.5ab 60.6ab 0.97abcd 150 ppm CaH 0 ppm Ca++ 46.7cdef 53.3000: 0.87cdef 50 45.5defg 50.6defgh 0.89bcde 100 56.3abc 57.6abc 0.98abc 150 63.7a 61.7a 1.03a 78 Table 7. (cont'd.) _____Kramer_£9rce_fieadings2(Kg/1009) Soak Medium Shear Compression Ratio of Brine Medium Force Force Shear:Compression 30:30 SOAK3 0 ppm Ca++ 0 ppm Ca++ 24.31 41.1h 0.59h 50 27.2kl 42.4h 0.64gh 100 33.6jk 47.0gh 0.71fg 150 46.7hi 54.2fg 0.86de 50 ppm Ca++ 0 ppm Ca++ 41.51j 52.8fg 0.79ef 50 51.3h 56.7f 0.90cd 100 65.19 65.8e 0.99abc 150 72.8efg 72.1de 1.01ab 100 ppm Ca++ 0 ppm Ca++ 68.5fg 72.8de 0.94de 50 75.3ef 75.5d 1.00ab 100 77.86e 73.3d 1.06a 150 90.5abc 86.2bc 1.05a 150 ppm Ca++ 0 ppm Ca++ 86.6cd 83.5c 1.04a 50 87.8bc 84.8bc 1.03a 100 97.3a 92.1ab 1.06a 150 96.2ab 93.7a 1.03ab 1Mean values (like letters within each column for each soak method indicate no significant differences at P g 0.05 by Tukey mean separation; n = 3). 2[((Transducer Force * Range)/100)(Force Reading)]/(Sample size) = Force/Sample. BOVERNIGHT SOAK = 20°C soak for 12 hours. 30:30 SOAK = 20°C soak for 30 minutes followed with 87.8°C soak for 30 minutes 79 ooo mom Com >OW 056.0 mom.m www.0m v0 Hmflvwmmm .m.fime.n «.mfimo.mmm «.mmvm.~mmn Hm pmammadxm ezflome ocean x «mmhmo.o «mhmh.ma «NHH.vN m ESflGmE XMOm x Gospmfi £60m mmk mouse «««m>0.0 «««omn.HN «««moo.®¢ m Efifiowfi wcflun x EfiHOTE xmom «mmmmo.o mmo.mH mN©.wH m Efiflwmfi QGfiHQ x 002905 xmom ««khha.o «*«mmh.QQMa «#«hom.mONN m Eflfiflmfi xflOm x UOflqu xmom «««mhm.o «xrmmv.mmm «««0Hm.v>v mu hm3 O39 «««hnv.o «««©om.mmh {tmmHN.©mmH m Sfiwcwfi mflfihm «««05®.o «gyvhm.ONmN «imho.mmmo m EfiflUOE xmom *«amua.o «««BOH.N®N© «{«MBN.0mmm a 003905 xflom «««oov.a «mrmmm.mavm «#«NNO.Nvmv b mvomumm Gfimz mmm4D0m 24m: cofimmmumeoouumonm mouom mouom cofiumfium> mo oflumm scammoumeoo Hmonm up no meadow fl can“ Mgm _n m N & .ousyxou anon commmooum now mocmaum> mo mfiwhamcm .m manna 80 F\‘b .’ 8 .unmaoz cocamuc can muzuxmu coon mo adamGOauaHmm .HH ousmwm Ecothcufimochn om? cop om o 9 mum- S (Sou/6x) emxai ueee mum g 42, oofihéxwom 88 I :Qmmoficonoow 0900 u omm .:s Egg 2955 o fimmmggxmow .6255 o ,8. «65. >> owe-.90 tam 0.588... 5mm 5 3.9.5393. 81 The heated soak produces a more linear response to the amount of calcium present producing significantly less yield and increased firmness at most treatment levels compared to the overnight soak. Presence of calcium ion produced significant differences in texture as measured by the Kramer shear press in Figune 12. Shown here are typical Kramer force curves for beans with the same level calcium ion in their soak and brine medium and for each soak method. Increasing calcium treatments produced firmer beans for both soak methods with ”the 30:30 soak beans being firmer than the overnight soaked beans. Soak method also influenced the processed texture at all calcium levels. Close examination of the curves show a change in curve type from the 0 to 150 ppm levels. Previous work by Hosfield and Uebersax (1980) characterized the curves into two types. Type A with a large shear component that is involved with the extrusion of the beans through the bottom of the shear cell. Type B curves are due mainly to compression. Binder and Rockland (1964) demonstrated with M-lima beans that the seedcoats were responsible for the shear component. At the 0 ppm level the curves are very similar in shape and .value for the two soak 'treatments. ‘With increasing calcium ion treatments the curves converge to type A and are greater in value. In 1936, Snyder demonstrated that calcium ion toughens the seedcoat, possibly explaining the emergence of a shear component with increasing calcium treatments. Shear:compression values 82 .snn em“ 0» o sown mucoeuumuu esfioaco nua3 mmem omuom can unmacum>o mo mm>u=o oouou Hmsmua Annemae .Nfi gunman “5562... 53030 cm; 8. on .8. I a a mom w I I. 9 .8 m. . m View 2955 D .8 .38 83 r -8. ohzxoh cmom >>mz pommoooi 83 presented in Table 7 represent the convergence of type B curves to type A” If the value is greater than 1.0, the shear component is larger than the compression value. Mineral analysis of dry and processed beans is shown in Table 9. A general trend for both soak methods is an increasing amount of calcium ion is measured in beans with increasing levels of calcium in the soak and/or brine mediums. Overall the 30:30 soak absorbed higher amounts of calcium than the overnight soak. These results are in agreement with previous work by VanBuren (1980) and Uebersax and Bedford (1980) where an increased amount of calcium is bound in the presence of heat, creating a firmer texture. VanBuren (1980) measured the amount of calcium binding sites in snap beans and found an increased amount of sites available following a heated blanch. Measured values of calcium are significantly affected by the soak method, soak medium, and brine medium as shown in the mean squares of Table 10 for mineral analysis. Mean ash values were mostly affected by different soak methods and showed no significant differences within soak methods. The overnight soak had higher percent ash values than the 30:30 soak. All ash values were lower than the initial ash of the dry bean indicating a loss during processing with a slightly greater loss for the 30:30 soak than the overnight soak. Calcium absorption in the overnight soaked beans was split into soak and brine effects and shown in Figures 13 and IA» Little distinction appears between the amount of 84 Table 9. Mineral analysis1 of dry2 and processed beans: Soaked and brined in four levels of calcium ion. Soak Medium Ca++ % Ash Brine medium ppm (db) W3 0 ppm Ca++ 0 ppm Ca++ 1845de 4.070a 50 1775e 3.950a 100 17749 3.900a 150 2062bcde 4.235a 50 ppm CaH 0 ppm CaH 1872cde 3.905a 50 2002bcde 3.900a 100 2273abcde 4.020a 150 2273abcde 4.130a 100 ppm Ca** 0 ppm Ca++ 2006bcde 3.960a 50 2038bcde 4.055a 100 2401abcd 4.190a 150 2422abc 4.165a 150 ppm CaH 0 ppm Ca++ 2090bcde 3.960a SO 2191abcde 3.915a 100 2526ab 3.965a 150 2711a 3.885a 85 Table 9. (cont'd). Soak Medium CaH % Ash Brine medium ppm (db) W3 0 ppm Ca++ 0 ppm Ca++ 2067e 3.765a 50 2219de 3.715a 100 2281de 3.705a 150 2315de 3.810a 50 ppm Ca++ 0 ppm Ca++ 2558cde 3.750a 50 2646bcde 3.720a 100 2984abc 3.770a 150 2839abcd 3.805a 100 ppm Ca** 0 ppm Ca++ 2835abcd 3.710a SO 3018abc 3.685a 100 3016abc 3.720a 150 3310a 3.790a 150 ppm Ca*+ 0 ppm Ca++ 3214ab 3.870a 50 3184abc 3.765a 100 3401a 3.745a 150 3246ab 3.835a 1Mean Values (like letters within each column for each soak method indicate no significant differences at Tukey mean separation; 2Dry bean calcium n = 2). 2018 ppm; Ash db 3Overnight Soak = 20°C soak for 12 hours. soak for 30 minutes followed with 87.8°C soak 4.337% 30: P g 0.05 by 30 Soak = 20°C for 30 minutes 86 Table 10. Analysis of variance for mineral analysis of processed beans. Source of CaH % Ash Variation df ppm (db) MEAN_SQHABES Main Effects 7 19.9x105*** 0.166*** Soak method 1 73.8x105*** 1.023*** Soak medium 3 17.7x102*** 0.006 Brine medium 3 40.7x10 *** 0.040* Two way 15 63.4x102** 0.018 Soak method x soak medium 3 22.4x10 *** 0.041* Soak method x brine medium 3 30.5x103 0.008 Soak medium x brine medium 9 20.8x103 0.014 Three way 3 Soak method x soak medium 9 27.0x10 0.007 x brine medium Explained 31 48.8x104*** 0.048*** Residual 54 23.2x1o3 0.013 %CV 6.14 2.93 87 .mcmmn poxMOm unaficum>o now esfioamo coon consumes Hmuou so noun: xMOm cw Esfioaco no uoomum .mH ousmum Eon zoom :. Ego-mo Omw 009 cm O M\\\. End omw o Eon om o Eon 00.. o Eng D - main 5 EEO—mo Ludd wngoleo pamseew ¥0 .msmwn poxMOm unwaswo>o HOm Esfiodmo soon cousmmoe Hmuou co ssfipms ocean aw Eswoamo mo uoomum Eon octm E 53030 omw 00.. 0m 0 88 Eon cm: 0 Egg on End 009 o Eano xaow :— EEO—mo O ¥O 00hr OOPN 00mm comm comm .vH ensues Ludd wngoleo pemseew 89 calcium absorption from the soak or brine mediums from the overnight soak. However, the greater the amount of calcium that was present resulted in a higher measured calcium for both soak and brine medium. Figure 15 demonstrates the measured calcium from the overnight soak of soaked and processed beans. The calcium treatments represented here have the same ppm calcium in their soak water and brine solution. During soaking at ambient temperatures for twelve hours the amount of calcium absorbed is very similar to the level after processing except at the highest concentration Ca++. During processing ++ the 150 ppm Ca treatment beans showed a slight increase in Ca++ absorption over the soaked amount. Thus during a long soak, the beans absorb a maximum level of calcium from the water source. Soaking is also the time when beans absorb the greatest water and as expected a greater calcium absorption along with the water transport into the bean. The measured bean calcium values from the soak and brine mediums in the 30:30 soak are shown in Figures 16 and 17. In the 30:30 soak, an increase in soak or brine calcium creates a direct increase in measured calcium. From the Figures it shows that calcium is absorbed more from the soak medium than the brine medium. In Figure 16, all lines depicting calcium in the brine are very similar in slope and close in value, representing little change due to brine. The lines of Figure 17 showing calcium in the soak differ greatly in value with increasing calcium giving increasing 90 .509 on" on o sown Esfioamo as momma commoooum can poxSOm unmasuo>o ca Esaoaao consume: ESE—mosh $5.030 empi. o9 om To... QN no. OoONv \mcmom pommooota _. mcmom pommoooi pom poxmow :. 52030 .mH ousmaa _ conga zoom o OOON N qp (wad) UOI mo .mcmon poxMOm omuom “0m Esfioamo soon consumes Hmuou co Houmz mem :H Esaoamo mo uoomum .0. owswam Edd xmom s. 832.00 00.. 00.. 00 0 91 Eda omp o End on o . Own Eon. 00¢ a End 0 n 05.5 5 53.030 ¥Uw hvm.N 00©.N mhw.m hmm.m mmh.m om HMSGwam «aaomm.b «kammh.oH kkkvmh.m «m00.0 «hum.m on O¢CHMHme unflamsmm 0H0.m 00¢.N omm.m v~N.m 5mm.v hm x Efifloamo x xmom >03 mouse 0mm.H mom.m th.N bam.v mmm.m hm #mHHmeQ x ESfiOHMU 0.0.. ahv.m mmh.H th.N mmm.m m #mfldmcmm x #000 «th.w «sMho.HH «amov.mfi Hah.m mhu.a m Efifioamo x xmom mom.N «hem.v 0H0.m 0N>.m 00¢.m on >63 039 wmm.N aamnm®.0~ «kmmm.m «akmmm.mH «ushuw.ma m mumflamnmm «kkmfin.om «kahmm.mma «kkhm~.mm «asNHN.mv «kkmom.hm m ucmeummua EDHOHMU «as0mm.oma «kaovm.mma «xaomh.mmu «somm.0m «H00.NN H ucmfiummufi xmom «kaON.Hm «kamam.0v «ksooo.mm «xxom0.NN *«kmm0.ba m“ mfiommmm 0H0: mmm IdflfiflfladUI HfldUIUflMW COOUHWHOU HO woufiom .ummu xuoumofiummz mammamsc o>wumfiuomoa 0>Hpmufiucmao wow oosmfium> mo mammamsa .e. magma 100 Table 15. Panelist meanslof Quantitative Descriptive Analysis tactile test: Processed beans were soaked in four levels of calcium ion. Cotyledon_and_§eed_ggat ppm Resistance Uniform Ca++ to Rupture Smoothness Moisture Paste OVERNIGHT SOAK2 0 6.7a 7.1a 7.1a 6.9a 50 6.1ab 7.0a 6.1ab 6.9a 100 6.3ab 7.1a 5.6ab 7.0a 150 5.1b 5.5b 4.8b 6.2a 30:30 SOAK 0 6.6a 7.1a 6.4a 7.3a 50 5.4ab 6.9a 5.4ab 7.2a 100 4.5bc 5.8ab 4.3b 6.4ab .150 3.80 5.3b 4.0b 5.6b 1Mean values (like letters within each column for each soak method indicate no significant differences at P 5 0.05 by Tukey mean separation; n = 10). 2OVERNIGHT SOAK = 20°C soak for 12 hours. 30 30 SOAK = 20°C soak for 30 minutes followed with 87.8°C soak for 30 minutes 101 m.mm ..m~ m..~ m.m~ >Uw mmv.m mmm.m mmm.. omm.m om Hmspamwm amen..o ...m~e.e .11oofi.e ...~.~.m as oosadexm umfiaosmn omo.m omn.m mvm.. vmo.m mm x Enaoamo x xmom an? mouse «mmm.v «mh~.v «amov.v m.e.m hm umflamsmm x ESAOHSU ooo.m om..e oms.~ ooo.e o umaaoomo x room moo.m mom.o voo.m mm..m m Esaoamo x xmom ammo.v «.mm.m «avom.m om..m mm mm3 O39 «rammm.m aaammm.m. «room.m aravmo.m m mumfiaosmm «xmom.NH «kammm.av «asham.mm «saovm.vm m unwfivwwufi E3HOHQU omv.o a««mom.bm mo~.> «aammfi.mm H 00:90: xwom «aaomm.m «raomm.m~ «aaoeo.m «aromm.mfi m. muOOumm can: wum<00m 24m: Symon musumfioz mmmcnuooew musumsm 0» up soaumfium> snowman Oosmumwmom mo oousom huddluuuuluququuuawuou .umou OHfiuomB mamaams< O>flynfiuomoo o>wumpausmso wow mosmflwm> mo mfimhaccm .o. manna 102 Table 17. Panelist means1 of Quantitative Descriptive Analysis visual test: Processed beans were soaked and brined in four levels of calcium ion. p131}+ WholS_Bsan _Brine_ Ca Color Gloss Integrity Clumping Clarity OVERNIGHT SOAK2 0 5.7a 4.5a 3.5a 6.3a 5.4a 50 4.9a 4.8a 3.4a 5.0a 4.6a 100 4.7a 5.3a 3.6a 5.6a 4.5a 150 4.1a 4.9a 3.2a 3.2a 4.3a 30:30 SOAK 0 4.7a 4.6a 4.4a 5.6a 2.8a 50 4.7a 3.4ab 2.8b 3.7b 2.9a 100 3.1b 2.4b 2.5b 2.5bc 2.2ab 150 1.9b 2.5b 2.5b 1.7c 1.5b 1Mean values (like letters within each column for each soak method indicate no significant differences at P 5 0.05 by Tukey mean separation; n = 10). 2OVERNIGHT SOAK = 20°C soak for 12 hours. 30 30 SOAK = 20°C soak for 30 minutes followed with 87.8°C soak for 30 minutes 103 o.mm ..mv w.mv m.mm o.mv >Uw mmm.m voo.v moo.~ .mm.v hmH.m om Hmscamwm rbmm.o «mkmom.m «mammo.o mmm.o «remem.o on pocwmamxm umfiamcmm mm~.m 0mm.m mmm.. Hom.m n.0.m mm x EDAOHOO x xmom >03 mouse mmm.m mmm.. mmo.. mmm.v vom.. mm unflaocmm x ESHOHMU mmm.~ mvm.m «afimm.m hmm.> «mom.h m umwaosmm x xmom Hom.~ mom.o. «smmm.m «.mv.o. mmv.m m ssfioamo x xmom omv.~ cum.~ mmh.m oflm.c mmm.m on >03 O38 aHOm.m «remom.>. «smohm.~m voo.m «servo.mfi m mumfiaocmm «mmh.o. «asovm.m> «ao.v.m vmo.o «raomu.>m m ucospmmuu ssfioamo «kkNHM.NNN «kxmmm.50a mv~.m «ssOMN.mCH «stoma.v® a Gonfimfi xmow «archu.0m «as0m0.mm «««¢Hm.vm «tkvvv.ofl «kkmmm.mm Ma muowmmm cflmz mmmdoom 24m: muflumao mchEsHo wuaumoucH mman HOHOU up cowumwum> IMQHHQI cuddlumonz mo oousom .umou Hmsmfi> manuamcm O>aumwuommo O>flumufiusmso How mosmfinm> mo mammamsm .m. magma 104 but whole bean gloss and integrity. The significant main effect for gloss is soak method and for integrity is calcium treatment along with panelist interaction. Graphical representations of the QDA panelists results for the overnight and 30:30 soak are found in Figures 19 and 20 respectively. Comparing the two, panelists found more significant differences in the 30:30 soak than the overnight. This result also corresponds to the larger range of measured calcium found in the 30:30 soaked beans when we correlate measured calcium with objective and subjective measures of texture. Figure 21 demonstrates the perceived differences by the panelists for the two soak methods and each calcium treatment of 0, 50, 100, and 150 ppm. Pearson correlation coefficients are presented in Table 19 for the fourteen texture attributes evaluated by the QDA panelists. Most of the sensory attributes are related to texture and they are highly correlated as would be expected. Results of the masticatory and tactile tests have the highest correlations. The visual test shows a very high correlation of clumping with the other attributes. Clumping is easily defined and detected by the panelists. The other visual attributes were either not strongly related to texture changes or more difficult for panelists to detect. In future use of QDA for bean texture, one might consider eliminating some characteristics that are highly correlated. The Pearson correlation coefficients help point out which texture attributes are expressing the same 105 Brhe Clarity Cotyledon Smooumess (mmmxbnwkkmwe MASTICATORY Cbhkdaw thwms Saxbam Thawnmw Cbnbhad Rawnwta FRmthmaFofiuMue UflwnanMe mCa' Ikkmwe Smmxhnss 53 TACTILE "'"" '°° .........15o Figure 19. QDA representation of panelist means for the overnight soak over four calcium treatments. 106 Ekhecmnfly Cbnwnawanmmmess (unwathk*Mue MASTICATORY (unwakm finnnms . tkedxnt [ Tathws / Fumbwmaa Resistance To leue UfiknnPame me hkmmue EwmeTESS ° TACTILE : '1: ‘33 ... 150 Figure 20. QDA representation of panelist means for the 30:30 soak over four calcium treatments. 107 ahsChmy omwahnSmamnmm \ \ \ \ GawabnMumue \ l \ .-' “5U“ \ \°-.. MASTICATORY \ \ M \ .. Cotyledon .\\\ \f \ . fimnam \\ ....... \ . $K' ..... a \\\ \\ \\ \\ \\\ . 3am \\_ ! Squaw! GI -. /,“=._ '1 T /’ z. / :' "~ .6.-.- 'z’: // // .. : . /,/ I!" Carbined / .' Baku“: Resistance To Euchre WON“ P8816 “dame 'Ennmmms TACTILE : .||3mm ................. aaaaamk 0 ppm Ca” Soak and Brine Mediums Figure 21a. QDA representation of panelist means for two soak methods and 0 ppm calcium treatment. 108 EieChmy CmMahnSmmmnaw cum \ \ Cotyledon Moistu'e \ .- VISUAL \ \'--. MASTICATORY . ,- \ ”h. Wham “my \\\ ",3". \ .......... chmss \\\\ \ \ ) ..: 5 \\ \\ \ \ \\ Ban a \\. E Sawmmt '0 ..u ............ ..... Bean Color Resistance 3 RanbmwnTOmeNi lmanfinw Mdmue Smmmnmm TACTILE 50 ppm Ca" Soak and Brine Mediums Figure'21b. QDA representation of panelist means for two soak methods and 50 ppm calcium treatment. 109 aheChmy CmWabnSmmmmam m“ \ X. Cotybdon Moistue VISII \ AL ..-\ \ MASTICATORY . 3.... "o, "flue-.." ' cot Bean \ t m 1.... .‘o o'. ’0'. 3'", '-, :' ....'-............ 2.. 3.." . thhdmmneTORumwe Mdmue Smmwmmm TwKTHLE —— OVWSOGK ................. 30130308k 100 ppm Ca” Soak and Brine Mediums Figure 21c. QDA representation of panelist means for two soak methods and 100 ppm calcium treatment. 110 ahBCUMy GawawnSmammmw Ohmic \ 3- ,,,,,,, 13 (bWbdmNUfiue VISUAL X 3 MASTICATORY :3: \ \ ‘-_- ................. "3.... 00' I I hwohr“\ ,3 \ \ ~33 fimnam \\$~ \\ \ ‘3 : \ \ \ \ '3 i '\\ \ \ i 5 '\ \ \ i \\ \ \ ': Bean \\\ g Seedcoat /,.-,3. Toug‘ness BamCUa' fffxfi f ”#3menhg”. Raammm Resistance TO Rupture lhflnnfinm deue téflmmmfis TIKTHLE 3 'IISOak ................ 30,30803k 150 ppm Ca” Soak and Brine Mediums Figure 21d. QDA representation of panelist means for two soak methods and 150 ppm calcium treatment. 111 Table 19. Pearson correlation coefficients for texture attributes evaluated by QDA. Masticatory 1 2 3 4 5 1)Cotyledon Smoothness ----- 2)Coty1edon Moisture .9447 ----- 3)Cotyledon Firmness .8610 .9499 ----- 4)Seedcoat Toughness .8688 .9448 .9932 ----- 5)Combined Resistance .8605 .9459 .9973 .9913 ----- 6)Resistance to Rupture .9096 .9834 .9590 .9455 .9511 7)Spreadability .8484 .9368 .8296 .8240 .8184 8)Moisture .9591 .9773 .9240 .9326 .9203 9)Uniform Paste .7930 .8673 .7164 .7094 .7035 10)Color .8442 .9246 .8934 .8815 .8934 11)Gloss .7664 .8280 .8150 .7819 .8013 12)Integrity .8688 .8806 .7870 .7752 .7656 13)Clumping .8941 .9652 .9680 .9511 .9611 14)Brine Clarity .7411 .7605 .7744 .7447 .7871 Table 19. (cont’d.) 112 Tactile 8 1)Cotyledon Smoothness 2)Coty1edon Moisture 3)Cotyledon Firmness 4)Seedcoat Toughness 5)Combined Resistance 6)Resistance to Rupture 7)Spreadability 8)Moisture 9)Uniform Paste 10)Color 11)Gloss 12)Integrity 13)Clumping 14)Brine Clarity .9302 .9646 .8643 .9467 .8514 .8632 .9780 .7762 .9138 .9356 .8908 .7470 .8132 .8957 .6461 .8497 .9327 .7810 .8425 .9410 .7543 .8523 .7327 .8576 .7725 .5698 113 Table 19. (cont'd.) 10 11 Visual 12 13 14 1)Cotyledon Smoothness 2)Coty1edon Moisture 3)Cotyledon Firmness 4)Seedcoat Toughness 5)Combined Resistance 6)Resistance to Rupture 7)Spreadability 8)Moisture 9)Uniform Paste 10)Color ----- 11)Gloss .8402 ----- 12)Integrity .7575 .8602 13)Clumping .9196 .8211 14)Brine Clarity .8548 .8646 .7957 .6107 .7946 1Correlation coefficients >0.5698 are significant at pg 0.001. 114 information for the food product. However, intercorrelation may be high with one type of food and not with another. The results presented here exclusively represent the texture of processed navy beans. 01' I' 3 S J' I' Q 1 !' Simple correlations of objective and subjective measures for texture were calculated. The objective measures that correlate best with the sensory attributes tested are drained weight, compression force, shear force, and measured calcium and are presented in Table 20. All correlations were very significant with most at pg 0.001. A general trend from this data shows a high correlation of all four instrumental measures with cotyledon firmness, seedcoat toughness and combined resistance, all from the masticatory test. To better understand the relationship between the sensory' and instrumental measures, linear regression analySes were calculated. The parameters of Equation 11 are K0 (the intercept) and K1 (the coefficient) which provides a prediction of a sensory attribute by an instrumental measure. This shows that for a unit increase in an instrumental measure, we expect a K1 unit increase in perceived texture. The strength of the relationship and the proportion of variation in the sensory attribute as 2 value. The explained by the instrumental measure is the r r2 indicates the proportion of explained variation between the dependent and independent variables. 115 Table 20. Pearson correlation coefficients for objective and subjective measures of texture. ComWnt (r11 Sensory Drained Compression Shear Measured Attribute Weight Force Force Calcium Cotyledon Smoothness .6636 .5373 .5992 .5366 Cotyledon Moisture .7085 .7225 .7751 .6757 Cotyledon Firmness .8329 .8589 .8995 .8375 Seedcoat Toughness .8352 .8463 .9003 .8452 Combined Resistance .8378 .8559 .8967 .8469 Resistance to Rupture .7319 .7859 .8133 .6932 Spreadability .5385 .6394 .6932 .5463 Moisture .7259 .7028 .7542 .6589 Uniform Paste .3855 .5362 .5613 .3501 Color .7604 .7738 .7716 .6536 Gloss .6378 .5799 .5822 .4875 Integrity .4510 .4811 .5292 .3710 Clumping .7953 .7994 .8309 .7556 Brine Clarity .7838 .5821 .5613 .5744 1Correlation coefficients >0.5750 are significant at p$ 0.001. 116 Sensory Attribute = Ko + K1(Instrumental Measure) Equation 11. Linear regression equation. Simple linear regression shows the strongest relationships with instrumental measures are cotyledon firmness, seed coat toughness and combined resistance. Linear, logarithmic, exponential, and power equations were calculated with no one method producing stronger relationships with the sensory attributes. The linear equation was most consistent and used fOr examination of multiple regression. The resulting equations for multiple regression are presented in Table 21. Multiple linear regression was calculated with stepwise regression. Drained weight, compression force, shear force, and measured calcium were the independent variables and the dependent variables were the fourteen sensory attributes. Each step of regression selects one independent variable that explains the greatest amount of variance unexplained by the variables already in the equation. Addition of variables to the prediction equation stops when inclusion criteria is not met. An indicator of prediction accuracy that gives an absolute amount of explained or unexplained variation in the equation is the standard error of estimation (SE). Table 21 shows the regression equations for the fourteen sensory attributes with physical and chemical measurements of 2 texture. From the 1: value, cotyledon firmness, seedcoat toughness, and combined resistance are best predicted from 117 Table 21. Stepwise multiple linear regression equations for objective and subjective measures of processed bean texture. Cntxladnn_amanthnaas = -7.4732 + (Drained Wt. * 0.0458) r2=0.44 s.E.=o.90 Cotxladnn_Moisture =7.9398 + (Shear Force * -0.0452) r2=0.60 s.E.=0.88 Cotyledon_£irmnaas =9.3413 + (Shear Force * -0.0720) r2=0.81 s.E.=0.84 =-2.3721 + (Shear Force * -0.05141) + (Drained Weight * 0.0358) r2=0.85 S.E.=0.76 Saadnoat.29ughnaaa =9.9329 + (Shear Force * -0.0779) r2=0.81 s.E.=o.90 =-2.9106 + (Shear Force * -0.0554) + (Drained Weight * 0.0393) r2=0.85 S.E.=0.81 =-8.9075 + (Shear Force * -0.1340) + (Drained Weight * 0.0489) + (Compression Force * 0.1238) r2=0:89 s.E.=0.70 =-20.8196 + (Shear Force * -0.1952) + (Drained Weight * 0.0719) + (Compression Force * 0.1644) + (Measured Calcium * 0.0024) r2=0.93 S.E.=0.61 118 Table 21. (cont'd.) Combinad_3asistansa =9.3493 + (Shear Force * -0.0666) r2=0.8041 S.E.=0.7860 =-2.1507 + (Shear Force * -0.0464) + (Drained Weight * 0.0352) r2=0.8490 S.E.=0.7064 Wm =7.8223 + (Shear Force * —0.0421) r2=0.6615 s.E.=o.7203 Spreadabilitx =8.0273 + (Shear Force * -0.0292) r2=0.4806 S.E.=0.7252 Moisture =7.6787 + (Shear Force * -0.0413) r2=0.5688 S.E.=0.8595 Uniform_2asta =7.8235 + (Shear Force * -0.0214) r2=0.3151 S.E.=0.7527 =4.5133 + (Shear Force * -0.0665) + (Measured Calcium * 0.0023) r2=0.5346 S.E.=0.6351 £919: . =8.0742 + (Compression Force * -0.0646) r2=0.5988 S.E.=0.8807 119 Table 21. (cont'd.) Gloss =-11.2069 + (Drained Weight * 0.0515) r2=0.4068 S.E.=1.0824 mm =4.4205 + (Shear Force * —0.0222) r2=0.2801 S.E.=0.8520 alumninn =7.5366 + (Shear Force * —0.0621) r2=0.6903 s.E.=o.9944 Warm =-17,1982 + (Drained Weight * 0.0699) r2=0.6144 S.E.=O.9647 120 the independent. measures including' drained. weight, shear force, compression force and measured calcium. Seed coat toughness is the only attribute to include all four independent measures in the prediction equation. By examining each step for seedcoat toughness, the variance is decreasing with each variable added by r2 increasing and SE decreasing. In evaluating processed beans for acceptable texture, Kramer force readings and drained weight are feasible to obtain even when testing numerous samples. Measured calcium is more time consuming and costly to obtain but as shown here a valuable measure for texture evaluation. From this study of texture jperceptions, sensory attributes of the masticatory test including cotyledon firmness, seedcoat toughness, and combined resistance were effective in defining perceived texture and can be predicted with good accuracy from instrumental measures including drained weight, Kramer compression force, Kramer shear force, and measured calcium. SHMMARX Soak method, soak medium, and brine medium all produced significant effects on. processed bean texture ‘with increasing calcium levels producing firmer beans. Overnight soak produced softer beans than the 30:30 soak in all soak and brine medium treatments that included calcium. Calcium absorption occurred more from the soaking medium than the brine medium for both soak methods with 30:30 showing a more 121 dramatic effect. The effect of heat during soaking, as in the 30:30 soak produces a difference in the amount of calcium absorbed.. The 30:30 soak allowed greater calcium absorption with decreased drained weights and increased measured firmness. The overnight soak absorbed less calcium ion, had increased drained weights and decreased firmness. Quantitative descriptive analysis was effective in defining the processed texture of beans with trained panelists by three methods including: Masticatory, Tactile and Visual Tests. The nmsticatory and tactile tests were most effective in evaluating texture of processed navy beans. Most of the sensory attributes were highly correlated indicating some redundancy in evaluation for this product. Correlation coefficients of objective and subjective data show drained weight, Kramer compression force, Kramer shear force, and measured calcium are the best objective measures of subjective descriptors used in this study. These jparameters jproduced. multiple linear regression equations with good prediction accuracy for cotyledon firmness, seed coat toughness, and combined resistance from the masticatory test. Study 2: The effect of heat treatment and calcium concentration on water and calcium absorption of dry beans during soaking. 32513321 Water and calcium absorption were measured during soaking over a range of temperatures (60, 70, 80, 90°C) and calcium ion concentrations (0, 50, 100, 150ppm). After 60 minutes of soaking, total water uptake was greatest at the lowest soak temperature (60°C) and decreasing with higher soak temperatures of 70 and 80°C at all calcium ion concentrations. Soaking at 90°C produced a total absorption greater than at 80°C but less than 60°C after 60 minutes. Within each soak temperature, higher calcium levels in the soak produced respectively lower total water absorptions. The effect of soak temperature on total calcium absorption is minimal from 60 to 80°C but at 90°C a significant increase occurs. The rates of water uptake are highest with the lowest soak temperature for all soak calcium concentrations'tested. INIBQDDQIIQN Soaking dry beans prior to cooking, aids in efficient processing and provides beneficial attributes to the final cooked product. Soak methods that can accelerate water uptake, decrease cook time, and increase processor’s yield 122 123 are most desirable. Soak treatments can provide a wide range of quality attributes in cooked beans. The objective of this study is to isolate two soak variables and evaluate them for their optimum performance during soaking. The variables chosen for study include a range of heated soak temperatures and a range of calcium ion concentrations in the soak water. Heated soaks have shown beneficial in decreasing soak times and increasing drained weights (Nordstrom and Sistrunk, 1977). The effect of calcium in processing has long been established to create a firming of texture in vegetables (Van Buren, 1979). Earlier work by Uebersax and Bedford (1980) demonstrated that adding calcium during soaking has a greater effect on firming than by adding calcium during the final processing. Based on this information, this study will specifically examine the calcium absorption during soaking alone. Also under consideration is where the calcium taken up during soaking is located in the bean. Researchers have found the seed coat to play a major role in water uptake and have shown the rate to be dependent upon calcium content, seed coat surface, micropyle structure, and initial moisture content (Saio, 1976; Hsu, 1983). Here we will examine the seed coat and cotyledon structures for total measured calcium found after 60 minutes of soaking. The goal of this study is to evaluate the effect of heat treatment and calcium concentration, on water and calcium absorption during soaking. Evaluation of been 124 microstructure during soaking at different temperatures and calcium concentrations will also be included. The results will show: first, the individual effects of heat and calcium on 'water absorption; second, the effects of heat and calcium concentration on calcium absorption; third, the interactions of heat treatment and calcium concentration on the absorption of water and calcium; and fourth, SEM micrographs depicting bean microstructure during soaking. MAIEBIAL_AND_MEIHQDS Samples of C-20 variety navy beans were obtained for testing with an initial dry bean moisture of 12.4% (db) from the AACC method 44-40, 1982. Soaking. Samples of eight beans of similar size were weighed and placed into labeled test tubes for soaking. Soaking was conducted at four temperatures including 60, 70, 80, and 90°C. At each temperature, bean samples were given one of four heated soak waters containing distilled water and 0, 50, 100, or 150 ppm calcium ion from calcium chloride. The water bath used for soaking also contained the stoppered flasks of each soak medium to maintain consistent temperatures. 3 The soak mediums were quickly dispensed to each respective test tube. The tubes were covered and immediately placed in the water bath. Samples were removed at ten minute intervals, drained, lightly dried with tissue and immediately weighed. Percent weight gain (Equation 3) was calculated at each time interval up to 60 minutes. 125 Samples soaked for 60 minutes from each temperature and soak medium were separated into seed coat and cotyledon parts using a razor blade. The bean parts were evaluated for moisture and ash using AACC methods. Total calcium was measured using a Perkin-Elmer 506 Atomic Absorption Spectrophotometeru Percentage ash ‘was calculated as in Equation 9 and calculation of calcium ion in parts per million is illustrated in Equation 10. Navy bean samples soaked at 60° and 90°C with 0 and 150 ppm calcium in the soak medium were used for Scanning Electron Microscopy. Micrographs were taken of the seed coat and cotyledon cross sections to observe any structural changes related to soak temperature or calcium concentration in soak medium. BESHLIS_AND_DIEQHESIQN W Table 22 shows the water absorption over time for four soak temperatures (60,70,80,90°C) and four calcium ion concentrations in the soak water of 0,50,100,150 ppm. Water absorption follows the same pattern for each variable, however' differences exist in the total amount. of water uptake and the rate of uptake. Each test was ended after 60 minutes of soaking. When evaluating soak temperature for water uptake at 60 minutes, a decrease in total water absorption occurs with increasing temperature from 60 to 80°C for all calcium levels. Thus at 60°C there is a greater amount of water 126 Table 22. Percent water absorbed in four soak temperatures and four soak calcium concentrations. Soak Temperature Time_(minute§) Soak Calcium 10 20 30 40 50 60 60°C 0 ppm 53.4 62.5 73.8 77.4 83.7 83.7 50 46.6 62.3 69.5 73.5 79.7 80.7 100 41.8 58.9 68.1 71.8 77.0 79.9 150 44.4 60.0 67.1 73.3 72.8 75.7 70°C 0 ppm 53.5 66.2 72.9 76.7 77.4 76.7 50 55.7 61.6 71.0 74.0 76.8 75.6 100 53.1 59.9 67.3 72.0 72.9 74.4 150 49.4 57.6 65.5 69.3 70.3 72.5 80°C 0 ppm 54.4 65.7 69.6 71.9 76.4 74.8 50 51.1 63.0 69.1 69.2 72.0 71.9 100 46.0 58.4 63.7 66.2 69.5 70.5 150 40.9 57.4 61.8 64.1 69.0 70.3 90°C 0 ppm 55.4 68.6 75.9 79.1 81.8 84.2 50 55.4 63.4 66.2 73.3 76.8 77.1 100 49.5 63.5 66.2 68.6 71.9 72.5 150 45.5 59.2 61.4 67.8 69.6 72.1 127 absorbed than at 70°C and 80°C (60>70>80). At the 90°C soak temperature, water absorptions are elevated and do not follow the general decrease in absorption with an increase in temperature found at lower temperatures after 60 minutes. In the absence of calcium, the water absorption at 90°C equals that at 60°C. It appears from the data that at the 90°C soak, a combined effect of heat and calcium on water absorption occurs from 50 to 150 ppm. The values from the 90°C soak do not follow the same trends recorded from the 60 to 80°C soaks. Changes that occur' in. the Ibean microstructure at the 90°C soak may cause the decrease in the rate and eventually the amount of water absorbed. Earlier work has suggested that this is the temperature range of starch gelatinization for beans (Hahn et al., 1977), and may explain differences in water absorption at this temperature. Gelatinatization Of starch allows increased water absorption, but in this case is restricted by some mechanism as the total amount at 90°C is not greater than at 60°C. Only with zero calcium present is the absorption slightly greater than the 60°C amount. This suggests that calcium binding is occurring with the heated soak and causing a reduced amount of water to be absorbed. By examining the measured calcium data, it is clear that a significant increase in calcium absorption occurs in the 90°C soak. 128 W The effect of soak calcium level on water absorption after 60 minutes of soaking, follows the same order for all four soak temperatures. Increasing levels of calcium concentration in soak water produced lower water absorptions for all temperatures studied. (water absorption 0>50>100>150 ppm Ca”). This generally holds true during the entire duration of the test however, a few non significant inversions are found. BEE I E S 1 I 3 Q J . El 3. Figure 22 demonstrates the effect of soak temperature on calcium absorption for the whole bean. Slight changes in total measured calcium occur in the 60 to 80°C soaks. The 90°C soak shows a dramatic increase in total measured calcium.*with increasing amounts in each respective soak calcium from 0 to 150 ppm. Research has shown that the seed coat plays a major role in soak water uptake and is also a possible site for calcium absorption (Saio 1976; Sefa-Dedeh and Stanley 1979b; and Hsu 1983). Previous work has demonstrated that beans soaked and processed in high levels of calcium produce intact, tough seed coats (Van Buren et al., 1986). VanBuren (1968) stated that concentration of calcium strongly influenced the amount of calcium uptake in snap beans. After 60 minutes of soaking, the bean parts were separated and tested for total calcium to evaluate if calcium absorption was mostly in the seed coat or cotyledon during 129 .mcofiumuucoocoo COH ssfloamc HSOH CH was mousumuomfiou usow um mnflmem mcfl3OHHOw Emma CHOC3 on» Ca coflunHOmnm eafloamo 0o ouaumuonEo... 00 00 0h 00 . . . i 000.. IlIIIIlllllllllllllllllllllllll . CONN .000N .0000 Eon om.. o Ede cm 0 . GOV” EGG GDP 0 EQQO I xmom :. 82030 0000 ED.U._> .NN oppose (qp) uidd u0| wngouaa 130 soaking. Figure 23 shows the measured calcium values in the seed coat over soak. temperatures. At. all calcium soak levels, there is a depression in measured calcium from 60°C soak to 70°C. At the 60 and 70°C soaks, the 100 ppm calcium level has greater measured calcium in the seed coat than found for the 150 ppm soak. In the 80 and 90°C soaks, the measured. calcium increases ‘with increasing soak. calcium. Figure 24 shows measured calcium in the cotyledon. Only the total amount of calcium absorbed changes for each soak concentration until the 90°C soak. At this temperature, a significant increase occurs in measured calcium in both the seed coat and cotyledon. This follows the findings of VanBuren (1968), who found that the higher the blanch temperature, the greater the rate of calcium uptake when at 71 to 100°C. Variances in measured calcium in the seed coat can be expected due to the amount of solute passing through during absorption. In contrast, the cotyledon appears to absorb water and calcium in a slower, more controlled manner and results such as found here would be expected. 091001! e e 0., . .ll .99 -"_e- ._ -,,‘ a, A. : hummus Soak water temperature and calcium concentration can each produce significant effects on final bean quality during soaking. A goal of this study is to understand the combined effects of calcium and temperature during soaking. At all soak temperatures, increasing levels of calcium decreases water absorption. When no calcium is present in 131 .mcofiumuusoosoo COa sawoamo snow Ca can mOHSHMHOQEou HSOH us unemem @CA3OHHOH anon ecu no umoo comm ecu Cw :OflumHOmns snaoano .mm ouzuwm 0o ouaunueaEOh om or on o6 com». 0 come. m m. oomeu m nv nu comma d Au m sea o2. E: o... .. comma ) Eon 00rd Enao .- D. .300 :. EEO—no lq\ 000k“. ED.U._._.00 .vm Ousmwm (qp) qud u0| LUMOlBQ 133 the soak water, the water uptake decreases with increasing soak temperature from 60° to 80°C. At 90°C, the water absorption is slightly greater than the amount at 60°C. This is possibly the result of reaching the gelatinization temperature of starch and requiring increased water uptake for the swelling of the starch granules. This may create a stronger gradient for water uptake in the bean. In the presence of calcium at 90°C there is increased water uptake at 60 minutes compared to amounts at lower temperatures but it is restricted, possibly by the calcium present as shown in Figure 25. In soak waters with calcium at the 60, 70, and 80°C soaks, increasing temperature decreases water uptake as with the 0 ppm soak water. At 90°C soak, the water absorption does not follow the pattern of increased soak temperature with decreased water absorption. However, it does follow that water uptake decreases with increased calcium concentration in the soak water. Over the same 60 minute soak period, the water absorption is highest at the 0 ppm level and decreases proportionately with increasing calcium concentrations. Bate_2f_flater_nntake After 60- minutes of heated soak, the water uptake slows, after where there appears to be an exponential decline in rate with 150 ppm soak calcium showing the most dramatic effect. Table 23 presents the best fit regression lines for each of the soak treatments, fit to the equation: Water Uptake (y) = log(time) + b. Correlation coefficients 134 .mcofiumuucoocoo cow eafioamo HSOm can mousunuomsmu HSOm up mCHxMOm mo mouasws on wound oxmuns Houm3 unmouom Eda xmom :. 53.030 0m.. 00.. 00 0 00. 0&0 00a 00.. odd—:0... know 95 exeidn 1919M .mm ousmam 135 Table 23. Simple regression lines for soak treatments. Soak Temperature Soak Calcium Intercept Slope r2 60°C 0 ppm 10.709 41.803 .989 50 3.296 44.314 .995 100 -5.572 48.639 .996 150 6.130 40.244 .984 70°C 0 ppm 24.038 31.519 .968 50 26.411 28.921 .976 100 23.817 28.985 .990 150 18.222 31.176 .992 80°C 0 ppm 28.437 27.331 .980 50 26.436 26.834 .965 100 16.052 31.389 .990 150 6.409 36.680 .982 90°C 0 ppm 19.698 36.893 .994 50 25.296 29.416 .986 100 23.006 28.685 .975 150 13.265 33.404 .989 136 were found to be better than r2 = .96 for each soak treatment. Rates of water uptake are computed as dy/dt. Although this equation may not reflect the true "kinetic" relationship between the soak time and water absorption, the good fit found here suggests that it does provide a useful estimator for this process. The lepe of the best fit line is therefore a relative indicator for rates of water absorption. The rate of water uptake is highest at 60°C for each soak calcium concentration used. .At 70, 80, and 90°C soak temperatures, in the presence of calcium, the rate of water uptake increases with increasing calcium. .A jpossible explanation is that the increased calcium in the soak could increase the rate of calcium uptake by the bean. WW Scanning electron micrographs may provide a useful tool in understanding the water and calcium uptake during soaking. Those prepared from this study are presented in Plates 1 and 2. Samples represent the cotyledon and seed coat portions from the 60 and 90°C soaks at 0 and 150 ppm Ca++ concentration soaks. Plate 1 represents the top and bottom of the seed coat soaked in the parameters previously described. In comparing the top seed coat surface by temperature, the 90°C soak and 0 ppm Ca++ appears more rough with small cell groupings protruding. Swanson et al. (1985) report the seed coat surface of an unsoaked bean is smooth with occasional 15m x1990 8088 10 EU CE087 \ l . ‘ 9118 3119.55‘ceoé7. 3 f . 30$ . - . :3 one: *NBWJETV . Plate 1. Navy beans: Top of seed cost (a—d) and bottom of seed cost (e-h) following soaking at two temperatures and in two calcium concentrations. A a E - 60°C/0 ppm, B a F - 60°C/150ppm, c a G - 90°C/O ppm, D a H - 90°C/150 ppm. 138 crevices and numerous pieces of amorphous material. After soaking 24 hours the roughness or waviness is enhanced with swelling of individuals cells into pod like groupings. After soaking, Nep—Z beans appeared covered with large flakes and particles of wax like material. Water absorption may result in a compression of cells in a smooth seed coat to cause apparent roughness (Swanson et al., 1985). The bottom side of the seed coat showed no apparent differences between soak temperature and calcium concentration. The cotyledon portion of the bean undergoes noticeable structural changes during soaking. Many researchers have shown the basic structures to appear in raw beans as starch granules, protein bodies, cell walls, and middle lamella (Rockland and Jones, 1974; Sefa-Dedeh et al., 1978; Sefa— Dedeh and Stanley, 1979c). Cell walls are composed mainly of pectic substances and hemicellulose. The middle lamella, which cements the cells together, consists of pectic substances associated with divalent cations such as calcium or magnesium and proteinaceous material. Sefa-Dedeh et al. (1978) reported that cowpeas soaked and. heated to 50, 70 and 90°C showed little change in microstructure: Micrographs of these cowpeas show that when sliced with a razor, the fracture occurs at the cell wall exposing the interior cell because of the strong middle lamella. When cowpeas are heated and soaked to 100°C the fracture occurs at the middle lamella due to softening leaving most of the cells intact. 139 Plate 2 displays micrographs of the cotyledons that were in 60 and 90°C soak water with 0 and 150 ppm Ca++ for 60 minutes. There appears to be little microstructural Change due to the amount of calcium present during this soak period between the temperatures studied. Significant microstructural changes do occur between soak temperatures. It appears that at the 60°C soak when sliced, it fractures across the cell wall and at the 90°C soak it fractures at the middle lamella leaving some cells intact. These findings agree with those previously reported by Rockland and Jones (1974) and Sefa-Dedeh et al.,(1978). From close examination of Plate 2 at 90°C, some differences may appear due to calcium level. At the 0 ppm Ca++ there are less intact cells compared to the 150 ppm soak. It is difficult to determine if the fracture occurs at the middle 1ame11a or the cells walls. The cell walls appear ‘very fragmented. possibly due to high temperature soaking. Rockland and Jones (1974) reported that a short heat treatment loosened the middle lamella to allow separation of individual cells without rupture to the cell walls. Perhaps 60 minutes was too severe and damaged the cell wall structure while the 150 ppm soaked beans had the calcium to help protect its' integrity. It is well documented that divalent cations bridge to support the pectinaceous matrix between cells (Rockland and Jones, 1974). ‘~~\ \_ 3'\--. Q, / . “y“? K is" jwoea4'1aorou ceoe Plate 2. Navy beans: Cross section of cotyledon (a-d) following soaking at two temperatures and in two calcium concentrations. A - 60°C C/O pm 60°C/150 ppm, c - 90°C/0 ppm, D - 90 c/150 ppm. 141 There are no obvious differences between calcium concentrations at the 60°C soak after 60 minutes. This heating is gentle and causes less softening and cell rupture. Differences may occur when judging time to achieve desired softness. The calcium ions will prevent the intercellular breakdown which is related to bean softening by many researchers. Rockland and Jones (1974) and Sefa- Dedeh and Stanley (1979C) both report that textural characteristics of whole beans are also dependent upon mechanical stresses due to starch gelatinization and protein denaturation which may or may not facilitate cell separation but does contribute to the uniform smooth texture of softened beans. SDMMABX Heated soak: treatments and. calcium. concentration in soak waters have shown to produce differences during bean soaking. Water uptake is decreased with increasing temperatures from 60 to 80°C. At 90°C the absorption level is increased compared to soaks from 60 to 80°C. Calcium concentration in soak water effects water uptake with higher calcium. concentrations lowering' the water' uptake at all temperatures studied. Calcium uptake does not appear to be a function of temperature between 60 to 80°C but is at 90°C where a significant increase occurs. At 60, 70, and 80°C soak, water uptake decreases with increasing temperature at all soak calcium levels. At the 90°C soak, water uptake is greater for the 0 ppm soak level where it is slightly 142 greater than the 60°C soak. The water uptake for the 90°C soak decreases proportionately with increasing calcium levels. Changes that occur in the bean microstructure due to gelatinization may cause the decrease in rate and the amount of water absorbed at the 90°C soak. Rate of water uptake is highest at 60°C for all calcium levels tested. The rate of water uptake increases with increasing calcium in the 70, 80, and 90°C soak while in the presence of calcium. The increasing calcium levels in the soak could create a stronger gradient for equilibrium into the bean. SEM micrographs did show visable changes in bean microstructure due to soak temperature. Little change was observed due to soak calcium. Beans from the 60°C soak when sliced, fractured at the cell wall and those from the 90°C soak fractured at the middle lamella. This agrees with previous work on beans heated and soaked up to 100°C where the middle lamella is softened and leaves the cells intact. Study 3: Post Processed quality evaluation of dark red kidney beans subjected to different soak treatments, storage temperatures and time intervals. ABEIBAQI Dark red kidney beans were evaluated for canned product quality during 306 days of storage at 50, 70, and 90°F. Two soak methods were used in processing including 1) Overnight soak, 12 hours at 20°C and 2) 30 30 soak, 30 minutes at 20°C followed by 30 minutes at 87.8°C. The soak methods had significant effect on product quality over time. Both soak methods produced decreased drained weights over time with the 30:30 soak producing a greater decline in drained weight. The 30:30 soak had greater increases in firmness over time than the overnight soak. Drained weight and bean firmness are inversely related for both soak methods with the 30:30 soak creating the greater differential in firmness and drained weight. INIBQDHQIIQN Final eating quality of processed beans is influenced by many factors including growing environment, storage conditions, soak treatments and processing parameters. Processed beans can be evaluated by measuring texture and drained weight. After processing, the canned product may continue to undergo quality changes during storage as 143 144 reported by many researchers (Luh et al., 1975; Davis and Cockrell, 1976; Nordstrom and Sistrunk, 1977; Nordstrom and Sistrunk, 1979; Davis et al., 1980; and Junek et al., 1980), A period of bean-brine equilibration may occur after processing especially in the presence of added calcium or other ions. Calcium ions present in the brine attempt to achieve equilibrium with the bean causing a firming effect over time (Davis and Cockrell, 1976). Most research shows a decrease in drained weight over time which may be attributed to solids loss to the brine from bean breakdown or a loss of water through calcium binding in the bean during equilibrium. This study was designed to evaluate the effects of soak treatment, canned bean storage temperature and length of storage on the final eating quality attributes of processed kidney beans. Drained weight and bean texture are measured to evaluate processed bean quality. MAIERIAL_AND_MEIHQDS Dry bean samples of dark red kidneys (Montcalm variety) were obtained for testing with an initial moisture content of 13.7% (db) by the AACC method 44-40, 1982. WWW Beans were soaked and canned following the procedure of Hosfield and Uebersax, 1980. Following initial moisture determination, the individual samples were weighed for 100 gram solids and placed in nylon mesh bags for soaking. The soak treatments consisted of 1) Overnight soak, 12 hours at 145 20°C and 2) 30:30 soak, 30 minutes at 20°C followed by 30 minutes at 87.7°C. The soak water was prepared from distilled water and analytical reagent grade CaClz to contain 50 ppm Ca++. The soaked beans 'were immediately' weighed for calculation of moisture (Equation 4) and hydration ratio (Equation 5). Soaked beans ready for canning were filled with a salt and sugar brine made from 50 ppm Ca” water. Sealed cans were placed in a vertical still retort and processed for 45 minutes at 115.6°C and cooled for 15 minutes at 20°C. The processed cans were dried and placed in trays for temperature controlled storage at 50, 70 and 90°C. Samples were evaluated eleven times from Day 0 to Day 306. W Drained weight and texture measurements were conducted on days 0, 1, 4, 7, 14, 21, 54, 89, 187 and 306 days of storage. Duplicate samples. were taken from each storage temperature and two samples were taken from each soak treatment for evaluation. Drained weights were determined following the USDA method (1976). A drained weight ratio was calculated from Equation 5. Instrumental analysis for texture was performed using a TR5 texturecorder (Food Technology' Corp., Reston, ‘VA) equipped. with. a No. C-15 standard multiple blade shear compression cell. A sample size of 100 g of processed beans were distributed evenly in the cell and sheared. Results for texture are reported in 146 Kg of force/100 g sample as shown in Equation 7. The compression. and shear components were measured for each sample. BESHLIS_AND_DISCHSSIQN Table 24 shows the drained weight means for processed kidney beans soaked by two methods and stored under three temperatures. In both soak treatments the overall result for drained weight is decreasing over time. For both soak treatments there are no significant changes in drained weight due to the storage temperatures used. Soak treatment has greater effect on drained weight over time than storage temperature, as is demonstrated in Figures 26 to 28 for overnight soak and 29 to 31 for 30:30 soak. The 30:30 soak showed greater decreases than the overnight soak. The largest decline in drained weight over time occurred for the 30:30 soak between day 21 and day 28 for all storage temperatures. The overnight soaked beans showed a gradual decline in drained weight, but declines never equaled the losses encountered after 306 days in the 30:30 soak. Texture is measured. by compression. and shear force values, which are presented in Tables 25 and 26, respectively. . During the first 30 days of sampling, the beans are equilibrating with the brine and as a result, the textures are varied. After this period the beans continue to firm, possibly resulting from calcium ions forming cross bridges in the cotyledons. There appears to be no significant differences in compression force due to storage 147 1 Table 24. Washed drained weights of processed kidney beans soaked by two methods and stored at three temperatures over time. Days of Storage Temperature °F Storage 50 70 90 W2 0 295.8ab 295.7a 295.9abc 1 304.0a 297.9a 299.4abc 4 304.0a 296.2a 297.3abc 7 301.8a 303.2a 306.2a 14 302.0a 303.3a 301.0abc 21 304.9a 299.9a 305.4ab 28 300.0ab 300.0a 301.1abc 54 304.0a 298.6a 298.7abc 89 304.4a 299.6a 299.0abc 187 287.8b 292.7a 288.7c 306 293.1ab 293.1a 291.1bc 148 Table 24. (cont'd.) Days of Storage Temperature °F Storage 50 70 90 lQLiQ_fiQAK 0 292.5abc 292.4ab 292.53b 1 293.83b 293.3ab 293.3ab 4 293.4abc 289.7ab 290.3abc 7 302.58 299.56 299.53 14 296.13 294.4ab 293.13b 21 297.53 295.23 294.33 28 281.2Cd 283.8bc 279.0de 54 279.76 276.00d 275.0d 89 281.5de 283.1bC 284.9abcd 187 274.5d 274.4Cd 275.5Cd 306 276.5d 271.7d 274.2d 1Mean values (like letters within each column for each method indicate no significant differences at P g 0.05 Tukey mean separation; n =2). 2Overnight Soak = 20°C soak for 12 hours. 30:30 Soak = soak for 30 minutes followed with 87.8°C soak for 30 minutes. soak by 20°C 149 .moom um ommwoum pocnouxo mafiusc mason pomem unmasuo>o H00 unmam3 cosmono can muocsuflu soon 00 nanmcofiuoaom .0N Guzman @0330 .o 330 00m 00m 00.. 0 0 com .m 00 d o: m 00 8 00m .mM w. m. co. m w t 00w 1. .a h .. O .m. our 0 m e 6 d . e 0:” 009 .m m one one D “.000 nEo... omouoam II zoom 20.50.30 150 .0005 um commons poccmuxo onwusc meson pomem ucwwcwo>o MOM unmfio3 posflmuc can moosewwu soon «0 QanmCOaumHom .mm owsmfim ommuoum .o 330 oom oou oo. o 0 Av 00w or .w ohm on m. owe. mm m. \m. 009 N w I\ Ir 1 com o 4. h i one 0 m oom ( W .0.V.. w o; co. .m m ON” 009 D mach QEO... emmaoum II snow «30.50.30 151 .moom um omououm coccouxo oswusc mason poxSOm pzmficwo>o MOM unmfio3 cesamuo can mmoseuam soon 00 marmCOausHom 009.30 .o mann— 000 00w 00.. 0 00m 0hN 00w m. M 00w .11 .m e 000 W M. ore .m m own 0 .mm obsess 00 00 00.. 0N.. 9010:] uogsse1dwoo (5001/61) 0Q.. 00.. 00.. uo00 0E0... 002071.. II zoom 20.50.30 152 mammn vmmem OMHCm HON unmfim3 cwcflmuo cam mmmceufiu cmmn mo Qwsmcofiumamm .mm mnsoflm mamboum no mama can DON 09.. O Dow Do ohm Om SE A»). \01. Dow .N N can L O m. our 0 i 6 m com S: ( Au e 0:” Dow .m m can an. D .moom um mamuoum cmccmuxo mcausc “rem 5:: muffim II :25 canon 90105 uogssadeoo 153 .mOOF um mowuoum cmccwuxm acfiusc mammn UmeOm omuom new unmam3 cmcwmuc can mmmcsufiu :mmn mo Qanmcofiumem .om whamam mamboum .0 930 com com oo. o omu om cum on cam cop. m m omu our .m. e com av. w m 0..” 00.. .m can on. D mac» 3:3 «335 ..| gnomomuom (Boat/6x) 90105 uogssadeoo 154 .uoom um mmmuoum cmccmuxm acausc mcmwn cmmem OmHOM new uzmwm3 wmcwmuo cam mmmceuflm :mmn wo afinmcoHumawm museum ho m>mo 00m DON DO? 0 DQN CNN OQN OmN com 090 ON” Drained Weight(g) “row as: 0336 |.. snow omuom .Hm musmfim o m co m on a. m m. 2: m w ID .5 our w m Ru au 2: ( a of cm. 155 Table 25. Kramer compression force (Kg/1009)1 of processed kidney beans soaked by two methods and stored at three temperatures over time. Days of Storage Temperature °F Storage 50 410 90 W2 0 59.5e 58.9c 60.2f 1 62.9de 73.5abc 79.4def 4 62.1de 76.7abc 73.1ef 7 77.7cde 67.2bc 70.3ef 14 104.3b 75.5abc 93.0cde 21 65.7de 101.2abc 77.6def 28 79.9bcde 69.4abc 74.5def 54 86.8bcd 109.5ab 118.7abc 89 102.2bc 94.6abc 101.4de 187 79.8bcde 76.2abc 125.2ab 306 137.3a 110.1a 140.2a 156 Table 25. (cont'd.) Days of Storage Temperature OF Storage 50 7O 90 30419.5933 0 70.80 70.10 71.4b 1 75.7bc 72.10 75.4b 4 63 70 69.10 74 8b 7 68 60 75.20 69 1b 14 78.9b0 83.70 90.58b 21 71.30 76.70 72.5b 28 105.88b0 100.90 122.18b 54 136.18b 144.38 136.18b 89 147.08 139.18b 125.48b 187 150.78 104.4bc 125.98b 306 165.78 156.68 168.08 1Mean values (like letters within each column for each soak method indicate no significant differences at P g 0.05 by Tukey mean separation; n =2). ZOvernight Soak = 20°C soak for 12 hours. 30:30 Soak = 20°C soak for 30 minutes followed with 87.8°C soak for 30 minutes. 157 Table 26. Kramer shear force (Kg/100g)1 of processed kidney beans soaked by two methods and stored at three temperatures over time. Days of Storage Temperature °F Storage 50 7Q * 90 W2 0 77.2d 76.6a 77.80 1 77.4d 89.8a 97.6b0 4 73.4d 89.43 81.10 7 91.4de 77.2a 78.80 14 106.3b 83.4a 100.33bc 21 72.8d 100.9a 78.90 28 84.0de 72.1a 74.50 54 92.2bcd 108.4a 114.7ab 89 103.5bc 96.8a 98.8bc 187 79.7cd 73.4a 111.9ab 306 131.7a 116.3a 126.6a 158 Table 26. (cont’d.) Days of Storage Temperature °F Storage 50 70 90 39412.5983 0 84.80d 84.2bcd 85.1b0 1 83.7cd 82.7bcd 87.7b0 4 76.0d 75.4cd 77.9bc 7 75.2d 76.20d 72.4bc 14 80.00d 81.5bcd 87.0b0 21 75.6d 72.3d 71.80 28 81.90d 82.8b0d 88.3bc 54 94.0de 100.4ab 95.6bc 89 107.83b 97.2bc 100.13b 187 100.0ab0 84.0b0d 81.9bc 306 118.6a 122.6a 125.43 1Mean values (like letters within each column for each soak method indicate no significant differences at P S 0.05 by Tukey mean separation; n =2). 2Overnight Soak = 20°C soak for 12 hours. 30:30 Soak = 20°C soak for 30 minutes followed with 87.8°C soak for 30 minutes. 159 temperature up to 187 days. At 187 days, significant differences appear due to storage temperatures but seemingly is erroneous as the means again are not significant at 306 days. After the equilibrium period, the 90°C storage beans show a steady increase in compression force with time for the overnight soak. The 50 and 70°C storage temperatures show a significant increase in compression from day 21 to day 54 for the overnight soak. As with the 30:30 soak there appears to be significant differences due to storage temperature at day 187. There is no apparent explanation for this variation, and therefore it may represent sampling error. At day 306 for the overnight soaked beans compression force is increasing at all storage temperatures. The 30:30 soak increases in compression force over time with a significant increase from day 21 to day 54 for all storage temperatures. Overall, the 30:30 soak was found to cause a greater compression force value than the overnight soak. Similar to the findings of Study 1, drained weight is inverse to bean texture for both soak methods as shown in Figures 26 to 28 and 29 to 31. Over time the drained weight is decreasing and firmness measured by Kramer compression force is increasing. The overnight soak 'has a gradual decline in drained weight and increase in firmness. A sudden change occurs for the 30:30 soak in drained weight and firmness between 2 and 3 weeks of storage. This change shows the dramatic inverse relationship of the two 160 measurements. Following this inversion, the slope slightly changes over time with the drained weight decreasing and the firmness increasing. The shear force values for both soak methods follow similar curves and means (Table 26). There is an overall increase in shear force over time for both soak methods and all storage temperatures. Shear force has been reported to correlate with seedcoat toughness. Therefore we would expect more differences in compression over time with equilibration of calcium in the cotyledon. SHMMARX The effect of soak method and storage temperature on final processed bean quality was evaluated. Soak method produced more significant differences in the quality attributes measured than storage temperature. Storage temperature of the processed beans showed no definite relationship to quality changes over time. The overnight and 30:30 soak produced decreased drained weights over time. The 30:30 soak had greater losses in drained weight than the overnight soak. The 30:30 soak also had greater increases in firmness than the overnight soak over time. A possible explanation lies with the increased availability of calcium binding sites in the heated soak beans (30:30 soak) thus allowing more calcium binding and possibly forcing water molecules out. SUMMARY Soak method, soak medium and brine medium all produced significant effects on processed bean texture. Soak method produced significant differences in quality changes over extended storage but storage temperature showed no definite relationship to quality changes over time. Overnight soak produced softer beans than the 30:30 soak in all soak and brine treatments. Calcium absorption occurred more from the soak medium than the brine for both soak methods. The 30:30 soak allowed greater calcium absorption with decreased drained weights and increased measured firmness in both Studies 1 and 3. The overnight soak absorbed less calcium, had increased drained weights and decreased firmness. For overnight and 30:30 soaked beans, an inverse relationship is demonstrated between drained weight and bean texture. The overnight and 30:30 soaks both produced decreased drained weights over time. Quantitative Descriptive Analysis was effective in defining processed bean texture with the masticatory and tactile tests being the most effective. Correlation coefficients of objective and subjective data show drained weight, Kramer compression force, Kramer shear force, and measured calcium are the best objective 161 162 measures of subjective descriptors used in this study. These jparameters jproduced. multiple linear regression equations with good prediction accuracy for cotyledon firmness, seed coat toughness, and combined resistance from the masticatory test. Heated soak. treatments and calcium. concentration in soak waters have shown to produce differences during bean soaking. Water uptake is decreased with increasing temperatures from 60 to 80°C. At 90°C the absorption level is increased compared to soaks from 60 to 80°C. Calcium concentration in soak water effects water uptake with higher calcium concentrations lowering the water uptake at all temperatures studied. _Calcium uptake does not appear to be a function of temperature between 60 to 80°C but is at 90°C where a significant increase occurs. At 60, 70, and 80°C soak, water uptake decreases with increasing temperature at all soak calcium levels. At 90°C soak the water uptake is greater for the 0 ppm soak level, where it is slightly greater than the 60°C soak. The water uptake for the 90°C soak; decreases proportionately ‘with increasing calcium levels. The rates of water uptake are highest with ~the lowest soak temperature for all soak calcium concentrations tested. LIST OF REFERENCES REFERENCES Abbott, J.A. 1973. Sensory assessment of textural attributes of foods. In ”Texture Measurements of Foods," p.17. D. Reidel Pub. Co., Washington D.C.. Antunes, P.L. and Sgarbieri,V.C. 1979. Influence of time and conditions of storage on technological and nutritional properties of a dry bean (Phaseolus vulgaris) variety Rosinha. J. Food Sci. 44:1703. Anzaldua-Morales,A. and Brennan, J.C. 1982. Relationship between the physical properties of dried beans and their textural characteristics after processing. J. Texture Studies 13:229. Augustin, J., Beck, C.B., Kalbfleish, G., Kagel, L.C. and Matthews, R.H. 1981. Variation in the vitamin and mineral content of raw and cooked commercial Phaseolus vulgaris classes. J. Food Sci. 46:1701. Aw, T.L. and Swanson, B.G. 1985. Influence of tannins on {Ehafigglna;ynlga;1§ protein digestibility and quality. J. Food Sci. 50:67. Binder, L.J. and Rockland, L.B. 1964. Use of the automatic recording shear press in cooking studies of large dry lima beans (Phaseolus lunatus). Food Technol. 18:1071. Bourne, M.C. 1966. Measurement of food texture by a universal testing machine. Food Technol. 20(4):170. Bourne, M.C., Moyer, J.C. and Hand, D.B. 1966. Measurement of food texture by a universal testing machine. Food Technol. 20:522. Bourne, M.C. 1967. Size, density and hardshell in dry beans. Food Technol. 21:335. Bourne, M.C. 1972. Texture measurement of individual cooked beans by the puncture test. J. Food Sci. 37:751. 163 164 Bourne, M.C. 1976. Texture of fruits and vegetables. In "Rheology and Texture in Food Quality," J.M. deMann, P.W. Voisey, V.F. Rasper, and D.W. Stanley, (ed.) p. 275. AVI Publishing Co., Westport, CT. Bourne, M.C. 1983. Physical properties and structure of horticultural crops. In "Physical Properties of Food," M. Peleg and E.B. Bagley, (ed.), p. 207. AVI Publishing Co., Westport, CT. Brandt, M.A., Skinner, E.B., and Coleman, J.A. 1963. Texture profile method. J. Food Sci. 28:404. Bressani, R., Elias, L.G. and Navarette, D.A. 1961. Nutritive value of Central American beans. The essential amino acid content of samples of black beans, red beans, rice beans and cowpeas of Guatemala. J. Food Sci. 26:525. Bressani, R., Elias, L.G. and Braham, J.E. 1982. Reduction of digestibility of legume proteins by tannins. J. Plant Foods 4:43. Bukovac, M.J., Rasmussen, H.P., and Shull, V.E. 1981. The cuticle: Surface structure and function. Scanning Electron Microsc., III:213. Burr, J.J. 1976. Adapting an experimental bean cooker for automatic recording. J. Food Sci. 41:218. Cain, R.F. 1950. Relation of time and temperature of blanch to tenderness. The Canner 111:10. Caul, J.F. 1957. The profile method of flavor analysis. Adv. in Food Res. 7:1. Chowdhury, K.A. and Buth, G.M. 1970. Seed coat structure and anatomy of Indian pulses. In “New Research in Plant Anatomy," N.K.D. Robson, D.F. Cutler and M. Gregory, (ed.), Academic Press, New York. Corner, E.J.H. 1951. The leguminous seed. Phytomorph. 1:117. Crafts, A.F. 1944. Cellular changes in certain fruits and vegetables during blanching and dehydration. Food Res. 9:442. Daoud, H.N., Luh, B.S. and MIller, M.W. 1977. Effect of blanching, EDTA and NaHSO on color and vitamin B retention on canned garbanzo beans. J. Food Sci. 42:375. 165 Davis, D.R. and Cockrell, C.W. 1976. Effect of added calcium chloride on the quality of canned dried lima beans. Arkansas Farm Research, 25(4):14. Davis, D.R. 1976. Effect of blanching methods and processes on quality of canned dried beans. Food Product Development 10(7):?4. Davis, D.R., Twogood, M.L., and Black, K.R. 1980. Effect of blanch treatment on quality attributes of canned dry pinto and small and large lima beans. J. Food Sci. 45:817. Dawson, E.H., Lamb, J.C., Toepfer, E.W. and Warren, H.W. 1952. Development of rapid methods of soaking and cooking dry beans. Technical Bulletin No. 1051, U.S. Dept. of Ag. Wash.,D.C. Decker, R.W., Yeatman, J.N., Kramer, A., and Sidwell, A.F. 1957. Modifications of the shear press for electrical indicating and recording. Food Technol., 11:343. Dos Santos Garruti, R and Bourne, M.C. 1985. Effect of storage conditions of dry bean seeds (Phaseolus ynlgaris L.) on texture profile paramaters after cooking. J. Food Sci. 50:1067. Drake, S.R. and Kinman, B.K. 1984. Canned dry bean quality as influenced by high temperature short time (HTST) steam blanching. J. Food Sci. 49:1318. Elbert, E.M. 1961. Temperature effect on reconstitution of small white beans. Fifth Annual Dry Bean Res. Conf., USDA. Fleming, 8.3. 1981. A study of relationships between flatus potential and carbohydrate distribution in legume seeds. J. Food Sci. 46:794. Fordham, J.R., Wells, C.B., and Chen, L.H. 1975. Sprouting of seeds and nutrient composition of seeds and sprouts. J. Food Sci. 40:552. Friedman, K.R., Whitney, J.E. and Szczesniak, A.S. 1963. The texturometer - A new instrument for objective texture measurement. J. Food Sci. 28:390. Gloyer, W.O. 1921. Sclerema and hard shell, two types of hardness of the bean. Assoc. Off. Seed Anal. No. Amer. Proc. 13:60. Greenwood, M.L. 1935. Pinto beans: their preparation and palatability. N. Mex. Agr. Expt. Sta. Bull. 231. 166 Hamly, D.B., 1932. Softening of the seeds of Melilotus alba. Bot. Gaz. 93:345. Hindman, H. and Burr, G.S. 1949. The Instron tensile tester. Trans. Am. Soc. Mech. Eng. 71:789. Hoff, J.E. and Nelson, P.E. 1965. An investigation of accelerated water uptake in dry pea beans. Indiana Agric. Expt. Sta. Res Prog. Rpt. 211. Hoff, J.E. and Nelson, P.E. 1966. Methods for accelerating the processing of dry beans. Eighth Dry Bean Research Conf. Bellair, MI. Aug. 11-13. Hoff, J.E. and Nelson, P.E. 1967. Methods for accelerating the processing of dry beans. USARS 74-41:39. Hosfield, G.L. and Uebersax, M.A. 1980. Variability in physico—chemical properties and nutritional components of tropical and domestic dry bean germplasm. J. Amer. Soc. Hort. Sci. 105(2):246. Hosfield, G.L., Uebersax, M.A., and Isleib, T.G. 1984. Seasonal and genotypic effects on yield and physico- chemical seed characteristics related to food quality in dry, edible beans. J. Amer. Soc. Hort. Sci. 109(2):182. Hsu, K.H. 1983. A diffusion model with a concentration dependent diffusion coefficient for describing water movement in legumes during soaking. J. Food Sci. 48:618. Jackson, G.M. and Varriano-Marston, E. 1981. Hard-to-cook phenomenon in beans: effects of accelerated stroage on water absorption and cooking time. J. Food Sci. 46:799. Jones, P.M.B. and Boulter, D. 1983. The cause of reduced cooking rate in Phaseolus vulgaris following adverse storage conditions. J. Food Sci. 48:623. Junek, J.J., Sistrunk, W.A. and Neely, M.B. 1980. Influence of processing methodology on quality attributes of canned dry beans. J. Food Sci. 45:821. Kilgore, S.M. and Sistrunk, W.A. 1981. Effects of soaking treatments and cooking upon selected B-vitamins and the quality of blackeyed peas. J. Food Sci. 46:909. Koehler, H.H. and Burke D.W. 1981. Nutrient composition, sensory characteristics, and texture measurements of seven cultivars of dry beans. J. Amer. Soc. Hort. Sci. 106(3):313. 167 Kon, S. 1968. Pectic substances of dry beans and their possible correlation with cooking time. J. Food Sci. 33:437. Kon, S. 1979. Effect of soaking temperature on cooking and nutritional quality of beans. J. Food Sci. 44(5):1329. Korban, S.S., Coyne, D.P. and Weihing, J.L. 1981. Rate of water uptake and sites of water entry in seeds of different cultivars of dry bean. Science 16:545. Kramer, A., Burkhardt, G.J. and Rogers, H.P. 1951. The shear press, a device for measuring food quality. Canner 112, No.5, 34. Kramer, A. 1963. Revised tables for determining significant differences. Food Technol., 17(12):124. Kumer, K.G., Venkataraman, L.V., Jaya, T.V. and Krishnamurthy, K.S. 1978. Cooking characteristics of some germinated legumrs: changes in phytins, Ca++, Mg++ and pectins. J. Food Sci. 43:85. Kyle, J.H. and Randall, T.E. 1963. A new concept of the hard seed character in Phasegln§_xnlgari§ L. and its use in breeding and inheritance studies. Amer. Soc. Hort. Sci. 83:461. Loh, J., Breene, W.M. and Davis, E.A. 1982. Between species differences in fracturability loss: Microscopic and chemical comparison of potato and Chinese waterchestnut. J. Text. Studies 13, 325. Lu, C.L., Hsu, K.H. and Wilson, L.A. 1984. Quality attributes and retention of selected B-vitamins of canned Faba bean as affected by soaking treatments. J. Food Sci. 49:1053. Luh, B.S., Wang, C. and Daoud, H.N. 1975. Several factors affecting color, texture, and drained weight of canned dry lima beans. J. Food Sci. 40:557. Mattson, S. 1946. The cookability of yellow peas. Acta. Agr. Suecana II 2:185. McEwen, T.J., Dronzek, B.L. and Bushuk, W. 1974. A scanning electron microscope study of faba bean seed. Cereal Chem. 51:750. Mecredy, J.M., Sonnemann, J.C. and Lehmann, S.J. 1974. Sensory profiling of beer by a modified QDA method. Food Technol. 28(11):36. 168 Meiners, C.R., Derise, N.L., Lau, H.C., Ritchey, S.J., and Murphy, E.W. 1976a. Proximate composition and yield of raw and cooked mature dry legumes. J. Agric. Food Chem. 24(6):1122. Meiners, C.R., Derise, N.L., Lau, R.C., Crews, M.C., Ritchey, S.J., and Murphy, E.W. 1976b. The content of nine mineral elements in raw and cooked mature dry legumes. J. Agric. Food Chem. 24(6):1126. Molina, M.R., DeLaFuente, G. and Bressani, R. 1975. Interrelationships between storage, soaking time, cooking time, nutritive value and other characteristics of the black bean (Phaseolus vulgaris). J. Food Sci, 40:587. Molina, M.R., Baten, M.A., Gomez-Brenes, R.A., King, K.W. and Bressani, R. 1976. Heat treatments: A process to control the development of the hard-to-cook phenomenon in black beans (Phaseolus vulgaris). J. Food Sci. 41:661. Morris, H.J., Olson, R.L., and Bean, R.C. 1950. Processing quality of varieties and strains of dry beans. Food Technol. 4:347. Morris, H.J. and Wood, 1956. Influence of moisture content on keeping quality of dry beans. Food Technol. 10:225. Morris, H.J. and Seifert, R.M. 1961. Constituents and treatments affecting cooking of dry beans. Proceedings of the 5th Dry Bean Research Conference. USDA Agr. Es. Service. p. 42. Morris, H.J. 1963. Cooking quality of dry beans. Sixth Annual Dry Bean Conf. Jan.2-4, Los Angeles, CA. Moscoso, W., Bourne, M.C. and Hood, L.F. 1984. Relationships bewteen the hard-to-cook phenomenon in red kidney beans and water absorption, puncture force, pectin, phytic acid, and minerals. J. Food Sci. 49:1577. Muller, F.M. 1967. Cooking quality of pulses. J. Sci. Fd. Agric. 18:292. Muneta, P. 1964. The cooking time of dry beans after extended storage. Food Technol. 18:1240. Naivikul, O. and D'Appolonia, B.L. 1979. Carbohydrates of legume flours compared with wheat flour. II. Starch. Cereal Chem. 56:24. 169 Nordstrom, G.L. and Sistrunk, W.A. 1977. Effect of type of bean, moisture level, blanch treatment and storage time on quality attributes and nutritional value of canned dry beans. J. Food Sci. 42:795. Nordstrom, G.L. and Sistrunk, W.A. 1979. Effect of type of , bean, moisture level, blanch treatment and storage time on quality attributes and nutrient content of canned dry beans. J. Food Sci. 44:392. Northern, H.T. 1958. “Introductory Plant Science". p. 35. Second Edition. Ronald Press Co., New York. Ott, A.C. and Ball, C.D. 1943. Some components of the seed coats of the common bean, (Phaseolus vulgaris) and their relation to water retention. Arch. Biochem. 3:189. Powrie, W.D., Adams, M.W., and Pflug, I.J. 1960. Chemical, anatomical, and histochemical studies on the navy bean seed. Agronomy J. 52:163. Quast, D.C. and DaSilva, S.D. 1977a. Temperature dependence of the cooking rate of dry legumes. J. Food Sci. 42:370. Quast, D.C. and DaSilva, S.D. 1977b. Temperature dependence of hydration rate and effect of hydration on the cooking rate of dry legumes. J. Food Sci. 42:1299. Quenzer, N.M., Huffman, V.L. and Burnes, E.E. 1978. Some factors affecting pinto bean quality. J. Food Sci. 43:1059. Reddy, N.R. and Salunkhe, D.K. 1980. Changes in oligosaccharides during germination and cooking of black gram and fermentation of black gram/rice blend. Cereal Chem. 57(5):356. Reddy, N.R., Pierson, M.D., Sathe, S.R. and Salunkhe, D.K. 1984. Chemical, nutritional, and physiological aspects of dry bean carbohydrates - a review. Food Chem. 13:25. Reeve, R.M. 1947. Relation of histological characteristics to texture in seed coats of peas. Food Res. 12:10. Rockland, L.B. 1963. Chemical and physical changes associated with processing of large dry lima beans. Proceedings of the Sixth Annual Dry Bean Conference, Jan. 2-4, Los Angeles, CA, p.9. Rockland, L.B. and Metzler, E.A. 1967. Quick-cooking lima and other dry beans. Food Technol. 21(3):344. 170 Rockland, L.B., Wolf, W.R., Hahn, D.M., and Young, R. 1979. Estimated zinc and copper in raw and cooked legumes: An interlaboratory study of atomic absorption and x-ray fluorescence spectroscopy. J. Food Sci. 44:1711. Rockland, L.B., Zaragosa, E.M. and Oracca-Tetteh, R. 1979. Quick cooking winged beans (Psophocarpus tetragonolobus). J. Food Sci. 44:1004. Saio, K. 1976. Soybeans resistant to water absorption. Cereal Foods World, 21:168. Salunkhe, D.K. and Pollard, L.H. 1955. A rapid and simple method to determine the maturity and quality of Lima beans. Food Technol. 9:45. Sathe, S.K. and Salunkhe, D.K. 1981. Studies on trypsin and chymotrypsin inhibitory activities, hemagglutinating activity, and sugars in the Great Northern beans (Ehaggglnfi_gulga;1§ L.). J. Food Sci. 46:626. Sefa- Dedeh, S. Stanley, D. W. and Voisey, P. W. 1978. Effect of soaking time and cooking conditions on texture and microstructure of cowpeas (Vigna_nngnignlata). J. Food Sci. 43: 1832. Sefa-Dedeh, S. and Stanley, D.W. 1979a. Microstructure of cowpea variety Adua Ayera. Cereal Chem. 56:367. Sefa-Dedeh, S. and Stanley, D.W. 1979b. The relationship of microstructure of cowpeas to water absorption and dehulling properties, Cereal Chem. 56:379. Sefa-Dedeh, S. and Stanley, D.W. 19790. Textural implications of the microstructure of legumes. Food Technol. 33(10):77. Sevilla, U.L. and Luh, B.S. 1974. Several factors influencing color and texture of canned red kidney beans. Proc. IV Int. Congress Food Sci. and Technol. I:130. Shehata, A.M.E., Abu-Bakr, T.M. and El-Shimi, N.M. 1983. Phytate, phosphorus and calcium contents of mature seeds of 2111a_£aba L. and their relation to texture of pressure-cooked faba beans. J. Food Proc. Pres. 7:185. Silva, C.A.B., Bates, R.P., and Deng, J.C. 1981a. Influence of soaking and cooking upon the softening and eating quality of black beans (Phaseolus vulgaris). J. Food Sci. 46:1716. 171 Silva, C.A.B., Bates, R.P., and Deng, J.C. 1981b. Influence of pro—soaking on black bean cooking kinetics. J. Food Sci. 46:1721. Snyder, 3.3. 1936. Some factors affecting the cooking quality of the pea and great northern types of dry beans. Nebraska Agric. Expt. Sta. Res. Bull. 85. Stone, H., Sidel, J., Oliver, 8., Woolsey, A., and Singleton, R.C. 1974. Sensory evaluation by quantitative descriptive analysis. Food Technol. 28:24. Swanson, B.G., Huges, J.S., and Rasmussen, H.P. Seed microstructure:Review of water imbibition in legumes. Food Microstructure (in press). Szczesniak, A.S. 1963. Classification of textural characteristics. J. Food Sci. 28:385. Szczesniak, A.S., Brandt, M.A. and Friedmann, H.H. 1963. Development of standard rating scales for mechanical parameters of texture and correlation between the objective and the sensory methods of texture evaluation. J. Food Sci. 28:397. Szczesniak, A.S., Humbaugh, P.R., and Block, H.W. 1970. Behavior of different foods in the standard shear compression cell of the shear press and the effect of sample weight on peak area and maximum force. J. Texture Studies, 1:356. Thorne, J.H. 1981. Morphology and ultrastructure of maternal seed tissues of soybean in relation to the import of photosynthate. Plant Physiol. 67:1016. Tobin, G. and Carpenter, K.J. 1978. The nutritional value of the dry bean (£haseglus_1nlga;1§): A literature review. Nutr. Abstr. and Rev. 48(11):919. Uebersax, M.A. and Bedford, C.L. 1980. Navy bean processing: Effect of storage and soaking methods on quality of canned beans. Mich. State Univ. Agr. Exp. Sta., E. Lansing, MI. Res. Rpt. 410. VanBuren, J.F., 1968. Adding calcium to snap beans at different stages in processing. Calcium uptake and texture of the canned product. Food Technol. 22:790. VanBuren, J.F. 1979. The chemistry of texture in fruits and vegetables. J. Texture Studies 10:1. VanBuren, J.F. 1980. Calcium binding to snap bean water insoluble solids calcium and sodium concentrates. J. Food Sci. 45:752. 172 VanBuren, J.P. 1984. Effects of salts added after cooking on the texture of canned snap beans. J. Food Sci. 49:910. VanBuren, J., Bourne, M., Downing, D., Queale, D., Chase, E. and Comstock, S. 1986. Processing factors influencing splitting and other quality characteristics of canned kidney beans. J. Food Sci. 51:1228. Varriano-Marston, E. and DeOmana, E. 1979. Effects of sodium salt solutions on the chemical composition and morphology of black beans (Phaseolus vulgaris). J. Food Sci. 44:531. Voisey, P.W. and Larmond, E. 1971. Texture of baked beans - A comparison of several methods of measurment. J. Texture Studies 2:96. Voisey, P.W. 1971a. Systems for the measurement of food texture. Eng. Specif. 6930 Eng. Res. Service, Canada Dept, of Ag. Voisey, P.W. 1971b. The Ottawa texture measuring system. Engineering Res. Serv., No. 237, Can. Inst. Food Technol. J. Vol. 4, No. 3. Voisey, P.W. and Nonnecke, T.L. 1972. Measurement of pea tenderness. Development and evaluation of the test cell. J. Text. Studies, 3:459. Voisey, P.W. 1973. Some measurements of baked bean texture. Eng. Res. Service Rpt. 7222. Agriculture Canada, Ottawa, Ontario. Voisey, P.W. 1974, Readout stability of the Ottawa pea tenderometer. Eng. Res. Serv., Agr. Can. Ottawa Rept. 6820-9. Voisey, P.W. and Deman, J.M. 1976. Applications of instruments for measuring texture. In "Rheology and Texture in Food Quality," J.M. deMan, P.W. Voisey, V.F. Rasper and D.W. Stanley, (ed.) p. 142. AVI Publishing Co., Westport, CT. Voisey, P.W. 1977. Interpretation of force-deformation curves from the shear-compression cell. J. Texture Studies. 8:19. VonMollendroff, A.W. and Priestley, R.J. 1979. Aspects of the hard-to-cook phenomenon in dry beans. 19th Supplement to South African Food Rev. 173 Walker, W.M. and Hymowitz, T. 1972. Simple correlations between certain mineral and organic components of common beans, peanuts, and cowpeas. Commun. Soil Sci. and Plant Anal. 3(6):505. Warner, K.F. 1928. Progress report of the mechanical test for tenderness of meat. Ann. Proc. Am. Soc. Animal Prod. 114. Watt, B.K. and Merrill, A. 1963. Composition of Foods: Raw, Processed, Prepared. Agric. Handbook No. 8 (Revised), U.S. Dept. Agri., Washington, D.C. Wilson, J.G., Uebersax, M.A., Hosfield, G.L. and Varner, G.V. 1986. Processing quality evaluation of dry beans:1985 variety performance trials. MI Dry Bean Digest, 10(3):7. "I11111111111“