‘ c‘ u r . ‘ IHA'I‘Vxl: \'L\: , .N‘ 'm 0‘ ’ 1n' n gt, ‘V .‘I. q‘ > H n .. I . ' v ‘ . ‘ V "u‘ 1‘3: . .. ‘ y, /, ... - .. .u v - ~ '5. ”4“" ' , . 4 | ,. “gm.“ '4 - 4.“..Ai.‘ “. . . ' ‘.'_ '57: L I tr . . " _ p" f; ‘- v V p L‘. - I ' " I. 1‘ ‘ ' ‘ ‘ ‘;:‘ ' HM: ‘ ‘ - ‘ Huh} 9' H'v: ’ ' v“. 3&6 ‘ 1"." ". ",1...\"VI‘ .lv ‘ > ‘ ‘ , . 4 , I‘v‘ «‘6' 3’ n 9 ‘ 1‘ ‘v “1}: n I I: 1 v (7:; ' 3:0“ , .-.,_, ‘1‘. ”'1” 72;; :1. «'4'. ‘.‘ .\ {win‘ ‘ . W . W K.“ WV?“ Li: J I l I “VF-4 M h m u ' ‘ ("W ',‘.n.‘. ‘ '1 ‘H. ‘. .‘..:."k:L-‘.I‘ “Inl‘ w This is to certify that the thesis entitled CARROT CHIP DEVELOPMENT AND OTHER SOURCES OF'DIETARY FIBER presented by Wen-Li John quang has been accepted towards fulfillment of the requirements for J. 5. degree in Y-oads 72,2114 " Kat/é; k’ (gajor profgor Date 6/9/78 0-7639 © 1978 WEN-Ll JOHN JWUANG ALL RI GHTS RESERVED CARROT CHIP DEVELOPMENT AND OTHER SOURCES OF DIETARY FIBER By Wen-Li John quang A THESIS Submitted to Michigan State University in partial fulfillment of the requirement for the degree of MASTER OF SCIENCE Department of Food Science and Human Nutrition 1978 ABSTRACT CARROT CHIP DEVELOPMENT AND OTHER SOURCES OF DIETARY FIBER By Wen—Li John quang Carrot chips were prepared from a modified spicy wheat chip formulation, substituting 0 to 40% carrot powder and/or a combination of 12 to 26% carrot powder with 4 to 8% commercial cellulose for wheat flour, to study the feasibility of producing a high vegetable fiber snack. Incorporation of carrot powder and cellulose into the carrot chip formulation improved color, texture, and flavor quality characteristics. All carrot chips were scored higher than the control wheat chips. Enzymatic Neutral Detergent Fiber Analysis of more than fifty items indicated that good dietary fiber sources could be obtained from products containing vegetables, fruits, cereals, cereal brans, nuts, plant seeds, and com- mercial celluloses. Substitution with carrot powder up to 40% and cellulose up to 8% produced carrot chips with 7.43 and 12.58% Enzymatic Neutral Detergent Fiber respectively. All bran, bran buds, Tortilla chips, and Swedish rye crisp- bread all contained over 30% Enzymatic Neutral Detergent Fiber. ACKNOWLEDGEMENTS I wish to express my sincere gratitude to my major professor, Dr. Mary Ellen Zabik, for her guidance and assis- tance throughout my Master's program and the preparation of this manuscript. I wish to extend my thanks to Dr. Wanda Chenoweth and Mrs. Ann Mellen for their technical help in ENDF Analyses as well as for use of their laboratory facilities. Special thanks also are extended to Dr. J.N. Cash, Dr. L.E. Dawson, Dr. M.R. Bennink, Dr. T. Wishnetsky, Mrs. Carol M. Weaver, Mrs. M.A. Nicholas, Mrs. Kristen Uebersax, and Mr. Mark McLellan, for their technical help, material donation as well as use of other laboratory facili- ties. Many thanks are extended to the members of my graduate committee; Dr. Everett H. Everson, Dr. Karen Morgan, and Dr. Wanda Chenoweth, for their review and approval of my Master's thesis and program. Thanks also to Miss Diane Vratanina and Mrs. Mary Van Eck for their kind help in English grammar. Thanks is also extended to all my taste panelists for their enthusiastic cooperation in doing the sensory quality evaluation. 11 My great gratitude is expressed to my parents and my brothers, sisters for their encouragement and loving sup- port. My special thanks is extended to my sponsor, the Missionaries of the Divine Words Society at Fu Jen Univer- sity, Taiwan, for their constant encouragement and financial support which made it possible for me to obtain a Master degree at Michigan State University. Finally, a great deal of appreciation to my religious community, the Missionary Sisters of the Servants of the Holy Spirit, for their constant loves and prayers in supporting my studies. iii TABLE OF CONTENTS LIST OF TABLES. LIST OF FIGURES INTRODUCTION. REVIEW OF LITERATURE. . . Nature of Dietary Fiber. . . Structural Materials of the Plant Cell-. Halls. . . . . . . . . Chemistry of the Dietary Fiber . . . . Physical Properties of Dietary Fiber . Nater- Holding Capacity . . . . . Ion- Exchange Capacity. . The Role of Dietary Fiber in Human Nutrition Dietary Fiber and Colon Function Effect of Stool Weight Effect on Transit- Time . . Dietary Fiber and Gastrointestinal Dis- ease . . . . Diverticular Diseases. Colonic Cancer . Constipation Appendicitis Hiatus Hernia. . . Dietary Fiber and Lipid Metabolism . Side Effects of Dietary Fiber. Suggestions for Recommended Daily Allowances . . . . . . Analyses of Dietary Fiber. . . . . Sources of Dietary Fiber . . Use of Dietary Fiber in Food Systems Formation of Snack Chip Structure. EXPERIMENTAL PROCEDURE. . . . Food Material and Chemical Procurement Carrot Chip Formulation. . . Preparation of Dehydrated Carrot Powder. Carrot Chip Preparation. . . . Objective Measurement. Moisture iv Page vi ix Color. Crispness. . . Subjective Evaluations . Home- Made Whole Grain and Fruit Type Breads. Home- Made Bread Preparation. . . Material Preparation Methods and Procedures . . Dietary Fiber Sources in Commercial Baked. Products Determination of Enzymatic Neutral Detergent Fiber. . . Solution Preparation . . . . Neutral Detergent Solution . Enzyme solution. Extraction Procedure Analyses of Data RESULTS AND DISCUSSION Carrot Chips Moisture . Color. . . Crispness, Friability and Shear Press. Mouthfeel and Flavor . General Acceptability. . Enzymatic Neutral Detergent Fiber (ENDF) Values . . Dietary Fiber Available From Commercial and Home- made Foods. SUMMARY AND CONCLUSIONS. PROPOSALS FOR FUTURE STUDIES APPENDIX REFERENCES CITED . . . . . . . . . . 103 Table 10 ll 12 l3 14 LIST OF TABLES Components of dietary fiber. The chemistry of the major components of the plant cell-walls . . . . . Water-holding capacity of acetone dried food stuffs. . . . . . Water-holding capacity of food fiber Cation-exchange capacity of acetone dried powder . . . . . . . . . . Approximate dietary fiber content of some common food stuffs . . Comparison of neutral detergent fiber and crude fiber value in selected foods. Comparative fiber data from crude fiber and neutral detergent fiber analysis Proximate analyses of various agricultural products . . . . . . . . . . . . Proximate analyses of cereal brans Total composition of dietary fiber in some fruits and vegetables. . . . . . . . The total dietary fiber and its composition in some wheat products . . . . . Crude fiber and calorie content of cereals, roots, tubes and seeds Crude fiber and calorie content of vegeta- bles, fruits and seaweeds. . . vi Page 15 T6 19 3O 3O 31 32 33 34 35 37 38 Table l5 16 17 18 19 20 21 22 23 24 25 26 27 28 29 3O 31 32 Formulation for Chinese sweet wheat chips. Formulation of control wheat chip and eight spicy carrot chip variables. Formula for fig-bran bread Formula for banana-bran bread. Formula for bran bread with molasses Formula for zucchini (or carrot) bread Formula for rye bread. Formula for raisin—nut rolled oat bread. Formula for rolled oat nut bread Formula for apple bread. Formula for raisin bread Commercial grain-based products of dietary fiber source . . . . . . Means and standard deviations for moisture determination of carrot chips. Analyses of variance for objective evalu~ ations of carrot chips prepared with substitutions of carrot powder and/or cellulose. . . . . . . . . . . . . . Means and standard deviations for both subjective and objective color values of carrot chips . . Analyses of variance for subjective evalu- ations of carrot chips prepared with sub- stitutions of carrot powder and/or cellulose. . . . . . . . Means and standard deviations for texture and shear press value of carrot chips. Means and standard deviations for flavor and mouthfeel of carrot chips. Page 54 55 63 63 64 64 65 65 66 66 67 7O 76 77 79 80 82 84 ' Table 33 34 35 36 37 Means and standard deviations for general acceptability of carrot chips. . Means and standard deviations for Enzy- matic Neutral Detergent Fiber (ENDF) Analyses of carrot chips . . . . . Analysis of variance for Neutral Deter— gent Fiber (ENDF) values of carrot chips prepared with carrot powder and/or cellulose. . . . . . . . . . . . . Means and standard deviations for Enzy- matic Neutral Detergent Fiber content in cereals and whole grain breads Means and standard deviations for Enzy- matic Neutral Detergent Fiber content in crackers, European flatbreads, cookies, snacks and other food stuffs viii Page 86 88 88 91 92 LIST OF FIGURES Figure Page 1 The layers of the cell-walls of cellulose fibers. . . . . . . . . . . . . . . . . . . 6 2 The structure of the plant cell-wall and its major component distribution. Arrow shows the increasing amount of the distri- bution. . . . . . . . . . . . . . . . . . . 6 3 Cutting diagram for square-shaped raw carrot chip dough . . . . . . . . . . . . . 58 4 Cutting diagram for diamond-shaped raw carrot chip dough . . . . . . . . . . . . . 59 ix INTRODUCTION Whether increasing the amount of dietary fiber in our diet is beneficial is still controversial. Fiber advocates believe that an optimum amount of dietary fiber can prevent gastrointestinal diseases such as constipation (Burkitt et al., l972), diverticulitis (Painter and Burkitt, l97l), bowel polyps, colonic cancer (Burkitt, l974), and appendi- citis (Burkitt, l97l, Walker et al., 1973). Ischaemic heart disease (Trowell, 1972), obesity (Walker, l964), and gallstones (Burkitt et al., 1974) are also possibly related to a dietary fiber deficiency. Dietary fiber functions primarily as bulking and cation-exchanging agents and thereby it promotes bowel function regularity, shortens intestinal transit time, and may prevent gastrointestinal diseases. Eating a high fiber diet can have some side effects, such as a feeling of being "stuffed" or "bloated" (Harlan, 1977). Since fibers have ionic exchange capacities, large amounts can impair the body's ability to absorb certain important nutrients such as iron, copper, and calcium (Eastwood, l977). Although much more research is needed before the full role of dietary fiber in human diets is known, low fiber consumption may be related to the higher incidence of gastrointestinal diseases. Scientists, how- ever, have not yet determined how much fiber one should consume. Currently there is no Recommended Daily Allowance for fiber. Current studies on the role of dietary fiber reveal that both the source and the amount of dietary fiber have changed during the last century (Friend, l967). A marked reduction in consumption of cereals has occurred in Western diets during the past century. Along with this reduction, an increased amount of animal products, highly refined cereals, and sweet foods have been consumed (Burkitt, 1973). To introduce fiber back into the American diet, con- sumption of such foods as vegetables, cereals, cereal brans, bean hulls, nut skins, plant seeds, seaweeds, plant exudates, commercial cellulose, and synthetic gums will have to increase. It is also possible to increase the level of dietary fiber in foods commonly consumed but increasing the level of dietary fiber in a food system may have a significant effect on the quality characteristics of a product. Food researchers have increased the amount of dietary fiber in various food products with dietary fibers. Several research papers indicated that various bakery products are feasible fiber carriers, i.e., bread (Tsen, l975; Lorenz,l976; Pomeranz et al., l976; Khan et al., l976; Prentice and D'Appolonia, l977; Casey and Lorenz, l977; and Volpe and Lehmann, 1977), Cake (Rajchal et al., 1975; Brockmole and Zabik, 1976; Zabik, et al., 1977; Shafer and Zabik, 1978), biscuits (Brys and Zabik, 1976) and sugar-snap cookies (Khan et al., 1976; Casey et al., 1977; and Vratanina, 1978). The purpose of this research was to evaluate several foods for their dietary fiber content. Cereal grains, vegetables and fruit were thought to have potential as dietary fiber sources, therefore selected commercial cereals and whole grain flatbreads, crackers, cookies and snack foods as well as homemade bakery products were analyzed for dietary fiber. This research also developed a spicy carrot snack food using carrot powder and cellulose to increase the fiber content of a modified oriental spicy wheat chip to provide another choice for consumers should they want to increase their dietary fiber consumption. REVIEW OF LITERATURE Nature of Dietary Fiber Cummings (1976) summarized the different professional viewpoints of fiber. To the cereal chemist, fiber is cel- lulose. To the animal nutritionist, it is the insoluble matter indigestible by animal enzymes while the human nutritionist considers fiber to be the unavailable carbo- hydrates and lignin. Trowell (1974) defined dietary fiber as the remnants of the plant cell-walls that are not hydro- lyzed by the alimentary enzymes in the human body. All dietary fibers, except lignin, are complex poly- saccharides which behave as structural units in the plant. The major components of the plant cell-walls are cellulose, hemicellulose, lignins, pectin substances, and traces of gums and mucilages; these are present in varying degrees in all plants and natural plant products (Table 1). Structural Materials of the Plant Cell-Walls The plant cell-walls are made of a number of discrete layers, and the relative size and composition of these layers change as the cell matures (Reese, 1963). The first stage in the formation of a new cell-wall is the appearance of the cell-plate which is characteristically rich in pectic substances. This extends until it meets the existing 4 Table 1. Principal sources in the diet Structural materials of the plant cell- walls Non-structural materials either found naturally or used as food additives Components of dietary fiber 1 Description Structural poly- saccharides Non-carbohydrates constituents Polysaccharides from variety of sources Classical nomenclature — *— Pectic substances Hemicellulose Cellulose Lignin and mineral compo- nents Pectic substances Gums Mucilages Algal polysac- charides Chemically modi- fied polysac- charides 1Southgate (1976) walls and becomes the middle lamella. The secondary cell- wall, also is made up of a number of distinct layers. In these layers the cellulose fibrils lie parallel to one another at an angle to the axis of the cell. The matrix is composed of hemicelluloses; the proportion of cellulose in the secondary cell-wall may be of the order of 20 per cent. In the successive layers of the secondary cell-wall the angle of the fibrils to the axis tends to become less acute (Figure 1). As the cell matures lignin is deposited in the matrix, the process of lignification starts in the middle lamella and continues toward the inside of the cell. Lignification seems to involve infiltration of the matrix with lignin rather than replacement of the hemicellulose (Figure 2). Middle Lamella (A) Primary Cell-Wall (B) Outer Secondary Cell-Wall (C) Middle Secondary Cell—Wall (0) Inner Secondary Cell-Wall (E) Figure l. The layers of the cell—walls of cellulose fibers (Reese, 1963). Middle Lamella Primary Cell-Wall Cell-Wall Lignin Pectin )Cellélose Lumen Hemic llul se Figure 2. The structure of the plant cell-wall and its major component distribution. Arrow shows the increasing amount of distribution. Crystalline cellulose is in the highest concentration near the lumen and diminishes toward the primary cell-wall. Hemicellulose predominates in the primary cell-wall and its concentration diminishes toward the lumen, making its distribution pattern opposite to that of cellulose. The rapidly growing young plant tissues have a high concentra- tion of pectic and hemicellulose, whereas the more mature tissues such as stalks, stems, and leaves have a higher lignin and cellulose content (Eastwood, 1974). Chemistry of the Dietary Fiber The chemistry of the major components of the plant cell-walls were summarized by Southgate (1976) and are pre- sented in Table 2. Pectic substances are basically polymers of 1,4-B-D- galacturonic acid. Most of the pectin heteropolysaccha- rides also contain D-galactose, L-arabinose, D-xylose, L- rhamnose, and L-fucose. The carboxyl groups of D-galac- turon acid may be partly esterified by a methyl group. These carboxyl groups also bind with cations such as calcium and magnesium to form insoluble salts. This ion-binding capacity is closely related to its free uronic acid content. Protopectin is the water-insoluble parent pectic substance that occurs in plants and which on restricted hydrolysis yields pectin. Pectic acid is the pectic substance made only from polygalacturonic acid. Pectin is a partly esteri- fied pectic acid (Cummings, 1975)‘ The chemistry of the major components of the plant Types of structure Preferred nomenclature Table 2. _fi cell-walls1 Classifi- Method of cation isolation Pectic Soluble in substances water in the presence of chelating agent Hemi- Soluble in di- cellulose luted alkali, precipitated with acid and alcohol Cellulose Insoluble in alkali but soluble in 72% w/w H2504 Lignin Insoluble in 72% w/w sul- furic acid and alkali Galacturonans, arabinans, galactans, arabinogalac- tans Mixture of heteroglycans, usually rich in xylose and containing other sugars (arabinose, galactose, mannose, and uronic acids 1.4-8-0 glucan with trace of other sugar Aromatic poly- mers based on phenyl propane units Part of non-cel- lulosic, matrix polysaccharide fraction (ideally as specific poly- saccharides) Major part of non-cellulosic matrix, polysac- charide fraction (usually as speci- fic polysaccha- rides) Cellulosic frac- tion Lignin 1Southgate (1976) Hemicellulose is made up of long chains of such mono- saccharides as xylose, galactose, glucose, mannose, and arabinose (Cummings, 1976). It is soluble in cold dilute alkali, The molecules of hemicellulose, which contain between 150 to 200 sugar units are much smaller than cel- lulose. They are also more amorphous than cellulose mole- cules, although some xylans exhibit a crystalline structure. Southgate and Durnin (1970) reported that approximately 85 per cent of hemicellulose undergoes bacterial degradation in the large bowel. The important properties of hemicellu- lose are its water-holding capacity and ion-binding capa- city, and therefore hemicellulose contributes great bulk by swelling in water. Cellulose is a linear polymer of 1-4 linked 8-D- glucopyranose residues (Aspinall, 1970). The materials exist as extremely thin long fibrils which contain a central crystalline region that is pure cellulose, but are sur- rounded by a coat of mixed polysaccharide chain of xylans and mannans. Cellulose is not hydrolyzed by human alimen- tary enzymes, and this fine network which is interwoven with hemicellulose and small amounts of partially digestible cellular' content, travels to the intestine. Southgate (1975b) assessed that approximately 15 percent of the cellulose present will undergo bacterial degradation in the large bowel. Lignin is a highly insoluble non-carbohydrate cell- wall material (Neish, 1965). It is an extremely aromatic 1O polymer of three different phenylpropane units derived from three alcohols as follows: 4-hydroxypheny1propane is derived from coumaryl al— cohol; H0 <:) H=CHCH20H Coumaryl alcohol guaiacylpropane (4-0H-3-methoxypropane) is from coniferyl alcohol; H0 (:) CH=CHCH20H H3CO Coniferyl alcohol and 3,5-dimethyl-4—OH-phenylpropane is from sinapyl alcohol. H3CO HO <:) CH=CHCH20H H3CO Sinapyl alcohol The links between the basic units are complex. Unlike other cell-wall structures, it is a small polymer having a molecular weight of between 1000 to 4500. The basic units of the polymer are joined by carbon—to-carbon bonds, unlike the glycoside and acetal links of the carbohydrates. Lig- nin's role in the cell-wall is to strengthen the other constituents. In general, wood contains up to 40 to 50 percent lignin in the cell-wall, while wheat cell-walls 11 contain 23 per cent, cabbage 6 per cent, and apple 25 per cent (Southgate, 1969). Animal nutritionists indicated that lignin impairs the digestibility of other cell-wall polysaccharides and thereby reduces the potential energy available from many common forages used in ruminant nutri- tion (Van Soest, 1973). Lignin is thought to have bile- salt-binding properties through hydrophobic interactions (Eastwood and Hamilton, 1968). Non-structural materials either found naturally or used as food additives include plant gums, mucilages, and seaweed extracts. They are usually indigestible in the human alimentary tract. Aspinall (1970) classified gums into the following five groups: Galactan Group. This includes gum arabic and the exudate gums of a number of other Acacia species. The galactans are a s-galactan linked 8(1-3) with side chains of 3(1-6) galactopyranosyl chains terminating with glu- curonyl residues. These gums undergo autohydrolysis in solution of very weak acid, leading to a loss of arabinose. Glucuronomannan Group. In the glucuronomannan group the main chain consists of alternate glucopyranosyluronic acid and mannopyronosyl residues, and the side chains are of galactosyl residues linked 8(1-6) attached to the main chain by an arabinopyronosyl group. Examples of the plant gums belonging to this group are damson and cherry gums and gum ghatti. 12 Galacturonorhamnan Group. The gums in this group contain a main chain of D-galacturonic acid and L-rhamnosyl groups. The ratio of these residues varies from gum to gum. Examples include stercularia gum and khaya gum. Xylan Group. Only a few xylan gums have been studied. Sapote gum and the polysaccharides from the corns and seed cases of Watsonia are structurally related but are more complex than the xylans which have been found as cell-wall components. Xyloglucan. Xyloglucan is the gel-forming poly- saccharide extracted from the seed of tamarind. The interi- or chain of xyloglucan resembles cellulose but the side chains vary. The detailed structure of this group has not been defined. Mucilages that are present in many seeds possess water-holding properties and are composed of acidic and neutral fractions. The acidic component contains a main chain of D-galacturonic acid and L-rhamnose. The neutral component includes galactomannans, glucomannans, arabino- xylans, and xyloarabinans. Xyloarabinans are usually closely related to acidic polymers. Seaweed gums are mainly from algal polysaccharides and include agar, alginate, carrageenan, and furcellaran (Glicksman, 1969). They are dietary fibers and are not hydrolyzed by mammalian digestive enzymes. Cellulose also occurs in many species of algae. Structural studies on many algal polysaccharides have 13 confirmed that they are usually linear B-D(l-4) mannans, and 8-D(l-4) and (l—3)-linked xylans, respectively. Alginic acid is an important algal polysaccharide used frequently as a food additive. Alginic acid is insoluble in water but readily soluble in aqueous solution of alkalimetal hydrox- ides and carbonates, and these alginate salts yield viscous solution in water. Alginates that are rich in L-guluronic acid have higher pK values. Those alginates rich in man- nuronic have higher calcium affinity in a sodium—calcium ion-exchange reaction (Southgate, 1976). Both agar and carrageenan are dietary fibers con- taining the sulfated D- and L-galactans which are extracted from algae with boiling water (Glicksman, 1969). The gel formation of the algal polysaccharides depends on the pro- portion of 3,6 anhydrogalactose residues. The gel-forming characteristics of both agar and carageenan have been widely used in the food industry; these molecules of relatively high ester sulfate composition being preferred. Carragee- nan has the ability to combine with protein to form protein- gel complexes. It is also a good thixotropic material and can be used as a suspending agent in the preparation of chocolate milk. Agar is relatively resistant to bacterial attack and is capable of holding great amounts of water, thereby increasing fecal bulk. Agar has been used as a laxative agent (Shung, 1963). Furcellaren is made from Furcellaria. It is composed mainly of D-galactose and 3,6-anhydro-D-galactose units and 14 a half sulfate ester. Furcellaren also has been used as a food additive (Glicksman, 1969). Synthetic gums commonly used in the food industry are cellulose derivatives. Since cellulose itself occurs in a highly bonded triple strand, alkyl or hydroxyalkyl groups are substituted on each anhydro-glucose unit of the cellu- lose chain. This results in disorder and causes separation of the cellulose strands so that water or other solvents may enter to solvate the chemically modified cellulose. The substitution groups such as hydroxyethyl, sodium carboxyl- methyl, methyl, ethylhydroxyethyl, and hydroxypropyl allow the formation of products with wide range of functional properties (Glicksman, 1969). Physical Properties of Dietary Fiber One of the most important properties of the plant dietary fiber is the capacity of the endogenous polysac- charides and other Inacromolecules to swell when exposed to water. Water-Holding Capacity Water-holding capacity may vary with the plant fiber sources due to the differences in the hydrophilic polysac- charide content. The water-holding capacity appears to be greatest in the vascular tissues such as roots, stems and 1ei1ves; and is less marked in storage organs as shown in) Tat>1e 3. Table 4 summarizes the fiber content and water 15 Table 3. Water-holding capacity of acetone dried food stuffs1 Water—holding capacity Acetone dried food materials (gm water/gm acetone dried powder) Maize 1.47 Oatmeal 1.82 Potatoes 2.00 Banana 2.90 Broad bean 3.00 Pea 4.10 Cauliflower 4.60 Pear 5.90 Green bean 7.40 Turnip 8.10 Winter cabbage 9.00 Tomato 9.70 Spring cabbage 10.80 Brussels sprouts 11.30 Apple 11.40 Orange 12.10 Onion 12.40 Rhubarb 13.90 Aubergine 14.50 Celery 17.30 Mango 19.20 Cucumber 20.40 Carrot 23.40 Lettuce 23.70 1McConnell et al., 1974 Table 4. Water-holding capacities of food fiber 16 1 % fiber in Water-holding Capacity of water FOOdS raw materials capacity (gm absorption in 100 water/gm gm of raw vege- fiber) tables (gm water) Turnip 4.0 9.0 37 Potato 19.5 2.0 41 Rhubarb 4.2 14.4 60 Banana 22.7 2.9 68 Cauliflower 11.6 5.9 68 Tomato 6.6 10.8 71 Broad bean 18.8 4.1 77 Cucumber 3.7 20.9 77 Celery 6.0 16.2 97 Pea 21.6 4.6 99 Lettuce 4.2 23.7 99 Green bean 12.4 8.1 100 Pear 15.3 7.4 113 Orange 9.9 12.4 122 Maize 86.1 1.5 129 Aubergine 7.5 17.3 129 Apple 14.6 12.1 177 Carrot 8.9 23.4 208 Mango 15.3 20.4 312 Bran 89.3 3.0 447 1Eastwood and Mitchell, 1976 17 holding capacity in terms of fiber content as well as fresh weight basis as described by Eastwood and Mitchell (1976). The water-holding capacity based on fiber content ranges from 5 to 6 times (gm water/gm fiber) for bran and up to 35 times (gm water/gm fiber) for lettuse, carrots, and cucumber. However, when water-holding capacity is based on total weight most raw fruits and vegetables including potatoes and turnips have the least ability to absorb water, whereas the mango, carrots and bran are most efficient in absorption of water. Ion-Exchange Capacity The acid polysaccharides of fruits and vegetables have a cation-exchange capacity. The divalent metals may be absorbed by dietary fiber to a degree dependant on the presence of unsubstituted uronic acid groupings (Walters et al., 1975). Smidsrod and Haug (1965) indicated that divalent metals such as calcium, have a great effect on gel formation and precipitation properties of sodium alginate. The ion-exchange capacities of vegetable fiber were mea- sured by titration with sodium hydroxide after conversion of the fiber to the acidic form by treatment with excess hydrochloric acid (Hofmann, 1967). Most of the vegetables act as monofunctional weak cation-exchange resins. Maize, oatmeal, banana, cereal bran, and new potatoes act as very weak polyfunctional cation-exchangers; in these, the hydro— gen ion dissociates from the uronic acid groups at different 18 pH levels in the titration curve. McConnell etal. (1974) reported the cation-exchange of acetone-dried food powders. Old potatoes, tomatoes, cucumbers, onions, celery, auber- gine, apples, turnips, carrots and spring cabbages all had a high cation exchange capacity (Table 5). Parrott and Thrall (1978) investigated the physical property differences of 12 commercial fiber sources on their particle size, density, hydrated volume expansion, water- holding capacity, and temperature. They found that each fiber has its own distinct functional properties. In most cases, dry density has a linear relationship to the hydrated density. However, in terms of pH and ionic strength, mono- and divalent cations were highly indifferent. Therefore, the individual fiber responses to processing condition should be taken into consideration when selecting a fiber source. The Role of Dietary Fiber in Human Nutrition Studies have indicated that most dietary fiber is indi- gestible in human alimentary systems. Although dietary fiber contributes little food value, it does play an impor- tant physio-chemical role in the human digestive system. Van Soest (1977) reported that dietary fiber undergoes chemi- cal changes through flora fermentation in the colon and releases volatile fatty acids with substantial caloric value. Van Soest suggested that fiber might be considered as a nutrient, despite its indigestibility, since it has beneficial effects on the body similar to those of other 19 Table 5. Cation-exchange capacity of acetone dried powder1 Cation-exchange Acetone dried food capacity mEq/gm Degree materials acetone dried powder exchange Old potato 0.3 strong Pear 0.6 medium Pea 0.8 medium Broad bean 0.9 medium Cauliflower 1.0 medium Tomato 1.0 strong Cucumber 1.1 strong Brussels sprouts 1.1 medium Onion 1.3 strong Green beans 1.4 medium Winter cabbage 1.5 medium Celery 1.5 strong Rhubarb 1.7 medium Aubergine 1.8 strong Apple 1.9 strong Turnip 2.3 strong Orange 2.4 medium Carrot 2.4 strong Spring cabbage 2.4 strong Lettuce 3.1 medium 1McConnell et al., 1974 20 nutrients Dietary Fiber and Colon Function Water soluble dietary fibers such as pectin, mucilages and pentosans (water-soluble hemicellulose) undergo microbial degradation in the colon to produce low molecular weight volatile fatty acids, water, carbon dioxide, and methane (Olmstead and Williams, 1936). These microbial metabolites and the physical presence of other indigestible dietary fibers affect intestinal function. Burkitt et a1. (1972) and Cummings (1973) indicated that dietary fiber is essential for normal bowel function by promoting regularity, soft stools, and a rapid transit-time. Effect on Stool Weight. Food materials composed of high amounts of unavailable carbohydrates have a great water- holding capacity. Also, the various dietary fiber components absorb water to different degrees. The pectic substances and hemicelluloses have a high water-holding capacity. Cellulose absorbs water moderately, while lignin is more hydrophobic, absorbing little water but is significantly active in bile acid absorption at an acid pH. In the colon, pectin absorbs a great amount of water and serves as a cementing material combining all the indigestible lignin, cellulose, hemicellulose, bile acids, and other metabolites. Thus ingesting food materials with mixed dietary fiber com- ponents enhances formation of a large amount of soft stool which fills the colon and promotes bowel movement regularity. 21 Kirwan et a1. (1974) and Brodribb and Groves (1978) reported that the particle size of wheat bran affected in vivo laxation by increasing water-holding capacity and stool weight. Brodribb and Groves (1978) reported that there was no significant difference in defecation rate between the two types of bran, but with coarse bran, stool weight was sigr nificantly greater than with fine bran. Fine bran increases the pressure within the rectum, therefore coarse rather than fine bran is preferred for prescription (Eastwood, 1977). Effect on Transit-time. Transit time is the time taken for the passage of food material from the mouth to the anus. Burkitt, et a1. (1972) postulated a logarithmic relationship between daily stool weight and transit time; the shorter transit time being related to higher stool weight. When cereal bran was ingested in combination with a normal diet, it not only caused an increase in stool weight but also a decrease in transit-time. This effect has been shown in normal subjects (Burkitt et a1. 1972; Brodribb and Groves, 1978) and also in patients with diyerticular disease (Mit~ chell and Eastwood, 1976). However, not all subjects exhibi- ted shortened transit-time when given bran (Harvey et al., 1973). Both banana and guava showed contradictory effects on laxation and constipation. This discrepancy was believed to be related to the degree of maturity of both fruits. The proportion of the various components of dietary fiber in a mixed diet is also an important factor in the determination of stool weight and transit-time. 22 Dietary Fiber and Gastrointestinal Diseases 3 Epidemiological studies have indicated that gastro- intestinal disorders are related to the low-residue of fiber-depleted diets. In the more developed countires, fiber consumption from cereal sources was greatly reduced by the introduction of new milling techniques and changes in dietary patterns. Consumption of cereals in the form of porridge has also diminished. Cereal fiber intake has probably fallen to one tenth of the pre-1870 figure. Al- though consumption of fruit and vegetable fiber has increased, these sources apparently have much less effect on bowel physiology than does cereal fiber (Hoppert and Clark, 1945). Diverticular Disease. Fiber-depleted diets may cause disease directly through the effect of lack of fiber on the bulk and consistency of stools, and the transit-time (Bur- kitt, 1976). Diverticular disease occurs as a result of hypersegmentation of the colon (Painter et al., 1975). The propulsion of the small, firm stools along the colon will result in increased pressures in the lumen of the bowel. This pressure will cause areas of weakness in the colon to bulge and thus produce small pockets or diverticulae (Bur- kitt, 1975). Segmentation and consequent pressure genera- tion may be caused by many stimuli including eating habits, mechanical or emotional disturbances and drugs such as morphine (Painter, 1975). A rapid transit-time as provided from a high fiber diet does not produce strain on the 23 sigmoid and does not favor the development of diverticula. Colonic Cancer. Prolonged transit-time of the large bowel has been thought to be related to low fiber diets (Eastwood and Mitchell, 1976). The hypothesis of Burkitt et a1. (1972) suggested that prolonged transit-time pron vides more time for bacterial proliferation and thus causes increased microbial degradation of bile acids to potential carcinogens. The degree of microbial degradation is depen- dent on the nature of the carbohydrates reaching the large bowel. Generally, mature plant fibers such as brans ferment less completely than those of vegetable cell-walls. Ligni- fication of plant material limits the microbial fermentation (Van Soest and Robertson, 1977). Thus vegetable dietary fiber yields more volatile fatty acids via fermentation than those fibers from concentrated cereal grain. The bulking effect of dietary fiber may act to dilute the carcinogen, thereby serving as a protective mechanism in the prevention of colonic cancer. Constipation. Constipation is a state of inadequate bowel motility. It is caused primarily by an insufficient bulk-forming capacity of the habitual diet (Avery Jones and Godding, 1972). Burkitt (1974) postulated that constipation and fecal stagnation may result in raised intraluminal pres— sure and prolonged exposure of the lower alimentary mucosa to carcinogenic substances in the feces. Thus, foods which enhance constipation could lead to polyps and cancer. 24 Appendicitis. Appendicitis may be related to consump- tion of a low residue diet that increases the viscosity of the feces (Walker, 1976). This causes the formation of fecaliths and excessive segmentation of the appendix which results in obstruction of the appendix lumen. The obstruc- tion can cause the intraluminal pressure to sufficiently devitalize the appendicular mucosa and thus allow bacterial invasion. Hiatus Hernia. Hiatus hernia is a protrusion of the upper end of the stomach into the thoracic cavity (Burkitt, 1976). Increased intra-abdominal pressures may contribute to the production of hiatus hernia. Burkitt (1974) emphasized epidemiological and chrono- logical data which associated bowel diseases, venous dis- orders, and hiatus hernia with obesity, diabetes mellitus, and coronary heart disease. Cleave et a1. (1969) reported that removal of fiber from carbohydrate foods apparently leads to over consumption and over absorption of the refined foods. Dietary Fiber and Lipid Metabolism Eastwood and Boyd (1967) reported that a considerable amount of bile acids bind to unabsorbable materials in the small intestine. Lignin particularly tended to be more hydrophobic in nature and actively bound bile salts at an acid pH. Story and Kritchevsky (1976) suggested that fiber inhibited cholesterol absorption by binding bile salts; 25 such absorption would increase bile acid excretion, and cause an increase in bile acid synthesis in order to replace the lost bile salts. Both events would drain cholesterol pools. Birkner and Kern (1974) studied in vitro absorption of bile salts to food residues, finding significant binding of sodium glycocholate and sodium chenodeoxycholate to hemi- celluloses from apple, celery, lettuce, potato, and string bean. Wheat fiber did not lower the plasma cholesterol in hamsters and human beings (Truswell and Key, 1975). Never- theless, rolled oats and whole ground oats were found to lower plasma cholesterol in experimental animals (Fischer and Griminger, 1967). These researchers also reported that citrus pectin and other gums have a significant effect on the reduction of plasma cholesterol in man. Truswell and Key (1975) found that methoxy pectin had a great effect on lowering cholesterol levels in the rat, especially when dietary fat was low. Leveille and Sauberlich (1966) suggested that the mechanism of the action of pectin was to inhibit cholesterol absorption and increase fecal bile acid excretion. Cellulose has not been found to lower plasma cholesterol in human experiments unless very large amounts of cellulose were fed (Prather, 1964; Eastwood et al., 1973). Forsythe et a1. (1976) reported that fiber did not decrease serum cholesterol in rats, when compared to fiber-free group. The uronic acid content of rice also reduced cholesterol levels in plasma (Truswell. 1976). 26 Side Effects of Dietary Fiber Fiber intake increases the fecal loss of certain impor- tant nutrients (Eastwood, 1977). Cereal bran as well as vegetables and fruit fiber have cation-exchange capacities which may increase the excretion of both mono- and di-valent cations such as sodium, potassium, calcium, and magnesium, in normal subjects. Fiber ingestion causes fecal loss of lipids and nitrogen (Southgate, 1973) and leads to a slight energy loss. Suggestions for Recommended Daily Allowance of Fiber Spiller (1977) assumed that an intestinal transit time less than three days would not cause colonic intraluminal stress. Therefore, he suggested a daily allowance of any fiber component of combination yielding a transit time of no longer than three days. Based on correlation between fecal weight and transit time, this allowance can be con- verted to the amount of fiber which produces at least 150 gm of fecal weight per day. This suggestion must be adjusted for individual body weight, sex, age, and type of fiber lngested. Analyses of Dietary Fiber Recent studies have emphasized the nutritional function 0f the dietary fibers of plant origin. This has initiated a series of modifications in the methodology of fiber content determinations. 27 There are five methods that have been developed and used to determine fiber content.. All five methods are based on the extraction of a uniformly air-dried sample to remove excess lipid. The fat free or low fat (less than 2 per cent by weight) sample is then extracted successively with various reagents to remove all digestible constituents. These methods use different reagents to obtain varying degrees of accuracy in fiber content determinations. Crude Fiber Analysis (CFA), the oldest method and an Official Method of Analysis of the Association of Official Analytical Chemists (AOAC), determines primarily the residue left after a sequential hot digestion with 1.25% sulfuric acid and 1.25% sodium hydroxide solutions (AOAC, 1975). The Crude Fiber (CF) method determines approximately 50 to 90% of the celluloses, 20% of the hemicelluloses, and 10 to 40% of the lignins, based on the total weight of a sample (Schaller, 1977). Therefore Crude Fiber Analysis under- estimates the total dietary fiber content value. Acid Detergent Fiber Analysis (ADFA) was developed by Van Soest (1963) and has been accepted as an Official Method for feed by the AOAC. He reasoned that the addition of a detergent, cetyltrimethylammonium bromide to the acid extrac- tion, could minimize the nitrogenous materials which were present in the residue of the crude fiber. Therefore, the Acid Detergent method gives a more accurate measure of the cellulose and lignin components than that of the Crude Fiber method. 28 Buffered Acid Detergent Fiber Analysis (BADFA) was developed by Baker (1977). It is a modified Acid Detergent method using a hydrochloric acid-potassium chloride buffer solution as a solvent for the detergent. Baker claimed that the HCl-KCl buffer solution is less corrosive than sulfuric acid and its pH is within that of the human stomach diges- tive medium, so it can be used to simulate the action of human digestive processes. He analyzed the fiber in cereal samples by the CFA, ADFA, and BADFA methods. The result was that the BADFA had the highest recovery of cellulose and lignins; in addition most starches and proteins were removed. Neutral Detergent Fiber Analysis (NDFA) was developed by Van Soest (1963) using a neutral detergent, sodium lauryl sulfare, to measure the total cell-wall constituents in vegetable food stuffs.. This method simulates the action of the human gastrointestinal digestive system. The final residue includes all the cellulose, water insoluble hemi- cellulose, lignins, traces of pectins, gums, mucilages, cutins, and starches. However, the NDFA method is difficult to filter and to remove starch and protein, especially in samples of high starch content. NDFA underestimates the total dietary fiber since the hot water soluble carbohys drates, such as pectins, gums, mucilages, and pentosans (water soluble hemicellulose), are lost in the filtrate. In the Enzymatic Neutral Detergent Fiber Analysis (ENDFA). Van Soest and McQueen (1973) suggested that the addition of alpha-amylase and proteolytlc enzymes, prior to 29 the neutral detergent extraction, aids in obtaining a more complete digestion of starch and protein in the sample, so that one can overcome the difficulties of filtering and foaming during extraction. A suitable lipid extraction, prior to the enzymatic hydrolysis, will also largely resolve these problems. ENDFA is more accurate for samples with high starch and protein content, but it still underestimates the total dietary fiber content. Sources of Dietary Fiber Fiber values obtained from NDF method approximate those of dietary fiber, but very few samples have been analyzed by this method. Spiller and Fassett-Cornelius (1976) compared NDF data, true fiber, and crude fiber of limited number of fruits, vegetables, grains (Table 6) and cereal products (Table 7) (Spiller and Amen, 1975). Several other Crude Fiber and Neutral Detergent Fiber Analyses of bakery materials from natural grains and cereal brans are shown in Table 8 and 9 (French, 1977) and Table 10 (Shafer and Zabik, 1978). Southgate (1976) compared the total dietary fiber and Specific composition of the dietary fiber component of selected vegetables (Table 11) and wheat products (Table 12). His data indicates that the total dietary fiber in both Vegetables and fruits is relatively low on a fresh basis, although it represents a substantial proportion of the solids in some of these foods. The lignin values for most 30 Table 6. Approximate dietary fiber content pf some common food stuffs (gm/100 gm dry matter) Total True Crude Approximate Food pectin fiber fiber error NDF (TP) (TF) (CF) (CF/TF) % % % % % Apple 12 17 29 9 69 Cabbage* l4 5 l9 8 59 Carrots 9 9 18 6 79 Lettuce l7 4 21 12 43 Whole corn l3 negligible 12 3 77 Whole oats 31 negligible 31 13 58 Wheat bran 45 negligible 45 ll 76 Rice bran 24 negligible 24 13 46 1 Spiller and Fassett-Cornelius (1976) Table 7. Comparison of neutral deterge t fiber and crude fiber value in selected foods Neutral Crude Foodstuff Dry Matter Detergent Fiber (%) (%) (%) White pan bread, enriched 64.2 3.3 1.7 Whole wheat bran 64.4 14.9 5.1 Kelloggs All Bran 97.3 34.0 9.2 Kelloggs Special K 96.2 7.4 1.1 Kelloggs Corn Flakes 96.3 7.9 1.4 Nabisco Shredded Wheat 95.5 22.4 3.6 Ralston Purina Wheat Chex 96.4 17.6 3.5 General Mills Cheerios 94.0 8.8 2.7 General Mills Wheaties 95.0 13.8 3.0 * 1Spi11er and Amen (1975) 31 Table 8. Comparative fiber data from crude fiber and neu- tral detergent fiber analyses Foodstuff Neutral Detergent Fiber Crude fiber (%) (s) Wheat bran 34.8 7.4 Linseed meal 20.2 7.2 Soy hull 63.1 36.0 Rice bran 21.3 7.0 Soy concentrate flour 7.2 3.1 Corn germ meal 43.9 11.2 Corn bran 61.7 14.6 1French, 1977 32 Table 9. Proximate analyses of various agricultural products Crude 221:3- Foodstuff Protein Fat Ash Fiber hydrates (%) (3) (%) (%) (g) Wheat bran 17.2 4.3 6.0 9.6 62.9 Wheat.shorts 19.5 5.4 5.5 8.4 61.6 Wheat middlings 17.8 4.0 6.5 10.2 61.5 Wheat germ 27.9 8.3 5.6 4.3 53.9 Wheat germ, 30.4 0.8 5.9 4.5 58.4 defatted Brar1 from bulgur 16.3 5.8 3.6 10.9 63.4 operations Corn hull 6.9 1.7 1.3 14.4 75. COYTI germ 16.4 21.4 11.9 8.3 42.0 (dry milling) Corn germ expeller 19.0 6.2 7 3 6.0 61.5 cake Corn gluten feed 20.0 2.9 3.9 7.9 64.9 Corn germ 13.0 37.4 1.1 7.8 40.7 (wet milling) Corn germ (wet 25.2 3.4 2.2 12.0 57.2 mill ing defatted) Barley! sprouts 28.8 1.7 5.6 14.8 49.1 Barley! screenings 11.5 2.8 16.7 13.1 55.9 Barley! dust 19.3 2.3 13.6 17.7 49.1 Milo htflls 8.7 2.9 6.8 17.9 63.7 Soybean hulls 10.4 1.6 4.4 41.1 42.5 Linseed meals 39.0 4.6 8.8 7.5 40.1 __~ 1French, 1977 33 Table 10. Proximate analyses of cereal brans1 Ether Neutral Type Extrac- Deter- Moisture Protein table Ash gent (%) (%) lipid (%) (%) (%) Corn 4.0 6.0 1.1 0.3 63.96 Soy 5.5 13.3 3.5 4.6 56.68 Oat 6.9 28.2 5.8 6.0 19.12 Commercial wheat 7.8 14.5 5.0 5.6 39.63 Soft white wheat: Ionia 6.7 14.2 4.5 5.6 38.22 Yorkstar 6.6 13.2 4.7 .5 37.41 Soft red wheat: Oasis 7.4 15.5 4.9 5.4 38.46 Arthur 5.8 15.6 5.4 5.8 40.45 Hard red wheat: Comanchee 8.8 13.6 3.5 5.3 44.88 Shawnee 8.6 13.9 3.9 5.9 36.79 1snafer and Zabik, 1978 mum? .eeeuepsemp 34 3e; me mm mm mm as we _.m_ NP.N seeeezeeem :me + gmmpe mm me mm m_ mF mo mm.m mm.F 3mg Eapa »_co smmpm mm we om m_ mm em n.¢— ee.~ some mcecmm RN mp em m_ Fm em mm.m mm.~ apco cmmF$ oe mm om _ mm mm e_.m Ne._ spaa< . Axesv cc me «F _m mm Ne m.PN oe.F oueeoe Axes .cmNosmv om mm we N RN mo c.5e mu.“ mama Aumxoouv me mm cm s» cc om o.wm o~.m mpossmu Aumxoouv mm mm 8_ Le me am 8.Nm mm.~ endgame mauve -msuommzpoa memes mu_u< mmop uwmopap_mu p:m_m3 memes owcoez mmmoucma mmmoxm: cwcmwg sappmu -coz Ago co named co noon Axv cowpumed owmoF=FPmu Axv swarm xsmumwo Am oo_\mv emcee -coz exp mo cowp_moasoo meg mo :owpwmoaeou zsmumwo Peach mepnepmmm> new mpwaee msom cw sma_e asmumwu eo coww_moQEoo _muoh .- m_nm» 35 mwmma gmuume age m com mnmp .mummgpsom F NF mm m_ m m_ cm oo.we :msm m? we mm m cm mm oo.P_ Laopm meEmFogz _F me ee o_ mp Ne oe.m Aamm-omv snoFu czocm m P_ om _ ms om me.m Asmsv Leora news: mmuws tmsuommzpoa mnwo< owmopappmu Nam oo_\mv owcoL: mmmopcma mmmoxm: cwcmwg mmopaypmu scoz cone; mmc_gm;uommx_oa owmoP=Fpmo Afiv Leave acmpmwo Asmuwwo we» mo cowuwmoaeou P p H 1:0: mgu mo covgwmoaeou Pmpoauoga paws: meow cm cowuwmoaeou my? new smnwm Asmumwc Fmpop one .NF mpnwh 36 vegetables are very low. Fruits containing lignified seeds and cells such as strawberry and pear are high in lignin value. The noncellulosic polysaccharides in vegetables and fruits are usually rich in uronic acids and pentoses. Whole wheat and rye have relatively higher percentages of fiber than their representative refined flours. Total dietary fiber increases as the extraction rate of the flour is increased. Bran which contains very small amounts of endo- sperm represents the maximum fiber value. The lignin value of the flour also increases from low to high as the percen- tage extracted increases (Table 8). Various fiber sources can be identified from current tables of food composition which list crude fiber data. This crude fiber data tabulated in Table 13 and 14 can serve as a guide to foods high in dietary fiber until an accurate quantification of dietary fiber content in foods has been clarified by the scientists. Several types of commercially purified fibers are now available (Lang and Briggs, 1976). Avicel-Rc is a white hygroscopic powder containing 92% Microcrystalline cellulose and 8% sodium carboxymethyl- cellulose. It has been used in formulating varieties of low-caloric products, such as honey-flavored doughnuts, peanut butter dried mix, bran muffins, layer cakes, fibrous breakfast food, chocolate pudding, sauce, salad dressings and candy. Solka-Floc is a purified cellulose which con- tains 99.5% fiber (89% cellulose, 10% hemicellulose, 0.3% 37 Table 13. Crude fiber and calorie content of cereals, roots, tubes and seeds Crude Fiber Calories (%) (Kca1/100 gm) Barley, whole dehulled 2.0 353 Barleyu pearled 0.8 35] Whole maize 2-0 363 Maize meal, 96% extraction 1.5 352 Maize meal, 60% extraction 0.7 354 Corn ‘flour 0-2 352 Whole nfillet 3.0 336 Millet meals 2.4 332 Oat meals 0.9 350 Brown rice 2-0 360 White» skinned rice 0.7 354 Polished rice 0.25 352 Rye meal, 80 to 90% extraction 1.5 350 Whole sorghum 2.0 355 Whole wheat meal - 100% extraction 1.6 - 2.1 344 Whole wheat meal - 85% extraction 0.4 - 0.9 345 Whole wheat meal - 70% extraction 0.2 350 Wheat bran 10.5 - 13.5 300 Cassava, fresh 1.0 153 Cassava flour 1.5 342 Irish potatoes 0.4 75 Sweet potatoes 1.0 114 Sago f’lour trace 352 Planta'Hi 0.3 128 Banana. 0.3 128 Fresh (yam 0.5 104 Sugarczane stem 2-1 50 Chick pea 2.8 368 Fenugreek 7.2 335 Dry ground nuts 3.0 579 Horse gram 5.3 338 Kidney bean 4.0 339 Lathyrus pea 15-0 293 Lentil 4.0 339 Lima bean 5.0 326 Mung bean 4-5 329 Fed. mature 4-5 337 Pea, immature 1.0 70 Pigeon pea 7.0 323 Soybean mature 4-5 382 Soybean, immature 1-9 139 Oil seeds, nuts, most varieties 2.5 400-700 Sesame seeds 12}3 155 ‘ 1 Burkitt and Trowell, 1975 38 Table 14. Crude fiber and calorie content of vegetables, fruits and seaweeds Crude Fiber Calories Foodstuffs (%) (Kcal/100 gm) Most vegetablesz 0.5-1.5 30-50 Most fruits? 0.5-1.5 50-150 Dried dates? 2.4 303 Dried figs2 11.0 269 Orange peel, raw 3.7 92 Orange peel, dry 13.7 307 Lime rind 3.2 71 Kumquat fruit 1.5 48 Guava 5.6 69 Jackfruit, immature 2.8 53 Jujube (Chinese dates), dried 2.9 281 Jamaica-cherry 2.0 87 Grape 3.5 69 Indian gooseberry 2.4 58 Fresh ‘fig 1.5 59 Dried 'fig 7.2 278 Crabapple 1.7 89 Cranberry 1.4 46 Calabao 1.5 35 Apricot, dried 4.1 245 Sweet {Jotatoes 1.6 42 Sesban ia raw leaf 3.9 45 Agar, dried 2.7 83.5 Laver (porphya) 4.7 44.5 Seagir1a iaponica, dried 4.8 43.9 Undaria.p1nnatified, dried 3.6 51.4 Ulva_l§ctuca, dried 4.6 46.7 1 2 Leung et al., 1972 Burkitt and Trowell, 1975 39 lignin, and 0.1% ash). Several food grades of Solka-Floc have been produced and have been used successfully in meat products, pasta products and snack foods (McCormick, 1976). Nutrifibers are the product made from soybean hull, conta ining 40% fiber. Protex is a high protein, defatted rice laran and contains 6 - 8% crude fiber. By-products of both soybean and wheat millings have been suggested in the formation of expanded snack foods with excellent physical characteristics (Breen et al., 1977). Use of Dietary Fiber in Food Systems Broth alpha-celluloses and cereal brans have been recommeended as good sources of dietary fiber for their func- tional bulking properties in food and nutrition. Micro- crysta'lline cellulose has been used as a partial substitute for wheaat flours in the production of muffins, cookies (Lee e't al., 1968), cakes and biscuits (Brys and Zabik, 1976) and mashed potatoes (Lee et al., 1968) for use in low caloriee diets. Zabik et a1. (1977) reported on substitu- tions \uith 8 kinds of celluloses (Solka-Floc Bw-200, Avicel PH-lOl, Prototype sample #170-2, Prototype sample #174-2, Prototype #170-2, plus CMC, Prototype sample #174-2 plus CMC, Prototype sample #174-2 (85%) coated with 15% NF grade citric pectin, and 70% Prototype sample #174-2 coated with 30% NF grade citric pectin for 30% of the cake flour in high ratio layer cakes. The results indicated that all cakes were of good quality with few significant differences 4O occurring among the objective and sensory data. However, cakes containing pectin-coated cellulose had compact, gummy, soggy and dough-like textures and were slightly gray in interior color. Rajchel et a1. (1975) reported that up to 16% wheat bran .and 12% middlings could be successfully used in place of flour and incorporated into chocolate, banana, nut and spice cxmes. Brockmole and Zabik (1976) also indicated that replacement of flour with 16% wheat bran and 12% middlings in whi te layer cakes was acceptable. They found that the partic'le size of the bran used in these cakes could affect the quaality characteristics. Springsteen et a1. (1977) indica ted that the fineness of grind was important for suc- cessfu'l incorporation of bran into cakes and f0und that substi tution of 30% of the cake flour with a finely ground bran p>roduced acceptable cakes. The behavior of wheat brans (and other cereal brans in white layer cakes was com- pared lay substituting three types of wheat brans (hard red, 11ard white, and soft red), corn bran, soy hulls and oat bran for 30% of the cake flour (Shafer ana Zabik, 1978). Successful results were obtained in the layer cake systems at the level of 30% substitution of wheat and corn brans. Though cake batters containing non-wheat brans had higher batter viscosities, the resulting cakes were less tender than the cakes made with wheat bran. In addition, cakes with oat and soy bran had less pleasant flavor and were not acceptable to taste panelists. These researchers indicated 41 that cakes could be successful carriers of dietary fiber in food systems. Since the cellulose and hemicellulose levels in millet are fligh, millet is another source of dietary fiber. It is mostly consumed locally in Northern China, India, Africa and Southern Russia (Casey and Lorenz, 1977). Leavened breads cannot be made from 100% millet, since it does not contaidi gluten-forming proteins (Badi et al., 1976). The use of nfillet flours leads to rather compact pan breads with dense texture (De Ruiter, 1972). Therefore millets must bee baked into flat breads, as is done in Eastern Europe and Aficica. In the Western world millet flour has been substi tuted in bread, cookie, and biscuit formulations for part 0'f the wheat flour. This results in a different and distin<:t flavor in these baked products. However millet flour (alone does not produce acceptable cookies. Addition of soytoean lecithin for millet flours at the 0.6% level greatl;y improved top grain and cookie spread. The quality of these cookies, however, was not that of cookies made solely! with wheat flour. Biscuits formulated with millet flour and 10% wheat flour were given acceptable consumer responses in Nigeria (Casey and Lorenz, l977). Vratanina (1978) reported that highly acceptable cookies could be formulated by incorporating red and white wheat brans up to the 30% level in sugar snap cookies, and UP to 50% in oatmeal cookies. A 30% substitution of flour with wheat bran in sugar snap cookies did not significantly 42 affect the top grain but did reduce the spread factor. Bran darkened the color and yielded more tender, less crisp cookies. Khan et a1. (1976) incorporated coconut residue in sugar cookies at 5, 10, 15 and 20% levels. An excessive amount of water was required to mix an optimum sugar cookie dough when more than 10% coconut residue was incorporated. Cookies made with 20% coconut lowered the spread factor, but the aroma, taste and texture were acceptable. The crude fiber content increased from 0.14% in the control cookies to 2.02% for the 20% substituted cookies. Of all cereal foods, bread is the most popular (Scade, 1951). Many varieties of bread are made from whole grain meals and whole grain brans. Bakery scientists have repor- ted that breads can be a feasible carrier of dietary fiber. Whole wheat flour and from 5 to 16% wheat bran can be satisfactorily substituted for white flour in bread and muffins (Pyler, 1973). Defatted corn-germ flour which con- tains 15.9% dietary fiber has been partially substituted for flour in bread. Acceptable corn-germ bread having a specific volume of more than 6.00 cc/gm could be prepared from wheat flour replaced with 12% of corn-germ flour (Tsen, 1975). Tsen reported that by using a stronger wheat flour (13.6% protein and 0.53% ash), an acceptable bread could be produced with 18% corn-germ flour. Coconut residue is a fiber-rich by-product (16% crude fiber) obtained from the aqueous processing of fresh coco- nut. Replacement up to 10% of wheat flour with coconut 43 residue in white pan bread yielded an acceptable product (Khan et al., 1976). This coconut bread contained approxi- mately 7.5% crude fiber. Lorenz (1976) reported that replacing up to 15% of wheat flour with brans from triticale and rye increased farinograph absorption and decreased mixing time and mixing tolerances. Amylograph studies of blends of wheat flour and triticale bran showed that these were less viscous probably because of a high alpha-amylase activity in the bran sample. Fine bran caused greater changes in viscosity than coarse bran samples. Good quality breads were baked with the fine bran samples, up to replacement levels of 15%. There was no decrease in bread volume. Proof time of breads with 10 and 15% bran were shorter than those of control breads. Loaves baked with 10 and 15% fine bran samples were softer than the control loaves after 6 days of storage. The importance of bran particle size in deter- mining bread baking characteristics was apparent. Pomeranz et a1. (1976) used wheat bran, all malt spent grains, and malt-grits spent grains to replace wheat flour at levels of 0, 3, 5, 7, 10 and 15% to produce high fiber breads. They found that all three fibrous materials in- creased water absorption. The increase was largest for the malt-grits replacement and smallest for wheat bran. The loaf volume decreased and the crumb grains were impaired with increasing fiber replacement levels. The decreased bread loaf volume was due to dilution of gluten protein 44 from the substitution of various fibrous materials. As a result, the bread made from white wheat bran-enriched was superior in loaf volume, crumb grain and crumb color to the bread in which the brewer's spent grains and all malt- corn grits were added. Prentice and D'Appolonia (1977) made high fiber bread containing brewer's spent grain (830) at 5, 10, and 15% levels of substitution. Consumer panels accepted favorably the bread made with the BSG for flour at 5 and 10% levels of replacement.. Crude fiber and acid-detergent fiber were approximately double in flour with 10% B80 substitution. Volpe and Lehmann (1977) used 10% alpha-cellulose blend (88.6% alpha-cellulose and 11.4% Vital wheat gluten) to replace wheat flour in 70/30 sponge-dough method. As a result, bread which contained cellulose had a lower loaf volume than either the unbromated or bromated control breads. The over-all quality of the bread containing cellulose was lower than the control bread for most of the characteris- tics evaluated. The addition of fiber to the bread had a slight darkening effect on the crumb. The fiber bread required more force for compression at the end of seven days, but the amount was not significantly higher than the control bread. The use of alpha-cellulose in white pan bread was found to be feasible. Over-all quality of the bread was affected by the addition of fiber, but the products were acceptable. 45 Formation of Snack Chip Structure The basic dough processing technique of extruded starch- based snacks is similar to the dough formation of any baked product. Cereal flours can be used to control both the rheology of the fabricated system and a variety of textural functions such as mouth feel and consistency of foods. Coarseness or smoothness in the fabricated structure can be modified by granulation of the cereal flour. Products formulated with cereal starches may range in texture from light, fragile, highly puffed open cell structures to a dense, crisp product with very close cell structures. These snacks are normally processed by extrusion or a similar process, and followed by baking or deep-fat frying (Feld- berg, 1969). In general, snack chips are prepared by mixing dry ingredients and liquid to form a dough with a moisture con- tent from 25 to 45%. The dough is kneaded until it becomes pliable and forms a thin sheet. Pieces are cut from the thin dough sheet using a rotary cutter or dicer of the extruder and are deep-fat fried to a final moisture content of 0.2 to 5.0% (Campbell and Liedman, 1976). Wheat flour is the best source for the development of a dough with good extensibility and elasticity. The protein and starch components of wheat flour contribute to the main structure of the dough and to the finished products. Addi- tion of tuber materials such as cassava and yam increases water absorption and modifies dough structure because of the 46 dilution effect on gluten (Ciacco and D'Appolonia, 1977). The dilution of wheat flour with casava has been found detri- mental to the wheat protein quality. The addition or replace- ment of the part of the flour with non-gluten materials such as fiber, bran, and commercial cellulose shortened the gluten strength and impaired the quality characteristics of the baked products. The extensibility of dough decreased as starch or non-gluten materials increased (Heaps and Coppock, 1968). In contrast to baked products, snack chips possess a dense, crisp and close cell structure. To obtain satis- factory handling characteristics, snack chip dough should have enough cohesiveness and extensibility to stick together as a sheet, but not be so much elasticity that it resists extension. Therefore, some dilution of wheat gluten to reduce the elasticity is beneficial. Mixing of the snack chip ingredients yields an appar- ently homogenous mass (Bushuk, 1966). At the beginning of the mixing process, a mass or wet lump with little cohesive- ness is formed. Gradually the cohesiveness increases, and the dough develops elastic properties and begins to pull away from the mixing bowl. Continued mixing makes the dough smoother and its appearance drier (dough development). The function of mixing is at least twofold: even distribution of the ingredients, and development of gluten structure. These changes are accompanied by hydration of the ingredients, which is facilitated by blending. Hydration of protein is a condition for gluten development. This development is 47 based on the formation of a network of protein molecules with occasional cross-links. The rheological properties of dough are primarily determined by its continuous phase, the swollen protein. This continuous phase contains the gluten proteins which form thin extensible and compressible films. The snack chip dough must be sufficiently rigid to form a thin sheet that can withstand rolling yet still remain a continuous mass, so that large surface blisters will not be formed during fry- ing (Robbins, 1976). The viscous and elastic properties of dough are pri- marily due to the properties of its continuous or gluten phase. The rheological properties of such a network greatly depend on the number and strength of the cross-links between the protein molecules (Heaps et al., 1967). The insolubility of the gluten proteins is due to their intermolecular hydrogen bonds (Redman and Ewart, 1967). The viscous flow is a result of thio-disulfide interchange reaction in the protein network. Thio-disulfide interchange during mixing causes the formation of a protein network in dough, in which protein molecules originating from different flour particles are cross-linked one with another. In this way they form a continuous and coherent phase. The observa- tion that the interchange reaction is most rapid in wheat flour dough, slower in doughs from rye, and still slower in dough from other cereals may offer an explanation for the differences in gas retention between these doughs (Redman 48 and Ewart, 1967). In general, there is a correlation between the resis- tance to mixing and between dough development times as determined with various recording mixers. In the same way there is a correlation between the resistance to deformation and between the extensibilities of the curve provided by various load-extension meter. Dilution of gluten will result in low resistance to mixing and a short time dough development. When a dough is formed, water is taken up by the flour constituents in proportion to their capacity. Bushuk (1966) indicated that about 46% of water in dough is associated with starch, 31% with gluten, and 23% with pentosans. Wheat flour contains approximately 2% pentosans; they form a soft- gel upon hydration and contribute significantly to dough consistency. Since pentosan molecules cannot penetrate the starch granules, they form an intimate association with the gluten in which are embedded the starch granules in a dough system. Bechtel et a1. (1971) indicated that pentosans from wheat flour could readily disperse in water, forming highly viscous solutions. D'Appolonia and Kim (1976) repor- ted that water insoluble pentosans interact with gluten to increase the resistance of dough to extension thus decrea- sing its extensibility. It has been postulated that pento- sans and glycoproteins are present as transitional compounds, which play a part in the physical association and chemical bonding between carbohydrates and proteins. Patil et a1. 49 (1975) found that the hydrogen bonding capacity of water- soluble pentosan molecules intensified the association between carbohydrate and protein constituents in the dough formation. It is not known if water-insoluble pentosans play a similar role. The water-insoluble fraction of the wheat endosperm cell walls are arabinoxylans, which are held within the cell wall structure by ester linkages between adjacent arabinoxylans and other cell wall polysac- charides. During the deep-fat frying process, starch components of the wheat flour upon gelatinization absorb a great amount of the available moisture from the hydrated gluten and pen- tosans. They thus become thermoplastic and develop a dis- tinct structure (Smith, 1976). According to Sandstedt (1961) starch functions to dilute the gluten, to provide a surface for union of gluten, and to become flexible during gelatinization and provide a structure permeable to gas so that baked breads do not collapse on cooling. In snack chips, gelatinized starch also lends a brittle texture to the finished product. Shortening is also an important ingredient in snack dough formation. It functions as a lubricant and shor- tening agent. The selection of the type of shortening is important for textural properties. Other ingredients, selected for functional charac- teristics include leavening agents such as sodium-aluminum sulfate (SAS) baking powder to give a crumb texture to the 50 chips. SAS baking powder produces carbon dioxide to modify the quality of the chip and results in an optimum amount of friability, density, and crispness. As materials are substituted for wheat flour, water must be added proportionately to the level of the water- holding capacity of the material substituted. The total moisture content of the dough may vary somewhat depending on the particular starchy food material being used, but it will range from 25 to 45% by weight (Robbins, 1976). The desirable moisture level is about 40%. There are some differences in the basic expanded product, principally in texture and eating qualities (Nadi- son, 1969). The type of extruder and process used to pro- duce the basic product can alter snack chip characteristics. Basic formulations may vary somewhat, depending upon whether the product is produced by hot or cold extrusion, and whether the resulting extruded product is baked or fried. Corn, rice, potatoes, modified food starches, wheat flour, soy protein, and even high fiber-high protein mater- ials have been used in producing expanded snack products. All of these impart unique flavors and properties to the finished product. The addition of seasonings makes the product unique and acceptable to the snack consumer. The method of intro- ducing seasoning into the spicy products is done by dusting or spraying the seasoning over the finished snack after frying or baking (Nadison, 1969). Dusting or spraying is 51 advantageous because it allows for the application of a large variety of seasonings. Also the seasoning are not exposed to extremely high temperatures, which minimizes the escape of volatile aroma components. Seasoning and flavor should be applied at low levels, with just enough used to impart the desired flavor. This allows the product to be seasoned and prevents an undesirable build-up of flavor. EXPERIMENTAL PROCEDURE This research was initiated to determine whether the dietary fiber constituents of dehydrated carrot powder and solka floc BW-200 could be satisfactorily substituted for bread flour in a chip type snack food formulation, and to determine the dietary fiber content of various types of com- mercial baked products and snack foods. Additional tests were carried out to determine the dietary fiber contents of traditional home-made whole grain and fruit-type breads. Food Material and Chemical Procurement Common lots of salts, sugars, shortening, baking pow- ders, bread flours, white sesame seeds, Parmesan cheese, garlic salt, and corn oil were purchased from the Michigan State University Food Stores. Sugar free egg powder was donated by Seymour Foods Company, Kansas. Fresh carrots were donated by Dr. Jerry N. Cash, Assistant Professor in the Food Science and Human Nutrition Department at Michigan State University. Ground cellulose sold under the trade name of solka-floc BW—200 was obtained from Berlin Brown Company. Rye flour, yellow corn meal, whole wheat flour, all purpose flour, wheat germ, dry apricots, dry figs, raisins, apples, bananas, breakfast cereals, bar cookies, 52 53 oat cookies, walnuts, dry active yeast, caraway seeds, whole wheat bread, pumpernickle, schwazbrot, and stollen were purchased from Meijers Thrifty Acres. Ardex-700F defatted soy flour was donated by Archer Daniels Midland Company, Illinois. Wheat brans were donated by the soft Wheat Quality Laboratory of the Ohio Agricultural Research Development Center, Wooster, Ohio. Flat crisp whole grain breads were purchased from the Grande Gourmet retail store. Sodium lauryl sulfate, disodium hydrogen phosphate, and 2-ethoxyethanol were purchased from Fischer Scientific Company. Disodium ethylene-diaminetetraacetate (EDTA) and sodium borate decahydrate were purchased from Michigan State University General Stores. Alpha-amylase (type VI-A) obtained from hog pancrease was purchased from Sigma Chemicals. Carrot Chip Formulation A Chinese sweet wheat chip formulation (Table 15) was modified to prepare eight spicy carrot chips and a con- trolled plain wheat chip. Five replications of each vari- able were evaluated objectively and subjectively. The flour component of the control wheat chip was substituted with 10%, 20%, 30%, 40% of the dehydrated carrot powder, respectively. In addition, 4% and 8% ground cellulose were used in place of part of the dehydrated Carrot powder at both the 20% and 30% levels (Table 16). Preliminary experi- ment were conducted to determine the optimum water and 54 Table 15. Formulation for Chinese Sweet Wheat Chips1 Ingredients % weight/100% flour Bread flour 50.0 All purpose flour 50.0 >100'0 Fresh eggs 20.0 Soy-bean curd (90% moisture) 40.0 Sesame seeds 7.0 Sugar 30.0 Shortening 3.0 Salt 1.0 Baking powder 0.5 Anon 55 Pocucou cw new: LaoFm mo mswcm oo_ mgu eo mmmucmucma mm ummmmcaxw cowwmpzsgoem Pogucoup o.mw o.mw o.ow o.om o.om o.mw o.ow o.om 0.0m empmz ~.P n._ m.~ m.~ N.F n._ m.P o.F o.p gmuzoa mcwxmn mme mmpomwgm> mega posgmo zueam usmwm use menu paws; pogpcou we cowpmpzecom .op epoch 56 baking powder level for each variable. Preparation of Dehydrated Carrot Powder Thirty kilograms of fresh carrots were washed, peeled, trimmed and shaved into strips. The strips were collected in a container which contained 1% salt water. The carrot strips were drained in a plastic basket, before being dipped in a 0.3% sodium bisulfite solution for 3 minutes. Sulfite treated carrot strips were drained and dried at room tem- perature for 30 minutes. The carrot strips were then dehy- drated in an air-blast oven, Proctor & Schwartz, model K12395, at 205°F (96°C) for the first 30 minutes, after which the oven temperature was reduced to 175°F (66°C) and drying continued for two additional hours. The oven tem- terature finally was reduced to 150°F (64.4OC), and the carrot strips dried for another two hours. The moisture content of the dehydrated carrot strips was 4.5%. The dehydrated carrots were ground into a fine powder using a Udy Cyclone Sample Mill, model MS. Four and a half pounds of carrot powder were obtained and packed in several half- pound polyethylene bags, then wrapped with tin foil and stored in a dark cabinet at room temperature (21°C) in order to prevent carotenoid and xanthophyll degradation by sun light and ultraviolet light. Carrot Chip Preparation All the preweighed dry ingredients except egg powder and Parmesan cheese were mixed and sifted. Water, egg 57 powder, and Parmesan cheese were placed in the bowl of a Kitchen Aid mixer, model KS-A. These ingredients were beaten with a wire whip attachment at medium speed (142 rpm) for 5 minutes until homogenized. The sifted dry ingre- dients were added to the cheese mixture and mixed with a dough hook at low speed (60 rpm) for 3 minutes. The shor- tening was added and beaten at medium speed for 7 minutes until the dough was just developed. The dough was condi- tioned at room temperature (21°C) in a tightly covered container to prevent moisture loss for 2 hours. Each dough was divided into five equal parts and rolled into approxi- mately 0.08 cm thin sheets with a wooden rolling pin. Four sheets were cut into 4-cm diamond-shaped pieces (Figure 3); the fifth sheet into 4-cm square-shaped pieces (Figure 4). These pieces were deep-fat fried in a General Electric Hotpoint deep fat frier, model HK3 at 365°F (185°C) for 15 seconds and finished drying at 250°F (121°C) in a 12 l-lb. loaf size National Reed Type Test Baking Oven for 10 min- utes. After cooling at room temperature (21°C), these diamond-shaped chips were packed in several polyethylene bags, sealed, and stored at room temperature (21°C) and 60% relative humidity. The diamond-shaped carrot chips were used for sensory evaluations. The square-shaped carrot chips were pressed into flat pieces within 5 seconds after deep-fat frying and before they finished drying. These square-shaped carrot chips were packed and sealed in the 58 \ / Figure 3. Cutting diagram for square-shaped raw carrot chip dough 60 same way as the diamond-shaped ones, except that they were stored in a desiccator at room temperature (21°C). These chips were used for color and Allo-Kramer shear press tests. Objective Measurement Objective measurements were used to determine the quality characteristics of the carrot chips. These included moisture content, color, and crispness (or breaking strength). Moisture. Moisture determination was done on both the raw dough and the finished product by drying 2.000 1 0.0001 gm of samples at 100°C under a vacuum of 27-in of Hg in a Hotpack vacuum oven, model 633 for 8 hours (AOAC, 1975). The dried samples were reweighed after cooling in a desic- cator. The percentage moisture was calculated according to the following formula: % Moisture = Weight of Moisture4Loss (gm) x 100 Weight of Original Sample (gm) Color. The surface color of the carrot chips was measured using a Hunter Color Difference Meter, model 025. After standardizing with a yellow tile (L = 83.0, aL = -3.5, bL = 26.5), the measurements were taken. Two reading were taken on each piece of carrot chip and averaged to give individual averages for L, aL, and bL values. Crispness. Crispness of the carrot chips was deter- mined using the standard shear-compression lO-blade cell of .— 61 the Allo-Kramer Shear Press, model SP12. The Allo-Kramer Shear Press (model E2EZ) is equipped with an electronic recorder. The carrot chips were weighed to the nearest 0.01 gm before being placed in the bottom of the standard shear-compression cell. A 3000 pound proving ring with a range 5 was selected for each measurement except for the 40% variable in which case a range of 10 was used. The cell assembly was cleaned with a brush between each measurement. The crispness value expressed as a pound force per gram of sample was determined by a single measurement calculated according to the formula, Reading x Ring x Range (1b force) Sample weight (gm) x 100 x 100 Crispness or Factor x Peak High (lb force) Sample weight (gm) Crispness where the factor of the 3000 pound ring was adjusted perma- nently for this machine to be 3.0 for range 10 and 1.5 for range 5. Subjective Evaluations Two training sessions were held prior to taste panel evaluation to familiarize the panel members with the score card. Twelve panel members were selected out of twenty to be included in the final panel group based on their ability to discriminate and their willingness to serve. A sample score card appears in the Appendix. k _. 62 The sensory evaluations included: (1) Appearance (color, bristles), (2) Flavor (saltiness, greasiness, detectable flavor, and over-all flavor), (3) Texture (fri- ability, crispness, and mouthfeel), and (4) General accep- tability using a descriptive scale. Each characteristic had a continuous scale with descriptive terms placed adjacent to the bar. Each taste panelist marked the bar by the descriptive term best describing the product. These were converted to numerical values by assigning the highest score with the most desirable descriptive term. Home-Made Whole Grain and Fruit Type Breads Ten variables of whole grain breads and fruit-nut breads were prepared by formulations and procedures selected from American Cookbooks. These are shown in Tables 17 to 25. Three replications of each variable were made for determining the Enzymatic Neutral Detergent Fiber content. Thirty loaves of bread in total were baked randomly within two weeks. After each baking, breads were cooled to room temperature, wrapped with polyethylene sheets and stored in the freezer at -20°C for later dietary fiber determination. Home-Made Bread Preparation Material Preparation. Ten types of bread were pre- pared, five were chemically leavened quick bread and five were yeast raised bread. The quick breads included fig-bran bread (Table 17), banana-bran bread (Table 18), bran bread 63 Table 17. Formula for fig-bran bread1 Ingredients % based on flour components Weight (gm) Whole wheat bran 37.0 24.0 All purpose flour 40.0 > 100.0 26.0 Yellow corn meal 23.0 15.0 Dark brown sugar 53.0 34.5 Full fat milk 127.0 82.5 Shortening 60.0 39.0 Dried figs, chopped 77.0 50.0 Baking powder, SAS 3.0 2.0 Fresh eggs 50.0 32.5 Baking soda . 2.0 1.3 1Rombauer, 1942 Oven temperature: 375°F. Product size: 8 x 4” loaf. Baking time: 35 minutes. Table 18. Formula for banana-bran bread1 Ingredients % based on flour components Weight (gm) Whole wheat bran 9.0 8.7 Whole wheat flour 32.0 > 100.0 30.5 All purpose flour 59.0 57.4 Dark brown sugar 45.0 39.0 Shortening 23.0 20.0 Walnut, chopped 18.0 15.7 Dried apricot, chopped 31.0 27.0 Baking powder 1.5 1.3 Baking soda 0.8 0.7 Salt 1.0 0.9 Fresh eggs 27.0 23.5 Vanilla 1.0 0.9 1Rombauer, 1942 Oven temperature: 375°F. Product size: 8 x 4" loaf. Baking time: 35 minutes. 64 Table 19. Formula for bran bread with molasses1 Ingredients % based on flour components Weight (gm) Whole wheat bran 13.0 > 100 0 11.0 Whole wheat flouE 87.0 ' 75.0 Dark brown sugar 42.0 36.0 Full fat milk, sour3 139.0 119.0 Raisins 47.0 40.4 Baking powder, SAS 2.0 1.7 Baking soda 1.0 0.9 Salt 2.0 1.7 Fresh egg 16.0 13.8 1Rombauer, 1942 2 to one and a half parts of dark brown sugar. If molasses was used, one part of molasses would be equal 3One cup of full fat milk and one teaspoon of vinegar were mixed to make sour milk. Oven temperature: 375°F. Product size: 8 x 4" loaf. Baking time: 40 minutes. Table 20. Formula for zucchini1 (or carrotz) bread Ingredients % based on flour components Weight (gm) A11 purpose flour 100.0 63.7 Fresh eggs 43.0 27.0 Dark brown sugar 122.0 76.9 Grated zucchini (or carrot) 107.0 67.4 Shortening 69.0 43.5 Chopped walnuts 36.0 22.7 Baking powder, SAS 2.3 1.4 Salt 1.7 1.1 Vanilla (for zucchini bread) 3.0 1.9 Cinnamon (for carrot bread) 5.0 3.2 Baking soda 1.2 0.8 1Behan, 1976 2kent, 1976 Oven temperature: 350°F. Product size: 8 x 4" loaf. Baking time: 45 minutes. Table 21. Formula for rye bread1 65 Ingredients % based on flour components Weight (gm) Whole wheat flour 40.0 > 100.0 57.0 Rye flour 60.0 70.5 Dark brown sugar 19.0 22.5 Salt 2.0 2.3 Shortening 2.0 2.3 Dry active yeast 3.2 3.5 Luke-warm water (38°C) 85.0 100.0 Caraway seed 1.0 1.2 Grated orange skin 5.0 6.0 Fine chopped apricot 40.0 47.0 1Rombauer, 1942 Oven temperature: 425°F. Baking time: 35 minutes. Product size: 8 x 4" loaf. Table 22. Formula for raisin-nut rolled oat bread1 Ingredients % based on flour components Weight (gm) Whole wheat flour 75.0 59.0 Oat meal 25.0 > ‘00'0 20.0 Full fat milk 143.0 113.0 Molasses 13.9 11.0 Yeast 2.3 1.8 Raisin, chopped 45.6 36.0 Salt 1.9 1.5 Water 71.5 56.5 Nut, chopped 38.0 30.0 1Rombauer, 1942 Oven temperature: 400°F. Baking time: 35 minutes. Product size: 8 x 4" loaf. 66 Table 23. Formula for rolled oat nut bread1 Ingredients % based on flour components Weight (gm) Whole wheat flour 75.0 59.0 Oat meal 25.0 > ‘00 20.0 Full fat milk 143.0 113.0 Molasses 13.9 11.0 Yeast, active dried 2.3 1.8 Water 71.5 56.5 Walnuts, chopped 38.0 30.0 Salt 1.9 1.5 1Rombauer, 1942 Oven temperature: 375°F. Product size: 8 x 4" loaf. Baking time: 45 minutes. Table 24. Formula for apple bread1 Ingredients % based on flour components Weight (gm) Bread flour 100.0 106.0 Shortening 11.0 11.6 Active dry yeast 1.3 1.4 Salt 1.1 1.2 Water 20.5 21.7 Apple, McIntosh2 148.7 157.6 1DeBoth, 1929 2Freshly peeled and cored Oven temperature: 410°F. Product size: 8 x 4" loaf. Baking time: 25 minutes. 67 Table 25. Formula for raisin bread1 Ingredients 1 % based on flour components Weight (gm) Bread flour 100.0 100.0 Sugar 4.0 4.0 Active dry yeast 3.0 3.0 Salt 1.0 1.0 Shortening 4.0 4.0 Water 80.0 80.0 Raisin 80.0 80.0 1Bennion, 1967 Oven temperature: 392°F. Product size: 8 x 4" loaf. Baking time: 25 minutes. with molasses (Table 19), zucchini nut bread (Table 20), and carrot nut bread (Table 20). The yeast raised breads were rye bread (Table 21), raisin-nut rolled oat bread (Table 22), rolled-oat nut bread (Table 23), apple bread (Table 24) and raisin bread (Table 25). The ingredients were prepared as follows: fresh bananas were chopped and mashed, walnuts and dried fruits were chopped into finely uniform particles, and raisins were soaked in warm water (36°C) for 30 minutes, after which they were drained dry and then chopped. All the dry ingredients were preweighed to the nearest 0.1 gm. The materials for each variable were packed in individual plastic bags, and stored in a freezer at —20°C. The individual packages were thawed at room temperature for 30 minutes before mixing the dough. Methods and Procedures. A straight dough method was used to mix the yeast raised breads and a conventional method was applied to quick breads. 68 Straight dough method: A desirable amount of active dry yeast was allowed to rehydrate in luke-warm water (yeastzwater = 1:5) at ca 38°C for 5 to 10 minutes just before mixing the dough. Then the yeast water, sugar, salt, eggs, milk, and any semi-liquid materials such as oat—milk mixture, banana puree, or apple stew, etc. were placed in a bowl of a Kitchen Aid mixer, model K5-A, and beaten at low speed (60 rpm) with a wire ship attachment for 2 minutes. The sifted flour, bran or corn meal was then added to the mixture and mixed with a dough hook at low speed for 3 minutes. The shortening was added and beaten at medium speed (142 rpm) for about 2 minutes, after which the finely chopped dried fruits and nuts were added and beaten at low speed for 2 minutes or until all the ingredients were well mixed. The dough was then placed in a 8 x 4" well greased loaf pan and allowed to ferment at 29°C and relative humi- dity of 75% for 30 minutes. Proofing was continued for another 30.minutes at 38°C and 85% relative humidity. Finally the raised dough was baked at the specific tempera~ ture. Quick bread method: The shortening and sugar were placed in a mixing bowl of a Kitchen Aid mixer and beaten using the paddle attachment at medium speed for 3 minutes until creamy. The fresh eggs were added and mixing was con- tinued at medium speed for another 2 minutes. The grated' zucchini or carrot was then added and mixed for one minute at low speed. All the sifted dry ingredients were added 69 and mixed well with other ingredients. The batter was placed in a 8 x 4" loaf pan and baked at 350° to 375°F for half an hour or until done. All breads were baked in a 12 l-lb loaf size National Reel Type Test Baking Oven. Dietary Fiber Sources in Commercial Baked Products The commercial products selected for enzymatic Neu- tral Detergent Fiber analysis are grouped into 5 categories; (1) Whole grain fresh breads, (2) Breakfast cereals, (3) Cookies and snacks, (4) European whole grain crisp flat breads, and (5) Other food materials. These products are tabulated in Table 26. Determination of Enzymatic Neutral Detergent Fiber This method is based on the method of Van Soest (1973). Food samples were extracted with a hot neutral solution of the detergent sodium lauhvlsulfate. The pH of the extrac- tion medium was 7.0 i 0.1. The detergent solubilizes lipids and protein, EDTA removes minerals. and heat gelatinizes the starches: so that proteins, starches, minerals, and other hot water soluble materials can be separated from the fiber residues through filtration at hot stages. Solution Preparation Neutral Detergent Solution. The following chemicals and amounts were used to prepare the neutral detergent solu- tions: Table 26. source 70 Commercial grain-based products of dietary fiber Source (trade name) Distributor or manufacturer Ingredients contri- buting dietary fiber Whole grain breads: Pumpernickle Schwazbrot Stollen Wheat bread Italian Rye Bread Breakfast cereals: Country Morning Frosted Mini-Wheat All Bran Bran Buds Wheat Chex Raisin Bran Flakes Total Raisin Bran Flakes Cap'n Crunch's Crunch Berries C.W. Post Family Style Cereals Grape-nut Cereal Natural Valley Granola Cinnamon & Raisin Cereal Natural Cereal Cookies and snacks: Fig Bar Old Fashioned Oat Meal Cookies Nature Valley Gra- nola Bar With Coconut May-bud, Purity Cheese Co. May-bud, Purity Cheese Co. West Germany, Grande Gourmet. Awrey Heart Shafer's Bakery Kellogg Kellogg Kellogg Kellogg Ralston Kellogg Purina General Mills Food Club, Topco Ass. Quaker Oats General Foods General Fobds General Mills Nature Valley Alger Candy Co. Keebler General Mills dist. dist. Wheat flour, rye flour. Dark rye flour, soy flour. Wheat flour, raisins, canned lemon and orange peels, apri- cot kernels. Whole wheat flour. Wheat flour, rye meal. Rolled oat, raisins, rice, untoasted coconut, dates, almonds. Whole wheat. Wheat bran. Wheat bran. Whole wheat. Wheat bran, wheat flour, raisins. Whole wheat. Raisin, wheat bran. Corn flour, oat flour. Malted barley, whole wheat. Oats, rice. Rolled oats, raisins, sesame seeds. Whole wheat, raisins, crushed nuts. Figs, coconut, date, almond. Rolled oat, wheat flour. Oat meal, sesame seeds, coconut. Table 26 (cont'd.) Sesame Bran Sticks Sesame Buds Corn Chips Doritos Tortilla Chips Potato Chips Wheat Square Crac- ker Triscuit Honey Sorghum Hearty Wheat Snack Whole Grain Natural Rice European whole grain Crisp Bread With Linseed Siljan Swedish Rye Crispbread Crispbread With Sesame Rogga King's Crisp Bread Ideal Flat Bread Mor Flatbread Other Food Materials: Jiffy Bran Muffin Mix 71 Flavor Tree Flavor Tree Seyfert Planters Spartan Store Kroger Nabisco Inc. Food Club, Topco Inc. Keebler Japan, Health Food store Jans, West Germany Siljan, Sweden Wasa, Sweden Bahlsen, West Germany Vaasa Mill, Finland Norwegian Jakob Haugstad, A.S. Jiffy Sesame seeds, bran, wheat flour. Sesame seeds, wheat flour. Corn. Corn, tomato pulps. Potato. Whole wheat flour, rye flour. Whole wheat. Whole wheat flour. Whole wheat flour. Brown rice. Whole rye, linseeds. Whole rye flour. Whole rye flour, sesame. Whole rye flour. Whole meal rye flour. Whole grain wheat, rye, and barley, caraway seeds. Whole grain rye and wheat flour. Wheat bran, wheat flour, dates. 72 Distilled water, freshly distilled 1.00 liter Sodium lauryl sulfate (USP) 30.00 gm Disodium ethylene diaminetetraacetate 18.61 gm (EDTA), dihydrate crystal, reagent grade Sodium borate decahydrate (NazB407'lO 6.81 gm H 20), reagent grade Disodium hydrogen phosphate (Na 2HPO4) 4.56 gm anhydrous, reagent grade 2-ethoxyethanol (ethylene glycol mono- 10.00 ml ethyl ether), purified grade Sodium lauryl sulfate was dissolved in 500 ml of distilled water in a 1500 ml beaker, after which 2-ethoxymethanol was added to the sodium lauryl sulfate solution, and the mixture continuously mixed with a magnetic stirrer until the solu- tion was clear. The combination of EDTA and Na2B407 10 H20 was completely dissolved with 100 ml distilled water con- tained in a 250 m1 Erlenmeyer flask with the aid of heat. Disodium hydrogen phosphate was also dissolved in distilled water with the aid of slow heat. These two solutions were then added to the sodium lauryl sulfate solution, mixed well and the final volume adjusted to one liter by adding dis- tilled water. The pH of the neutral detergent solution was adjusted to 7.0 1 0.1 with concentrated hydrochloric acid or sodium hydroxide solution when necessary. Since this solution changes gradually with exposure to sunlight, it was stored in an amber bottle. Enzyme solution. The enzyme solution was prepared just prior to use by dissolving 1.0 gm bacterial crude alpha- amylase (Type VI-A) in a 250 m1 volumetric flask with the 73 neutral detergent solution. Extraction Procedure Carrot chips, commercial bakery products, and home-made whole grain, fruit, and vegetable breads were used as the samples for analyses of Enzymatic Neutral Detergent Fiber content. Samples of 0.5 to 1.0 of air-dry, well ground material .(20 to 30 mesh, 1 mm) were measured to the nearest 0.0001 gm and transferred quantitatively to a beaker of refluxing appa- ratus. Forty m1 of neutral detergent solution at room tem- perature was added to the beaker and the mixture was heated to boiling in 5 to 10 minutes. Foaming was monitored, and the heat reduced when necessary. After heating for 15 minutes, the mixture was cooled to 50°C, after which 40 ml of enzyme solution was added, and the starch digestion allowed to continue at room temperature for 30 minutes. The mixture was then refluxed for one hour, and was watched for foaming; the heat was reduced if foaming occurred. A Gooch Crucible was used to filter the neutral detergent extracts under low volume. The reflux beaker was washed with a small amount of boiling water, and this water was trans- ferred to the same crucible. Additional boiling water was . used to wash the extract and this was filtered with as low a vacuum as needed. These steps were repeated until use of the vacuum pulled no more foam from the crucible. Acetone was then added to remove all the lipid that remained with 74 the residue, after which the residue was again filtered with a vacuum as needed. Finally the residue was dried by placing the crucible in a vacuum oven at 100°C for 8 to 16 hours. After weighing, the dry residue was ashed in a muffle oven at 525°C for 8 to 12 hours. The percentage ENDF of a material was calculated as: (Wt. of crucible plus dried ENDF — wt. of crucible plus ash) gm % ENDF = x 100 Original sample weight (gm) Analyses of Data The objective data, sensory evaluation and ENDF data from the carrot chips were analyzed for variance. Duncan's Multiple Range Test (1957) was then used to pinpoint signi- ficant differences among variables revealed by the analysis of variances. RESULTS AND DISCUSSION This study was designed to determine the effects of the replacement of 0 to 40% carrot powder in combination with 4 to 8% commercial cellulose for wheat bread flour on the qual- ity characteristics of carrot chips. Additional Enzymatic Neutral Detergent Fiber Analyses were carried out to deter— mine the dietary fiber content of each carrot chip variable and some selected commercially baked cereal products and tra- ditional home-made whole grain breads in order to assess potential sources of dietary fiber for American consumption. Discussions of the experimental results were based on the numerical data obtained from subjective and objective deter- minations. Tables 27 to 28 present the means and standard deviations as well as a summary of the analyses of variance. Carrot Chips The Chinese wheat chip is primarily flour and can be easily prepared in the laboratory with the use of extrusion equipment commonly used in commercial snack food production. Also several studies had indicated fiber could be substituted for flour in baked products. Carrots were chosen as a high vegetable fiber source while commercial cellulose was used to increase the fiber content. 75 76 Moisture Means and standard deviations of percentage moisture in the raw dough and finished chips are presented in Table 27. Eastwood and Mitchell (1976) reported that 100 gm of raw carrot is able to hold 208 gm of water. Parrott and Thrall (1978) reported that 79 to 232 mg of solka floc can hold 1 Table 27. Means and standard deviations for moisture deter— mination of carrot chips Level of Substitution Moisture Carrot powder Solka-floc Raw dough2 Fried carrot chips BN-ZOO % % % % 0 0 36.67 i 0.02 3.41 i 0.06 10 0 38.70 i 0.01 3.44 i 0.12 20 0 43.33 i 0.02 3.45 i 0.13 30 0 43.76 i 0.02 3.43 i 0.14 40 0 44.79 i 0.02 3.40 i 0.08 12 8 42.17 i 0.02 3.39 i 0.06 16 4 41.92 i 0.01 3.41 i 0.07 22 8 43.64 i 0.02 3.42 i 0.02 26 4 43.68 i 0.03 3.46 i 0.05 1Based on five replications ZSignificant difference at 1% level of probability 1 m1 of water. Therefore, as the level of carrot powder and cellulose was increased in the carrot chip formulation, the amount of water required to produce a consistent dough also had to be increased. The percentage moisture values in the raw dough revealed the expected significant differences (P < 0.01) among variables (Table 28), but no significant differences in moisture content were found in the finished carrot chips. This was probably because the very thin dough 77 see_eeeeoea e6 _e>e_ &_ em eueeeeceee eeeeeeeemem3. m_.c_ mm.o Pm.o w~.o No.o moo.o Nm segue: «3mm.omm 33mm.~m «tpc.o¢ «tmo.cp m_oo.o 33pm.mm m mmFam_gm> mm.mm _—.cp no.5 F¢.N Po.o mm.o we peach meeeu eases 4m an A poctmo 3mm soommcu mmmga cmmgm we mmgmmo mmugzom cOFou mcaumwoz menacm cow: mmoPstmu co\vcm cmuzoa pottmu co mcomngwumnzm sue: umcmamca maenu notcmu mo meowum=Fm>m m>wuumnno to» mucmecm> mo mwmx—m:< .mm mFDm» 78 sheet provided a large surface area that facilitated evapo- ration of water molecules during deep-fat frying. Color Means and standard deviations for the L, aL, bL, and visual color values are presented in Table 29; and a summary of analyses of variance for these data are presented in Table 28 and 30. Duncan's multiple range test revealed that significant differences (p < 0.01) were present in both objective and subjective determinations among variables. As the level of carrot powder increased the L or lightness value decreased, except that the chip substituted with 26% carrot powder and 4% cellulose had slightly higher L value than those substituted with 12 to 40% carrot powder. The aL or redness and bL or yellowness value increased as the level of substitution increased. As the level of cellulose sub— stitution increased the aL or redness value decreased slightly, but L (lightness) and bL (yellowness) did not show any signi- ficant differences among the variables. All the carrot chips had a very pleasant yellow-orange color except that with 40% carrot powder substitute which was scored significantly lower. It may be that with this high level of substitution the finish-drying procedure needs to be modified to reduce sur- face browning. The carotenoid component of carrots was responsible for the predominant carrot chip color. The natural orange yellow color of egg powder and Parmesan cheese also contributed to the color characteristics. 79 gm one at Hcmcmcmwu x—Hcmuemecmwm no: men cmpump 35mm ecu >9 umuawcumcwaam mmmcm>< u ecmp m>wpmwcummu me» Love: mwmmgpcmcma cw emumwp choa mpnwmmoa Pouch .Aemmp .eeeezov seepeeeeOte e6 Fe>ep e...e m mmmczoppm> n An mmmcumm u be mmmccmmgu u 4m- mmmcugmHJ u AN meowpmuepamc m>wm :o ummmmF new.o H mm.m cum. H mp._m npw.o H Fm.m unnm.o H mw.mm a mu n-.o H m~.m um~.o H wF.Fm unpm.o H mm.¢ amm.o H mo.mo m mm ampm. H om.m mmm.o H mo.am uum~.o H m¢.m npw.o H mm.mm e mp ma_.o H N~.m umpm.o H v~.w~ wuom.o H mm.m unNF.F H mm.oo m Np uom.o H om.m mmm.o H mm.mm mm~.o H m_.m mum.o H F~.eo o ow amom.o H um.m ppm.o H me.mm um“.o H mm.m amm.o H me.om c on amm_.o H om.m c_m.o H om.om mo¢.o H mm.F nmN.F H mm.mm o om ammo.o H mm.m ummw.o H mm.mm m~m.o H we. 1 m¢¢.~ H oa.mm o o— nmw~.o H um.m 4mm.o H NN.¢P mmm.o H oa.~- um¢.o H m¢.mm o o a x Am oo~-zm copwu be 4m 4 oopmsmxpom cmuzoa Hoccmu mszme> mm=Fm> mucmgmwewo LOFoQ copes: cowusuwumnam mo Fm>m4 . mamsu Hoccmu mo mm:_m> Lofiou m>euumwno new m>wuumnn=m cuoo tom cowumw>mn ntmncmpm new meme: .mm mpnmp N F 80 see_eeeeoee co _e>e_ 3m em deceeeeeeu Heeeee_em_m . xee_eeeeoea e6 Fe>ep 3, He eeeeeeeeee Heeeeceememee mo.o mm._ qo.c no.o __.o mo.o mm segue: ramm.c «*vw.w wc.o *m—.c *3mm.0 «*wm.P w mmpamwgm> mp.o mm.o mo.o Pp.o mF.o mm.o we pouch zuwpwn :mpqmuu< Pmmmcpzoz »He_enmwce mmmcqmwcu 50 mo; pmgmcmw wczuxmh Lo>m—e Lopou mo mwgmwm mmuczom menacm cam: mmopsppmu Lo\ucm Lawson poccmu mo meowuauwumnzm gym: umcmamgn maecu Hocgmo mo cowumaFm>m m>wuumnnzm com mucmwtm> 4o mmszmc< .om mpnmp 81 Another factor contributing to the overall color of the carrot chips was the Maillard reaction. Fresh carrots con- tain approximately 4 to 6% total sugar, mainly sucrose and glucose. High protein materials were also present in the chips, causing the Maillard reaction between the reducing sugar and amino groups during the frying and baking process. Crispness, Friability and Shear Press Means and standard deviations for crispness, friability, and shear press values are presented in Table 31. The shear press is a physical device which was used to measure the crispness and friability of carrot chips. The analyses of variance for shear press values revealed highly significant differences (p < 0.01) among variables (Table 28), while analyses of variance for crispness and friability (Table 30) revealed slightly significant differences at the 5% level of probability. The friability values decreased only slightly as the level of carrot powder substitution in- creased. However, crispness actually increased slightly as the carrot powder substitution increased. The reason for the differences were not greater in crispness and fri- ability among the variables could be because the level of baking powder was also increased as the level of carrot powder increased. They may have altered the dense cell structure of the carrot chips to produce a lighter texture. Shear press values indicated that the pounds of force needed to break a gram of sample increased as the level of 82 .Aemm_ .eeeesgv spe_ee666ta to Pesep Hm mcH Hm Hememmmeu appcmuwewcmem Ho: mew cmppmp 05mm we» as umpawcumcmaam mmmcm>< u w...m step m>wpnwtummu en» gave: memmanmcma cw cmumwp choa mpnwmmoa Fmpoem meowumoepamc m>mm co ummmm _ um~.N H Pm.FN nwo.o H mm.m mpm.o H mn.¢ 6 mm om~.~ H cm.mm nem.c H N¢.m mwp.o H mm.¢ m mm uumn.F H mm.¢m amm~.o H mm.m ammm.o H om.¢ e op onwo.~ H ¢P.~N nom.c H ~¢.m nnm.o H n~.e m NP moo.m H No.¢¢ nmmm.o H om.m ewe. H om.¢ o cc mm~.m H mo._e n-.o H mm.m amom.o H mm.¢ o om no~.m H mu.om amp.o H ce.m mmm.o H No.¢ o om uum_.m H mo.~m ammp.o H ~m.m mmm.o H mm.e o op ow.m H wo.om m¢_.o H mn.m w_.o H mm.¢ o o v I. am Em\eeeoe e_ m Ame oommzm H wmmta camcm a»? H mete mmmcamecu oopeumx_om cmczoa Hoccmu N wgauxme eoeezeeemezm to Pe>es Hoctmu mo m=Pm> mmmca temsm new maesu w&:uxm¢ Lon? Pmcomwmw>mb tLMUcwum Ucw mcmmz .Fm mpnmh 83 carrot powder and cellulose increased. This was probably a result of the dilution of the gluten-forming proteins which are responsible for dough extensibility and starch which contributes thermoplastic properties by the increased amount of carrot powder and cellulose. Addition of 10% egg powder and 10% Parmesan cheese into the carrot chip formulation caused further dilution of the main structural Components of the carrot chip. The dilution effect could result in a chip with a denser cell structure. Therefore, more rigid chips were obtained. Fewer small bristles were also found in these rigid chips. Mouthfeel and Flavor Means and standard deviations for flavor and mouthfeel are presented on Table 32. Analyses of variance showed significant differences for both flavor and mouthfeel scores (Table 30). The panelists indicated that the flavor scores of all the substituted carrot powder chips were higher than the control. However, as the level of carrot powder in- creased from 10 to 40% the flavor scores decreased slightly, nevertheless even at the 40% level the chips were preferred by the panelists over the control. The chips with carrot powder plus cellulose were considered more acceptable in flavor by the panelists than the chips with a comparable level of only carrot powder substitution. Cellulose slightly modified the distinct carrot flavor in a way more desirable to the panelists. The distinct taste of the carrot chips 84 Table 32. Means and standard deviations1 for flavor and mouthfeel of carrot chips Level of Substitution Carrot powder Sogfiaéggoc Flavorz Mouth-fee12 % 3 (8) (5) 0 0 5.63 0.34c 3.75 0 17a 10 0 6.33 0.35ab 3.83 0 19a 20 0 6.28 0.483% 3.70 0.25a 30 0 6.18 0 413 3.63 0.33a 40 0 6.05 0.38 3.32 0 39b 12 8 6.03 0.40b 3.63 0.24a 16 4 6.30 0.07ab 3.83 0 14a 22 8 6.40 0.26ab 3.93 0.18a 26 4 6.50 0 273 3.90 0.20a —__ 1Based on five replications 2Total possible point listed in parenthesis under the sensory characteristics abAverage superscripted by the same letter are not signifi- cantgy different at the 5% level of probability (Duncan, 1957 . 85 results from a combination of the following flavors: (l) the natural flavor from the carrot powder; (2) a nut-like flavor of pyrazine a compound which resulted from the Maillard reaction between carbonyl and a-amino groups of the carrot chip components; (3) flavors from added ingredients, such as garlic, sesame, egg powder, and Parmesan cheese, which not only add specific flavors, but appeared to complement the carrot taste. General Acceptability Means and standard deviations for general acceptability values are presented in Table 33. The analyses of variance of these data indicated significant differences among the variables (Table 30). Chips formulated with carrot powder received higher scores than the control chips. Combining cellulose with carrot powder produced chips with the highest acceptability scores. All the chips possessed good eating quality and acceptability. Since the carrot chips were a newly developed snack food, time was required for the taste panelists to adapt to the unique flavor of carrots. The sensory scores revealed that very diverse acceptability was obtained from the first two sections of panelists. Among 20 of the panelists, only 2 marked "like very much"; 6 marked "like slightly”; 4 marked "neither dislike nor like"; and 2 marked "dislike very much". The degree of acceptability increased markedly after the third session. Perhaps the higher scores resulted as the panelists became accustomed to the carrot flavor or less prejudiced toward eating 86 Table 33. Means and standard deviations1 for general acceptability of carrot chips Level of Substitution General Acceptability2 Carrot powder Solka-floc BW-200 % % (9) 0 o 6.60 i 0.41f 10 0 7.20 i 0.33c 20 0 6.97 i 0.3ode 30 o 7.17 : 0.36C 4o 0 6.93 i 0.31e 12 8 7.10 i 0.26d 16 4 7.32 : 0.32b 22 8 7.47 i 0.24a 26 4 7.50 i 0.21a 1Based on five replications 2Total possible point listed in parenthesis under the descriptive term a...f Average superscripted by the same letter are not significantly different at 1% level of probability (Duncan, 1957) 87 carrots as a snack chip. The level of substitution with carrot powder up to 40% produced a chip with good eating qualities and a high acceptability. The dilution effect of cellulose on the quality characteristics of carrot chips revealed a higher acceptability of color, texture, mouth- feel, and flavor than those chips without cellulose. How- ever, preference for carrot flavor intensity varied with different individuals. The snack food manufacturer could use various levels of carrot powder in chip formulations to produce a versatile carrot chip by modern extrusion tech— niques. Enzymatic Neutral Detergent Fiber (ENDF) Values Means and standard deviations for ENDF values of carrot chips are presented in Table 34. Analysis of variance indicated that highly significant differences (p < 0.01) for ENDF values occurred among variables (Table 35). ENDF con- tent values increased as the level of carrot powder and cellulose substitutions increased. The percentage of ENDF was greater in samples with cellulose substitutions than in those with only carrot powder replacement. This was because fiber concentration in commercial cellulose was much greater than in carrot powder. Southgate (1976) reported that dry carrots contain 28.6% dietary fiber, while commercial cellu- lose contains almost 99% pure fiber. Sesame seeds have 14.36% ENDF and bread flour 2.09% ENDF. Sesame seeds contri- buted a constant amount of ENDF since the percentage weight of sesame seeds was the same for each variable. Therefore 88 Table 34. Means and standard deviations1 for Enzymatic Neutral Detergent Fiber (ENDF) Analyses of carrot chips Level of Subst1tut1on gm ENDF Carrot powder Solka-floc ENDF per 02 of BW-200 carrot chips % % % O 0 3.13 i 0.05 0.89 10 0 4.20 i 0.04 1.20 20 0 5.27 i 0.05 1.50 30 O 6.34 i 0.04 1.81 40 0 7.43 i 0.04 2.12 12 8 11.44 i 0.03 3.26 16 4 9.08 i 0.02 2.59 22 8 12.57 i 0.05 3.57 26 4 9.47 i 0.05 2.70 1Based on five replications. All means are significantly different at 1% level of probability Table 35. Analysis of variance for Neutral Detergent Fiber (ENDF) values of carrot chips prepared with carrot powder and/or cellulose Source Degree of Freedom Mean Square of ENDF Total 44 9.52 Variables 8 52.37** Within 32 0.0006 **Significant difference at 1% level of probability 89 the total percentages of ENDF values for each variable were altered as the level of bread flour substitution with carrot powder and cellulose changed. Very little research has been reported on the composi- tion of carrots, particularly in terms of the carbohydrate constituents of carrots. Southgate (1976) reported that dry carrots contain 28.6% dietary fiber which includes 11.44% cellulose, 6.01% pentoses, 7.72% uronic acid, and 3.43% hexoses. Spiller and Amen (1976) reported that carrots con- tain 9% NDF and 9% pectin. Thus, carrots contain 18% true fiber and 50% of that true fiber is lost during NDF extrac- tion. The ENDF analyses value of carrot powder in this study was 12.88%. If 50% of water-soluble dietary fiber is lost during ENDF extraction as have been reported by Spil- ler et al. (1976), it can be concluded that in actuality the carrot powder could contain 25.76% dietary fiber. Each 10 gm of carrot powder could contribute as much as 2.5 gm of dietary fiber. Thus, the percentage of dietary fiber in the carrot chips ranged from 5.7 to 12.6% dietary fiber for levels of carrot powder substitution from 10 to 40% and 11.1 to 15.2% for carrot powder and cellulose combination replacement. Therefore, the real dietary fiber value for carrot chips in each variable could be 33% higher than the reported ENDF value. 90 Dietary Fiber Available From Commercial and Home-made Foods Means and standard deviations for ENDF value obtained from ENDF analyses of some commercially baked products and cereals as well as selected home-made, whole grains breads which were prepared for this study, are tabulated in Tables. 36 and 37. These data indicated that products made from brans and crushed whole grains contributed substantially higher amounts of dietary fiber. The ENDF percentages in cereals, corn chips, crackers, and European flat breads were significantly higher than in breads. While fruit-nut breads had moderate ENDF values, vegetable breads such as zucchini and carrot bread had low ENDF values. Among chips, Tor- tilla chips had the highest ENDF values, corn and potato chips had lower values and carrot chips had the lowest values. The fact that carrots had lower ENDF values than those of Tortilla chips, corn chips, and potato chips are due to the following reasons: (1) Tortilla chips are made from whole corn and tomato pulps. Whole corn kernels contain 2.1 to 2.3% crude fiber and 10% hemicellulose but contain no pectic substances (Inglett, 1970), while dry tomatoes con- tain 4.41% lignin, 6.72% cellulose, 4.15% pentoses, and 4.34% uronic acid (Southgate, 1976). Therefore, corn and tomato pulp together contribute at least 19% of ENDF, with less lost during ENDF extraction since corn does not con- tain water-soluble pectins; (2) Corn chips are made 91 ' Table 36. Means and standard deviations for Enzymatic Neu- tral Detergent Fiber Content in cereals and whole grain breads gm ENDF per serving Food Items % ENDF (1 oz) Cereals: Kellogg's All Bran 3 .06 .44 .71 Kellogg's Bran Buds 3 .84 .04 .64 Kellogg's Raisin Bran Flakes 1 .72 .15 20 Ralston's Wheat Chex 1 .85 13 .95 Kellogg's Frosted Mini-Wheats l 55 19 .86 General Mill's Wheaties l 57 Food Club Raisin Bran Flakes Grape-Nut Cereal Kellogg's Country Morning Nature Valley's Nature Cereals Total, General Mills Nature Valley Granola Cinnamon and Raisin Cereal C.W. Post Family Style Cereal Cap'n Crunch Crunchy Berries 00 C) 1+ 1+ 1+ 1+ 1+ 1+ 1+ 1+ 1+ 1+ 1+ 1+ U1 U1 d—J—J-ANNwww-DKDLO O .—l 00-h menmcaxdwowwhca-b 0'1 4:. N (I) _; (JO 0 CO OOOOOOOOOOOO b U1 0" 0‘ H- H- .4 G) —l 0 KO Whole grain bread: Rye Bran Bread Schwazbrot Pumpernickle Fig Bran Bread Stollen Awrey Heart Health Wheat Bread Apple Bread Bran Bread Rolled Oat-Nut Bread Oat Raisin Bread Banana Bran Bread Italian Rye Bread Raisin Bread, 80% Carrot Nut Bread Zucchini Bread Nwhmmmmmmwwo—Iww O (1) 1+ 1+ 1+ 1+ 1+ 1+ 1+ 1+ 1+ 1+ 1+ 1+ 1+ 1+ 1+ OOOOOOOOODOOOOO —'3 tom QQ—o—a—J—I—I—l—INNNwww 00 O 92 Table 37. Means and standard deviations for Enzymatic Neu- tral Detergent Fiber Content in crackers, European flat breads, cookies, snacks and other food stuffs gm ENDF Food Items % ENDF per serving (1 oz) Crackers and European flat bread: Siljan Swedish Rye CriSpbread 36.27 i 0.31 10.34 Idea Flat Bread, Norwegian 28.23 i 0.28 8.05 Rogga 25.40 i 0.36 7.24 King's Crisp Bread 25.21 i 0.22 7.24 Crisp Bread with Linseed 22.44 i 0.09 C.40 Mors Flatbread 17.77 i 0.15 5.05 Crisp Bread with Sesame 16.44 i 0.26 4.69 Triscuit Whole Wheat 14.67 i 0.42 4.11 Hol Grain Natural Rice 5.97 i 0.18 1.70 Wheat Square Crackers 5.41 1 0.41 1.54 Honey Sorghum 4.76 i 0.29 1.36 Hearty Wheat Snack Cracker 3.67 i 0.38 1.05 Cookies and snacks: Doritos Tortilla Chips 32.44 i 0.46 9.25 Sesame and Bran Sticks 16.10 i 0.12 4.59 Corn Chips 14.11 i 0.04 4.02 Potato Chips 12.64 i 0.28 3.60 Sesame Buds 10.85 i 0.12 3.08 Nature Vallye Granola Bars 8.09 i 0.10 2.31 with Coconut Old Fashioned Oatmeal Cookies 5.43 i 0.16 1.55 Fig Bar 4.25 i 0.16 1.21 Other food stuffs: Red Wheat Bran 40.81 i 0.12 White Wheat Bran 39.77 1 0.14 Wheat Germ 24.26 i 0.14 White Sesame Seeds 14.36 i 0.10 Carrot Powder 12.88 i 0.05 Jiffy Bran Muffin Mix 9.67 i 0.08 Defatted Soy Flour 7.31 i 0.10 Rolled Oat 5.63 i 0.28 Bread Flour, General Mills 2.09 i 0.04 93 primarily from corn and contain at least 12% ENDF in a dry matter base; (3) Potato chips are entirely made from pota- toes in which some starches have been removed before deep- fat frying. According to Southgate (1976) potatoes contain 6.24% lignin, 7.02% cellulose, and 6.24% hemicellulose based on dry weight; (4) Carrots contain 11.44% cellulose and 17.16% noncellulosic dietary fiber (mainly 7.72% uronic acid, 6.01% pentoses, and 3.43% hexoses). Most of the non- cellulosic dietary fiber components are soluble in water, and therefore, at least 50% of dietary fiber in carrots is lost during ENDF extraction due to the composition; (5) Car- rot chips are made from 5 to 18% carrot powder, 4% sesame seeds, 26 to 43% wheat flour, and 2 to 4% cellulose. Carrot chips, therefore, contain porportionally less water-insolu- ble fiber components than other chips. Therefore, carrot chips contain less ENDF than other chips. However the water-soluble constituents; pectin, uronic acids, pentoses, and hexoses, found in carrots are considered excellent bulking and ion-exchange agents making carrot chips feasible carriers of vegetable dietary fiber. SUMMARY AND CONCLUSIONS The purpose of this study was to investigate the effects of substituting varying levels of carrot powder for bread flour on the physical and sensory quality characteristics of carrot chips. Cellulose was used to modify the intense carrot flavor, color and texture of the carrot chips con- taining the higher levels of carrot powder substitution. Enzymatic Neutral Detergent Fiber Analyses were carried out for the carrot chips as well as other cereal and grain products to determine their dietary fiber contributions. It is hoped that this research will provide more definitive information on sources of dietary fiber. Carrot chips were prepared from wheat bread flour using a modified wheat chip formulation with increasing substi- tution levels of carrot powder. Substitution levels in— cluded 10, 20, 30, and 40% carrot powder; 12 and 22% carrot powders blended with 8% cellulose; and 16 and 26% carrot powders blended with 4% of cellulose, respectively. Fresh carrots were dehydrated and dried in an air-blast oven, the dry carrots were then ground with a cyclone mill to the same particle size as the bread flour to facilitate rehydration and to provide consistent dough sheeting. Both subjective and objective methods were used to evaluate the quality characteristics of the carrot chips. 94 95 The subjective evaluation included (1) appearance (color and bristles), (2) flavor, (3) texture (mouthfeel, crispness and friability), and (4) general acceptability. The objective evaluations included moisture, crispness using the A110- Kramer shear press, and color using the Hunter Color Dif- ference meter. Chemical analyses of the dietary fiber content of carrot chips, and other cereal products, were used to determine foods rich in fiber content. Objective measurement of the quality characteristics of the carrot chips indicated that the moisture level of the raw dough increased as the levels of carrot powder and cel- 1ulose substitution increased due to additional water in the formulation, the different levels of substitution did not affect the final moisture Content of the carrot chips. The natural orange yellow color of carotenoids in the carrots resulted in chips that were slightly darker with higher redness and yellowness values. Test panelists, however, scored those chips similarly. Carrot powder substitution made chips slightly crisper and a little less friable. As the level of carrot powder increased, more force per gram was required to shear the carrot chips. Corrot substitution reduced the gluten available extensibility of the dough. Nevertheless, the chips produced had acceptable crispness and friability scores and were felt to be suitable for packaging without excessive breakage. 96 Carrot powder and cellulose substitution improved the flavor and general acceptability scores of the chips while mouthfeel was unaffected except for the variable with 40% carrot powder substitution. The carrot chips were well-liked by the panel. Using cellulose along with the carrot powder produced the most acceptable chips. Addition of sesame seeds to the chips not only provided nut-like flavor but also contributed a substantial amount of dietary fiber. Increasing the substitution levels of carrot and cel» lulose resulted in increased ENDF values of carrot chips. Increasing ENDF did not impair the eating quality of carrot chips. 0n the contrary, replacement levels up to 40% car- rot powder and 8% cellulose in the chip formulation produced good quality and acceptable carrot chips. Moreover, carrot chips prepared from the blended carrot powder and cellulose had the best quality characteristics among variables evalu- ated. Substitution of carrot powder alone provided from 1.2 gm of ENDF per ounce at the 10% level to 2.12 gm ENDF at the 40% substitution level. The combination of 12% carrot powder and 8% cellulose contributed 3.26 gm ENDF per ounce, and the largest amount of fiber per ounce in the various chips was found in the 22% carrot powder and 8% cellulose chips which contained 3.57 gm per ounce serving. Smith (1974) reported that the total snack market in the United States has passed the $5 billion figure per annum and responsible estimates indicate this will reach 97 $8 billion in annual sales by 1980. Snack can be specially formulated as high protein, high energy, or high dietary fiber foods. Carrot chips contained approximately 7.7 to 11.5% protein, 30% fat, and 4.2 to 12.6% ENDF. Thirteen cereals evaluated for their dietary fiber com- position ranged from 3.8 to 34.1% ENDF. Six of these cereals had over 10% ENDF and would contribute from 3 to 9 gm dietary fiber per one ounce serving. The fourteen whole grain and vegetable quick breads analyzed were found to contain 2.0 to 13.7% ENDF. These breads could contribute from 0.6 to 3.9 gm of dietary fiber per one ounce serving. Eight cookies and snack foods contained 4.3 to 32.4% ENDF and would contribute from 1.2 to 9.3 gm dietary fiber per serving. Twelve types of crackers and European flat breads contained 3.7 to 36.3% ENDF with contributions of 1.1 to 10.3 gm dietary fiber per serving. Of the foods analyzed, All Bran, Bran Buds, Doritos Tortilla Chips and Siljan Swedish Rye Crispbread contained over 30% ENDF while several other European flatbreads analyzed had 20% ENDF. In conclusion, several commercial and homemade products have been found to contain substantial amounts of dietary fiber. In addition, a carrot chip has been formulated which is of good quality and is a significant source of dietary fiber. If dietary fiber becomes a recommended nutrient, the more sources avtilable for selection of this nutrient, the more likely people with diverse food habits will meet their requirement. PROPOSALS FOR FUTURE STUDIES A study of the effect of combinations of roasted bran flakes, coconut residues, dry fruits, and nuts in snack bar product formulation should be undertaken. An investigation such as substituting carrot powder and cellulose in frozen egg-roll skins and other pastry products is recommended since carrots are stable at low temperatures. Fortification of cereals, candy bars, popcorns, and poprices with seaweed films (Ze-Tsi) or dry vegetables is recommended. These seaweed films are rich in cellulose, hemicellulose, gums and mucilages. Higher levels of carrot powder and cellulose substi- tutions should be studied. Increasing the levels of carrot powder up to 50% with a maximum of 12% cellu- lose might produce chips of good quality with higher dietary fiber values. The dense structural charac- teristic can be solved by adding slightly higher levels of a leavening agent and/or selected emulsi- fiers to improve the dough consistency. Techniques for preventing the oxidation of carotene in carrot substituted products need to be developed. More efficient methods of dietary fiber analyses on the combined daily diets should be developed. 98 APPENDIX CARROT CHIP SCORE SHEET Please check the word which best describes how you feel about these products - just check with "+'" for each product. Appearance Characteristics Product Number Color entirel olden n r go en brown w t, 1i 1 d rn d br st e burne dark br wn ver burne Shape like ver much mo erate ke s ht ne h r nor s e Bristle many bristles evenly distributed few bristles evenly distributed few bristles unevenly distributed 1 no bristle Raw-IS 99 100 Texture Characteristics Friable extremel ver eas s t m era e ar Crispy extr mel ver mod ratel s i htl not so Mouthfeel ver leasant easan ne t er ou nor r s t ou an r Product Number ou r t r 101 Flavor Characteristics Product Number 6 extremel ver muc mo era e s an tas e ess US ne S mo era e VEY‘ lllUC EX reme ex reme ver muc mo era e ver 5 ll ne er e nor flavor dislike s e s s e ver muc s e ex reme Detectable flavor or aroma - Please describe the detectable flavor as much as you can 102 General Acceptance Product Number 1 I) 9 like extremely 1 like very much like moderately like slightly neither like nor dislike dislike slightly :63 dislike moderately 2 <:::::> dislike very much Mllll" dislike extremely Suggestions - Gratefully Welcome! 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