A. AA. —- -,v -. ml AL. in -_ (“n .A‘ —-1..-. 'W'“-'"."f‘?.'z V-Y_..'. ‘7 ~--‘ - Syn 2|, ‘4 «.3. .14. ‘ _ . "-,.'_7.'.‘, r. . £1331, t": . {-1. ‘i' .. :1 '5‘?" din-A ’ a 11"v”«. ‘9. "Ruféc' : u Inc'- ‘ \- .7 '11:... ~. - - 51.1. 1 ‘3' 3311;.“ ' '97 .9...” "r'n'i'k ' ”'1:- 1...'-;*‘1;.1 $3,311 “111113111111 1 313511 . . 1. ‘ .‘u— n «vi 5’ .17“: RE: . . ..1 : quit -1 45.31:" if -_m 1-413 $5. 1 “in-w. : “5.x,“ . 3.24:2"; ""v" . 3— 13‘.) ‘ . ‘ Q .3 ifiy J. 4'." ”’1; i. O}? .v . .11.?” . ‘(ra{ JV , .71 {'1 711%,;3g: ‘13,”. .3}: 5.7 «.2. .1. .‘ 51": " u If 1.521.}! . '1 31 :1. [-9- w ‘1 t. ”.”${' #2" V}. 91.1.5." ..ux_ {a L ‘ 15:14] ‘ ‘ . 1:41. . 2. $51“ 1;, W.. '- . .‘ \ ? 1..1-:.;- 1 151;!“ . 1 1 . 11;.“ "1' 1 "$233 M . , b u n . 1 fax-.1": (1‘: ‘ .21? '(1’13'.\’- .1; :52" “$15.. . 259' ”Cs {1‘3 1 l h. .. 31:11.1. ,fl'r' .9: )1 . .. .J.1 '1' r "‘“ fig; 2:23,! & Ilfigv'.’ (affix?! ""1 ~ 1 1 . r :11. , 3M? '21! ‘ ‘15-.11‘ 1 JV. - i 3357'”! " " 1/..Il.r'y . 7 l1 1.1“. {’43. ///, 31,54, * 111-1J1/1u/1’1/x; I":.' {£2 ii” 5,: 31;,“ 3:... }}/.:;fl’?, ,x , 1,.“ -/I. . 5’1"“ ‘ £10,221” .. rffi’fgllul ‘3};ZIIA.J4: ET" I 71:9!” '{I .1“qu J // J’fi' 9.515%] 1/ ,fié'f' ‘3? :’ " ”1’ 4:1 111"” .1 .H J". filil'q l'! ’lj'lT'JIlvl /-:::/1'.,,’17I' '1}: ' r11}:",:/r,r;:r1,é;7,1/,J; fr‘ 171.1337}; '1 111,15. 4;"! J" «ff/51“; I It... } '1.,”1'1"'1':v ,, - 11312,. d133,. 9 11 193119111991.“ 35am? ,/ 1. . " J ,1' 1113531711!"-’;:‘611.;;159/i’7u"4’/:.; 1.1"”??? ~11 2-1 1 - -, W112.» 1 ,., ‘ ‘ ' 1%"??? “I; 4?, £7" 3;” 1/44 1 “j, ’1 111’.- ;:'.1é{n?f;v" . 1,1111. .. q. {291/ f!" J 1, 4..., 1:1,», - n ”-3,”; ' 0", £357 Lia/zit”! f” "V 1 ' J.r /' /" “11"”??? ' '13,”! ' ' 1. '1' x.” J' ' ..-u“' ' lr/ fil7‘ln fl 4;!" ‘."')fi :1:- v 1111.- : _J LIBRARY Michigan State University This is to certify that the dissertation entitled Mathematical Modelling of Thermal Gelation of Myofibrillar Beef Proteins and Their Interaction With Selected Hydrocolloids. presented by Carlos Antonio Lever—Garcia has been accepted towards fulfillment of the requirements for Ph.D. Food Science degree in {m . ' W Major professor Date W ///l /?g MSU is an Affirmative Action/Equal Opportunity Institution 0-12771 MSU LIBRARIES __ RETURNING MATERIALS: Place in book drop to remove this checkout from your record. FINES will be charged if book is returned after the date stamped below. MATHEMATICAL MODELLING OF THERMAL GELATION OF MYOFIBRILLAR BEEF PROTEINS AND THEIR INTERACTION WITH SELECTED HYDROCOLLOIDS. BY CARLOS ANTONIO LEVER-GARCIA A DISSERTATION Submitted to Michigan State University In partial fulfillment Of the requirements for the decree DOCTOR OF PHILOSOPHY Deparment Of FOOd SCIODCC and Human Hutritlon 1988 507'3t/u5 ABSTRACT MATHEMATICAL MODELLING OF THERMAL GELATION OF MYOFIBRILLAR BEEF PROTEINS AND THEIR INTERACTION WITH SELECTED HYDROCOLLOIDS. BY CARLOS ANTONIO LEVER-GARCIA This study was designed to prov1de the experimental base of a proposed mathematical model for predicting thermally-induced gelation of myofibrillar beef proteins and their interaction with selected hydrocolloids. Four connercially available vegetable gums were evaluated. These hydrocolloids were carrageenan. guar. locust bean and xanthan gums. The mathematical model was designed to predict the gelation of myofibrillar beef proteins as a function of the time-temperature history of the process and.the protein concentration on a dry basis. The thermally induced gelation was measured as the Instron back-extrusion apparent VISCOSItY. A model myofibrillar protein system '38 utilized. CARLOS ANTONIO LEVER-GARCIA The model system was a solution of extracted myofibrillar beef proteins. Protein solutions were heated at 54. 64, 70. 80 and 85 °C. The time-temperature history of the process, the back—extrusion apparent viscosity and the model variables were calculated by a combination of commercial software and computer programs developed specifically for this experiment. It was found that under the conditions of this study. three terms of the model formerly reported as constants (A'.a and a) were actually functions of the protein concentration. These mathematical relationships were developed and integrated into the basic model. The modified mathematical model was found to predict (R3 from.0.88 to 0.97) the heat-induced gelation and the change in water holding capacity of myofibrillar beef proteins as a function of the time-temperature history of the process and the protein concentration (dry basis). It was hypothesized that vegetable gums contribute to the framework of the thermally-induced protein gels. Correlation between experimental and predicted gelation values of gels from carrageenan. guar and locust bean gums with.myofibrillar beef proteins (R2 from 0.85 to 0.91) CARLOS ANTONIO LEVER-GARCIA support this premise. As predicted by the mathematical model these protein- hydrocolloid gels had a higher gel strength and water holding capacity than the control. Under the conditions of this experiment xanthan gum was found to inhibit gelation. However this protein-gum solution had the best water holding capacity value among all experimental units. To my Wife DELIA GUZHAN DE LEVER for her love. support. 1‘1an WOPK and patience during my doctoral studies and those long long winters. To my son CARLOS RODRIGO and my daughter MARIANA DELIA who have been the light of my eyes and the Joy of my spirit. ACKNOWLEDGMENTS A special note of appreciation is given to Professor James F. Price chairman of my doctoral committee for his guidance. patience and support. His dedication as scientist was a source of continuous inspiration during my doctoral studies. To Professor Charles Cress who taught me a new way of thinking and open my eyes to the meaning of experimental design. To Dr. Ron Morgan who taught me what mathematical modelling is all about. To Drs. H.E. Zabik. A.H. Pearson and A. Booren, who also served in my committee. thank you very much for their assertive advice. A1 DI“. Carlos Escandon D. una nota muy especial de agradecimiento P01" 81 apoyo proporcionado a 10 largo de mis estudios doctorales. TO Fernando OSOPIO who helped me write the computer programs and WithOUt whose help it would not have been POSSIDIQ to find the solution for the thermal equations, muchas [111161188 SPECIES I . V1 For the financial assistance without which these studies could not have been possible, I would like to thank the Goverment of my country MEXICO through.the ConseJo Nacional de Ciencia y Tecnologia (CONACYT). also the Asociacion Hacional de Universidades e Institutos de Educacion Superior (ANUIES) and the Universidad Iberoamericana. Vii TABLE OF CONTENTS Page LIST OF TABLES . . . . . . . . . . . . . X LIST OF FIGURES . . . . . . . . . . . . . . XI INTRODUCTION . . . . . . . . . . . . . . . 1 REVIEW OF LITERATURE . . . . . . . . . . . . 5 Properties of Meat Proteins 5 Sarcoplasmic Proteins 6 Myofibrillar Proteins . 7 Tropomyosin Troponin Complex 9 Cytoskeletal Proteins . . . . . 10 Connective Tissue Proteins . . . . . 11 Role of Myofibrillar Proteins in Gelation . . . . 12 Gelation of Proteins . . . . . . . . i4 Mechanism of Protein Gelation . . . . i7 Mechanism of Gelation of Myofibrillar Proteins . . 20 Effect of Temperature in Gel Strength . . . . . 25 Theoretical Basis of the Mathematical Model . . . 27 Concentration Effects . . . . . . . 28 Rheological and Kinetics Background . . . . . 29 Characteristics of MydrocoIIOids . . . . . . . 36 MATERIALS AND METHODS . . . . . . . . . . . . 41 Experimental Design . . . . . . . . . . . 4i Experiment I . . . . . . . . . . . . 41 Meat Sample Preparation . . . . . . . 4a Isolation of Myofibrillar Proteins . . . . . 48 Heat Treatment . . . . . . . . . . . . 43 Gel Strength . . . . . . . . . 44 Evaluation of the Thermal Process . . . . . .45 Determination of Activation Energy . . . . . 51 Experiment 11 . . . . . . . . . . . . . 58 Methods of Analysis . . . . . . . .53 Determination of Water Molding Capacity . . . . 53 Buffer Preparation . . . . . . . . . . 54 Protein Determination . . . . . . . . . . 54 Statistical Analysis . . . . . . . . . . 54 Computer Programs Utilized . . . . . . . . 55 Program Rodrigo . . . . . . . . . . . . 55 Program Delia . . . . . . . . . . . . 56 Program Mariana . . . . . . . . . . . . 56 V111 Page RESULTS AND DISCUSSION . . . . . . . . . . . 64 Determination of Activation Energy . . . . . . 64 Determination of (a) . . . . . . . . . . . 79 Determination of A' . . . . . . . . 88 Test and Verification of the Model . . . . . . 93 Test of the Model . . . . . . . . . . 93 Verification of the Model . . . . . . . . 96 Effect of Vegetable Gums . . . . . . . . . 102 SUMMARY AND CONCLUSIONS . . . . . . . . . . . 115 BIBLIWRAPHY I O 0 0 O 0 0 O O Q I 9 0 O 116 APPENDICES . . . . . . . . . . . . . . . 128 Appendix A. List of computer program Rodrigo . . . 128 Appendix B. List of computer program Delia . . . .135 Appendix C. List of computer program.Mariana . . . 140 Appendix D. Experimental values of Y’ and TTH utilized in testing the model (Figure 13). . . . . . . . 155 ix LIST OF TABLES Table Page 1. Thermally induced back-extrusion apparent viscosity (Y’) for the time range of 30 to 350 sec and for five different temperatures . . . . . . . . . . . . 66 8. Calculated constant values for modelled experimental data cooked to five different temperatures . . . . . . . . . 58 3. Time of cooking in seconds required to produce selected thermally induced apparent viscosity for five different temperatures . . 69 4. Estimated values for Ea (cal/mot) for different Y's and temperature ranges . . . 71 5. Statistical analysis of the linear regression of experimental Y’ values and corresponding TTH values. Ea utilized was 29,500 cal/mol . . . . . ,. . . . . . 76 6. Statistical analysis of the linear regression of experimental Y' values and corresponding TTM values. Ea utilized was 20,000 cal/mol . . . . . . . . . . . 81 7. Calculation Of (a) and Kt values using an average Of 20 TTH values Ea used was 20,000 cal/mol . . . . . . . 84 8. Calculated values of equivalent protein concentration. a and A' for selected gum-protein combinations . . . . . 109 Figure 10. 11. 12. 13. 14. LIST OF FIGURES FlOW diagram Of computer program Roarigo o o o o o o o 0 Flow diagram of computer program Delia O 0 O 0 e O o O 0 0 Flow diagram of computer program Mariana . . . . . . . Estimation Of activation energy range for five temperatures and three thermal-induced apparent Viscosities correlation Of Y' values Obtained in the temperature range Of 54 to 84 OC and- their estimated TTH . . . . . . . Relationship between experimental values of Y' and the Log of TTH . . correlation Of Y' values Obtained in the temperature range of 64 to 84°C and their estimated TTH . . . . . . . correlation between G and (a) Plot of o versus R2 for five protein concentrations . . . correlation between G and protein concentration (d.b.) Correlation between protein concentration and Y' . . . . . . Correlation between protein concentration and A' . . . Experimental Y' values for temperature range Of 54 to 54 0C Versus values predicted DY the TTH model . . Experimental Y' values for three different protein concentrations versus values predicted.by the TTH model . . 81 Page 57 58 60 7O 75 77 60 85 87 89 91 98 94 97 Figure 15. 16. 17. 18. 19. 200 21. 220 Dependency Of water release for two protein over time Of cooking. concentrations . . . . Experimental water release values versus values predicted DY the m mOde l 0 0 0 0 0 Experimental Y’ values for carrageenan-protein solution and values predicted by the TTH model Experimental Y’ values for guar-protein solution and values predicted by the TTH model . . . Experimental Y’ Values for locust-bean-protein solution and values Predicted by the TTH model Experimental Y' values for xanthan-protein solution and values predicted by the TTH model Effect Of protein gum combination on a O 0 O O O 0 Water released by four gum- rotein combinations (75 min at 70 xii C) Page 100 101 104 105 106 107 110 111 INTRODUCTION The thermal gelation of myofibrillar beef proteins is an important phenomenon which takes place in all heat processed meats products. These series of chemical reactions are one of the major factors affecting the final sensory attributes Of meat products. Men learned to process meat products by this mechanism in ancient times. Egyptian hieroglyphics found in pyramids are the first recorded use of manufactured meat products. The great Greek philosopher and historian Homer describes in “The Iliad" how the Greek soldiers. during the siege of Troy. produced manufactured meat products by mixing meat pieces with spices and salt and stuffing them in goat stomachs before cooking. In the centuries that followed. men learned to modify the end-products of this thermal ly-induced gelation of meat proteins by trial and error. However. these changes were not accompanied by an understanding and a control of the chemical reactions responsible for this gelation. It was not until this century that knowledge about gelation reactions began to appear in technical literature. with most of the work concentrated in the last decade. It is now known that protein-protein interaction is the functional event which is related to the structural integrity of meat products through orderly heat-induced protein aggregations. that myofibrillar proteins play a major functional role. and that the complete myosin molecule is necessary for attaining appreciable continuity and strength in the protein matrix. All factors that affect myofibrillar proteins will affect the final texture and the quality of end products of the thermally induced reactions. Some factors that are known to affect this reaction are pH. type and concentration of salts. ionic strength. concentration and type of protein and time and temperature of cooking. The characteristic Viscosity of a thermally produced protein gel is considered a measure of the extent of gelation. and therefore. a function of the same factors that affect protein-protein interactions. During commercial meat processing operations several factors remain constant e.g.. pH. concentration and type of salts. However protein concentration and the time temperature history of fine process is unique to each.batch. and.therefore it was considered.that a mathematical model was needed to predict the final product of this thermally induced protein gelation as a function of the protein concentration and the time temperature history of the process. If such a model could account for the overall time temperature history of the process and the change in protein concentration. it could greatly reduce research time and costs. and therefore facilitate and decrease expense of food product development. A new type Of meat product that has been proposed for development is a IOW fat product. However fats in meat products have several functional properties. e.g.. they are a reservoir for flavor compounds and they contribute to the structure and texture Of the final product. Therefore. reducing the fat content may alter the product quality. To maintain the beneficial effect of fats in meat products several compounds may be necessary. Among these are the vegetable polysaccharides gums which seem to have several advantages. Polysaccharides gums are a group of chemical compounds that are extensively used in the food industry to regulate viscosity. as texture modifiers. and to form gels. The objectives of this study were 1. To develop a mathematical model that predicts the thermally induced gelation of myofibrillar beef proteins as a function of the protein concentration and the time temperature history Of the process. 2. To apply the model developed to the thermal gelation of selected combinations of vegetable gums and myofibrillar beef proteins and verify its validity. L ITERATURE REV I EW Gelation of proteins is an important phenomenon which takes place in all fabricated meat products during thermal processing. This tacky-sol transformation of meat proteins to a gelled state results in formation of the ultimate three-dimensional interlinked protein network. This phenomenon involves both intramolecular (conformational) and intermolecular changes in proteins. The protein network physically (due to capillarity) and chemically (due to noncovalent bonding) stabilizes water and physically or structurally restrains dispersed fat (in comminuted.meats) from rendering (Schmidt 9; l. 1981; Acton _e_t l. 1983; Gossett _; _3. 1984). This review will focus on (1) the main factors that affect gelation (meat proteins and chemistry and mechanism of protein-protein interaction). (2) the basis of a proposed mathematical model for predicting and (3) general characteristics Of selected vegetable gums. Progerties 2: Meat Proteins The composition of lean meat can be approximated in a broad sense as 75x water. aox protein. 3x fat and ex other substances. The aoz protein. calculated from.6.25 times percent nitrogen. includes 1 to 1.5% non-protein nitrogeneous substances. such as amino acids. nucleotides. creatine and traces Of Other nitrogeneous compounds (Schut. 1976; Forrest _g __1. 1975; Schmidt. 1957). Muscle proteins have been traditionally classified into various categories on the basis Of distribution. organization. solubility and function in the living muscle. Roughly they can be divided into three groups. 1. e.. the sarcoplasmic proteins soluble in salt solutions Of lOW ionic strength (< 0.1), the myofibrillar or structural proteins. WhiCh are soluble in concentrated salt solutions (ionic strength Of 0.5 to 0.5) and the connective tissue proteins. WhiCh are insoluble in bOth. at least at low temperatures (Szent-Gyorgyi. 1951; Perry. 1956). Sarcoplasmic Proteins The soluble proteins of the sarcoplasm located within the sarcolemma are referred to as sarcoplasmic proteins. Among them some albumins and.the so called myogens. to which belong most of the enzymes of glycolitic pathway. are the real water-soluble proteins (Schut. 1976). The other fractions of sarcoplasmic proteins are soluble in low salt concentration (ionic strength <=0.1). The recent trend is to partition the sarcoplasmic proteins into four fractions by sucrose gradient techniques involving ultracentrifugation. They include a nuclear fraction. a mitochondrial fraction. a microsomal fraction and a cytoplasmic fraction (Asghar and Pearson. 1980; Bodwell and McClain. 1971). About 100 different proteins are known to be present in the sarcoplasmic fraction (Scopes. 1970) which constitutes about 30 to 35% of the total muscle protein or about 5% of the weight of muscle. Despite their diversity sarcoplasmic proteins have some common physicochemical characteristics. They are globular or rod shaped in conformation. have low viscosity. have isoelectric point between pH 6.0 and 7.0. and.have molecular weights in the range 30.000 to 100.000 daltons (Bendall. 1964). Mzofibrillar Proteins The salt-soluble proteins which compose the myofibrils within the muscle fibers are collectivelly defined as the myofibrillar proteins. They constitute about 55 to cox of the total muscle protein or 10% of the weight of the vertebrate skeletal muscle (Lawrie. 1974). The major proteins in this category are the myosin-actin-actomyosin group. the tropomyosin-troponin complex. the minor myofibrillar components and the cytoskeletal proteins. Based on their physiological functions in muscle. myofibrillar proteins can be classified into two subgroups: (1) the contractile proteins and (2) the regulatory proteins. The myofibrillar proteins. myosin and actin. which.are directly involved in the contraction-relaxation cycle Of live muscle are termed "contractile". Myosin and actin are the major components of thick and thin myofilaments. respectively. Some of the salient characteristics of contractile proteins were published by Bandman (1987). Myosin is the major constituent of the thick myofilaments of the sarcomeres. It accounts for approximately 35% of muscle protein and is the most abundant of all proteins found in muscle (Manson and Lowy. 1964). It is a thread-like molecule with.a high length-to-diameter ratio (40:1) having a molecular weight of 470.000 to 500.000 daltons (Frederiksen and Moltzer. 1968). Actin is the major constituent of the thin myofilmment and accounts for sex of the myofibrillar protein (Portter. 1974; Yates and Greaser. 1983). It exists in two forms: globular (G-form) and fibrous (F-form) depending on environmental conditions (Steiner _t _3. 1952). At physiological concentrations of salt. globular G-actin polymerizes to form filaments (F-actin)which can interact with myosin filaments to produce mechanical energy for biological movements (Bandman. 1987; Miyanishi and Tonomura. 1981; Pollard.gt a}. 1981). When actin is extracted with water from.muscle tissue it is obtained in the globular form. having a molecular weight of from 44.000 to 49.000 daltons (Sender. 1971; May gt 3;. 1973). Since the actin filaments have no defined length F-actin does not have a determined mo lecul ar weight. In muscle. myosin and F-actin are present in a more or less complexed form called actomyosin. Actomyosin is the structural component which is responsible for contraction and relaxation in muscle of living animals (Granicher and Portzehl. i964). Tropomyosin-groponin Compl ex These myofibrillar proteins. which.are not directly involved in cross-bridge formation but play a role indirectly in the contraction-relaxion cycle. are called regulatory proteins (Maruyama and Ebashi. 1970). Tropomyosin and troponin together account for 9.5x and 12.05% of the muscle proteins and.have molecular weights of 36.000 and 70.000 daltons. respectively (Forrest g; 3;. 1975; Porzio and Pearson. 1977). Both.of these proteins are located in the groove of the actin filament and play an important role in the control of muscular contraction. in particular as a regulating system.under the influence of calcium ions (Murray and‘Weber. 1974). During the last few years a number of new proteins have been discovered in skeletal muscle. Guantitatively. must of them are insignificant. but are believed to be involved with.the regulation of the filamentous structure of myofibrils. and hence they have been classified as minor regulatory proteins. However. a precise function for many of 10 them is not yet clear. According to Asghar g; _l; (1985) these proteins are distributed in different parts of the ultrastructure of filaments such as the M-line (e.g.. M-protein or myomesin). A-band (e.g.. C-. F-. M-. I- and x-protein). z-disk (e.g.. o-actinin. z-nin. and Eu-actinin). and I-band (e.g.. B-actinin and y-actinin). Cytoskeletal Proteins Several researches have reported the existence of longitudinal filaments other than those of actomyosin. Those filaments look as if they are connecting the thin filaments on either side of the z-line. Some researchers denoted them as S-filament (Maruyama. 1980). Other filaments were also seen as if they were connecting the edges of the thick filaments to the z-line. and Sjostrand (1962) designated them as gap filaments. Locker and Leet (1975) also supported the existence of gap filament in the skeletal muscle. while other workers used the term T-filaments in their description (Maruyama. 1980). According to Wolosewick and Porter (1979) a three-dimensional filamentous lattice connects most of cytoplasmic structures. As the average diameter of these filaments is about 10 nm. which is between that of actin (6 nm) and myosin (15 nm) filaments. they are referred to as intermediate or 10 nm filaments (Bornstein and Sage. 1980; Gard g; 3;. 1979; Lazarides. 1982; Price and Sanger. 1979; Price and Sanger. 1980; Steiner gt 1. 1952; Wang and Ramirez-Mitchell. i983). Chemically. intermediate filaments 11 differ from contractile and regulatory proteins in many respects. and morphologically they resemble collagen fibers. which in contrast. exist extracellularly. Since the intermediate filaments are believed to strengthen the architecture of myofibrillar system in muscle. they have also been named cytoskeletal or backbone proteins (Granger and Lazarides. 1978; Obinata _5 _l. 1981). These proteins represent longitudinal intrafibrillar and transverse interfibrillar bridges (Gracia-Nunzi and Franzini-Armstrong. 1980). The proteins which can tentatively be included in this group are titin (or connectin). nebulin. desmin (or skeletin). vimentin and symentin. Some important properties of cytoskeletal proteins are published by Asghar t al. (1985). Connective Tissue Proteins The interstitial space Of muscle cells (syncytia) contains three proteins. namely. collagen. reticulin and elastin. WhiCh are fibrillar in nature. Collectively they are called connective tissue WhiCh, in fact. also contains some globular mucoprotein and non—protein components such as lipids and different mucopolysaccharides (hyaluronic acid. chondroitin sulfate A. B and C. keratosulfate. heparitin sulfate and.heparin in the form Of galactosamine or glucosamine). However. the extracellular proteins around 12 individual muscle fiber consist mainly of fine reticular and collagenous fibers which constitute the endomysium layer (Bendall. 1964). Collagen consists of a triple helix that contains a higher hydroxyproline content than any other meat protein. Collagen fibers shorten to about one-third.their original length when heated to 70 00. At a temperature of about so 0c or higher collagen is converted into gelatin. Reticulin. resembling collagen in many respects. does not produce ge l atin on heating. Elastin is a rather unique protein because it contains the uncommon amino acid residues desmosine and isodesmosine. These amino acids are involved in the crosslinking of the polypeptide chains and give elastin its characteristic elastic properties. Unlike collagen. elastin is not decomposed by heat. contains very little hydroxyproline. has very little swelling ability and is extremely resistant to acid and alkali (Bendall.1964). Role 2: Myofibrillar Proteins i; Gelation The presence of salt-extractable myofibrillar proteins has been shown to be necessary for satisfactory binding in both emulsion and restructured.meat products. Using model emulsion systems. Acton and Saffle (1969). Miller 3; pl. (1980) and Randall and Voisey (1977) showed that increasing 13 the proportion of salt-extractable myofibrillar proteins produced a concurrent increase in binding quality. A similar effect was observed by Acton (1972) and Siegel 53 al. (1978) With sectioned and formed products. In addition to the research done on the binding of myofibrillar proteins as a group. work has been carried out to determine the role of the individual myofibrillar proteins in binding. Much of the initial work in this area was carried out by Fukazawa t al. (1961a.b). SameJima _t _l. (1969) and kakayama and Sato (1971a.b) using the individual isolated myofibrillar proteins in model gelation systems. It was generally concluded that myosin and actomyosin were the proteins that produced.the greatest gel strengths and. therefore, were the most important in binding. In addition they found that in most 03.898 actomyosin was a more effective binding agent than myosin. In contrast to these results. HacFarlane g; _l; (1977). Ford 9; al_. (1978) and Turner gt a_l_. (1979) found that myosin was superior to actomyosin in binding meat pieces together in both.a model binding system and in a reformed beef product. Although this difference seemed hard to reconcile. an explanation is found in the work of Yasui gt _1. (1960). Using a model gelation system they showed that the addition 0f myosin t0 actomyosin produced a gel that was much stronger than either myosin OP actomyosin when 14 used separately. Hence. the results obtained by HacFarlane _; _g. (1977) is explained by the interaction of the added myosin with the actomyosin present in the surface of the meat to form a strong binding matrix and.the inability of actomyosin to do 811111181417. Gelation 21 Proteins A discussion of gelation necessitates defining some commonly used terms associated with.this phenomenon namely: denaturation. aggregation. coagulation and gelation. Denaturation has been defined as: (1) a process (or sequence of processes) in which.the spatial arrangement of the polypeptide chains within the molecule is changed from that typical of the native protein to a more disordered arrangement (Kauzmann. 1959). (a) as a process in which.a protein or polypeptide is transformed from an ordered to a disordered state without rupture of covalents bonds (Scheraga. 1963). or (3) any process. except chemical modification. not involving rupture of peptide bonds Which causes a change in three-dimensional structure of a protein from.its native in-vivo form.(Haschemeyer and Haschemeyer. 1973). These definitions suggest that denaturation is not an 'all-or-nothing" phenomenon but rather a continuous process with.various areas of the protein molecule changing at different rates (Paul and Palmer. 1972). 11 Dr tc 15 Tanford (1988) qualified Kauzmann's definition by requiring that there be no alteration in the protein's primary structure. Denaturation can. therefore. be restricted to the continuous process of native protein structural changes involving the secondary. tertiary. or quaternary structure in which.alterations of hydrogen bonding. hydrophobic interactions. and ionic linkages occur during the transition to the denatured state (Anglemier and Montgomery. 1976). Bond energies that contribute to native structure and maintenance Of a protein's conformation were published by Acton and DICK (1984). These bonds can 8180 be Viewed as important in protein that 18 denatured. Once a new structure 18 formed. the same types 0f bonding can contribute to the stability 0f the new structure (Acton and DICK. 1954). Denaturation involves protein-solvent interactions and leads to changes in physical properties. such as loss of solubility of the protein. Sometimes unfolding of the protein structure is considered part of denaturation (Gossett gt 9;. 1984). Denaturation is usually irreversible if the methods are drastic. the molecular weight of the protein is large and aggregation occurs to prevent a return to the native state. 16 Aggregation is a general term which.has been used to describe many types of protein-protein interactions. with formation of complexes of higher molecular weights (Hermansson. 1979). Aggregation is usually governed by a balance between attractive and repulsive forces. Attractive forces can involve hydrogen bonds, covalent bonds such as disulfide linkages. and hydrophobic association. whereas. repulsive forces can involve coloumbic forces which.are affected by the net charge of the protein molecule or the ionic strength of the solution (Egelandsdal. 1980). Aggregation causes the meat protein matrix to shrink which limits the amount of water the matrix can bind and reduces the strength of the forces immobilizing the water. The end result of these changes is a decrease in water holding capacity (Hermansson. 1988). Coagulation is the random.protein-protein interaction of denatured protein molecules. in which.polymer-polymer interaction are favored over polymer-solvent reactions (Schmidt gt 2;. 1981). The coagulum.is often turbid. and the formation of the coagulum is usually thermally irreversible (Shimada and.Hatsushita. 1981). A coagulumLmay settle out of solution because randomness does not lead to an orderly structural assembly 0f the final aggregate. 17 Gelation is the orderly interaction of proteins. which may or may not be denatured and which leads to formation of a three dimensional well-ordered structural matrix (Hermansson. 1978). Polymer-polymer and polymer-solvent interactions. as well as attractive and repulsive forces are balanced such that a well-ordered matrix can be formed (Schmidt 2; al. 1981). Since denaturation is involved in this definition of gelation it is evident that native protein structure is altered when the gelled protein matrix 18 formed. Mechanism 2; Protein Gelation The ClflSSlC explanation 0f protein gelation 18 the two-step process proposed by Ferry (1948): Native protein --> denatured protein --> aggregated protein The first step is considered a denaturation process and the second step an aggregation process. Comparison of the rate of the denaturation step vs that of the aggregation step helps determine gel characteristics. For example. Ferry (1948) suggested that for a given rate of denaturation the rate of aggregation will be slow if the attractive forces betweenfthe denatured proteins chains are small. The resulting gel will be a finer network of proteins chains. will be less opaque and will ethibit less syneresis than one with a faster rate Of aggregation. A coarser network Of 18 protein chains yields an opaque gel with large interstices capable of holding solvent which is easily expressed from the matrix. Hermansson (1978) elaborated on Ferry's mechanism stating that contrary to coagulation. where aggregation of the protein molecules is random. gelation involves the formation of a continuous network exhibiting a certain degree of order. Furthermore. when aggregation is suppressed prior to denaturation the resulting network can be expected to eXhibit a higher degree of elasticity than if random aggregation precedes denaturation. The slower the second step relative to the first. the more orderly the denatured chains will tend to orient themselves and therefore a more finer gel network will be produced. Ferry (1948) estimated that the number connecting points between protein molecules was very small. and that for gelation as few as 5—6 loci per chain were sufficient to form a rigid network. The mechanism of gel formation differs among proteins. predominantly in the type of interactions which.stabilize the gel (Schmidt gt 3;. 1981). The type and strength of these connections influence the response of the gel to stresses such as mechanical agitation or temperature change (Paul. 1972). Anglemier and.Hontgomery (1978) stated that long proteinaceous fibers form a three-dimensional 19 network primarily through the establishment of interprotein hydrogen bonds. and probably not through salt bridges which would be highly solvated in aqueous gels. Schmidt 5; _l. (1981) suggested that if aggregation occurs simultaneously with denaturation an opaque. less-elastic gel results. During the storage of a gel syneresis or loss of fluid may occur as a result of the formation of additional interprotein bonds which.decrease the number of loci available for binding water and reduce the amount Of intermolecular space available 1.0 imobilize water through capillary forces. Since the kinetics of the denaturation step relative to the aggregation step appear to be important in determining the type of gel produced. some kinetic terms that aid in describing the gelation process will be reviewed. The first is the reaction rate constant k (min’l). which.is obtained from.the first order relationship (Lund. 1975): _. .39... = kC (1) dt mere C 18 concentration aha ‘dC/dt 18 the rate at which concentration decreases. Rearranging Equation (1) we obtain: dC C = kdt (a) 20 Integrating between limits C1 at time = o and C at time t Equation 2 gives: LnC = Ln C, _ kt (3) A plot of Ln C vs t gives a line of slope -k. The rate constant is usually temperature dependent and can best be described by the Arrhenius equation: k = S e-Eo/RT (4) where S 8 frequency factor (min ")3 Ea 8 activation energy (cal/mole); R a gas constant (1.987 cal/mole °K); T - absolute temperature (°K). A plot of Ln k vs i/T gives a straight line of slope -Ea/R. Hechanism g; Gelation g; myofibrillar Proteins For muscle proteins during processing. thermal energy is the single most important driving force in protein transition from the native state to the denatured state. For myosin and the actomyosin complex it is a continuous process of native protein structural changes involving secondary. tertiary and/or quaternary structure. Hydrogen bonding. hydrophobic interactions and electrostatic linkages are altered during transition.to the denatured state (Anglemier and Montgomery. 1976). While electrostatic and hydrogen 21 bondings become weaker upon heating the potential for hydrophobic bonding increases and with conformational changes there 18 greater tendency for more interchain hydrophobic interaction to occur (Acton and Dick. 1984). Heat induced formation of a three-dimensional protein matrix by myosin and actomyosin. termed gelation. can be represented by two stages of reactions. Each.stage involves distinct segments of the myosin molecules. More critically. the stages occur in separate temperature regions during heating. One stage of aggregation occurs between 30 and 50 °C and the second stage occurs at temperatures > 50 oC. Thus. in the protein— protein interactions of myosin. each stage by temperature region can be represented independently using Perry’s two-step sequence of reactions. It is obvious that in applying this to processed meats. heating to a final internal temperature of between 65 and 71 °C involves both stages as both temperature regions are traversed (Acton and DICK. 1984). The first stage involves aggregation Of the globular head regions Of the molecule. It 18 an irreversible reaction assuming heating will be continuous with continuous temperature elevation On the system. Through studies with the 3-1 fraction. m (heavy meromyosin) segment and myosin. the aggregation 18 thought ‘10 be dependent On oxidation Of -SH groups which are predominantly found in the globular 22 head region (SameJima gt 3;. 1981; Ishioroshi gt 3;. 1979). While -SH group reduction (moles -SH/mole segment) progressively increases from 20 to 70 0C. considerable reduction of -SH content occurs in the early temperature range of 20 to 50 °C for myosin or segments containing a globular head position (Acton and Dick. 1984). Studies from Ishioroshi g; 3;. (1980) support the role of sulfhydryl group involvement in head-to-head aggregation as one factor of the protein interactions. For sulfhydryl group oxidation to occur it is necessary for head-to-head aggregation to have been preceded by a rapid conformational change in the head region. particularly if covalent disulfide bonds are formed. Foegeding gt 3;. (1983) reported that myosin gels heated to 70 °C were stabilized by non-covalent and disulfide bonds. In addition. they reported that gels heated to 50 °C were less difficult to solubilize (by guanidine hydrochloride and urea) than gels formed at 70 °C. Liu 3; al. (1982) concluded on the basis of ease of solubilization (by ex SDS) of actomyosin gels heated to 48 °C. that hydrophobic interactions were the predominant force in actomyosin aggregation below so °C. Solubilization of myosin gels heated to 50 °C by guanidine hydrochloride 23 and urea. as reported by Foegeding gt 3;. (1983) also implies that hydrophobic and.hydrogen bonding are more important than sulfhydryl group reduction. The two-step sequence Of conformational change in the head region and head-to-head aggregation satisfies Ferry’s mechanism in the first stage between 30 and 50 0C (Acton and Dick. 1984). The second stage is associated with structural change of the helical rod segment of myosin which culminates in network formation through cross linking of these segments. While the globular head interaction predominates in the first stage there is also apparent early disruption of the o-helix at the hinge region in moving from.the coiled-coil (o-helix) to a random coil type structure in the same lower temperature region. Further helical disruption of the tail portions requires a higher energy input. thus these helical alterations predominate in the second stage at temperatures > 50 °C. The coiled-coil to random coil conformational change in the tail region is extremely important to aggregation occurring in the second stage of events. The LHH (light Ineromyosin) (Ishioroshi et 1. 1982) and.the myosin rod 24 (SameJima _3 _l. 1981) ultraviolet absorption difference spectra at 285 nm. where the aromatic side chains of the protein absorb. confirmed that absorption increases as both segments are heated from 20 to 85 °C. In addition several workers have reported an increase in binding and enhancement of fluorescent intensity for actomyosin (Niwa. 1975) and myosin (Lim and Botts. 1987) upon heating in the presence of ANS (8-anilino-1-naphtalene sulfonate). ANS is a fluorescence probe capable of binding with.hydrophobic regions of proteins when.the conformational structure allows reaction with.nonpolar residues. The binding of ANS is initiated at temperatures beginning in the 35-45 °C range. The fluorescent intensity increases with.further temperature increase. The exposure of hydrophobic residues facilitates hydrophobic interactions. and thus. increases the potential for tail-to-tail cross-linking in establishing the gel framework. (Acton and D1CK. 1954). In the gelation type protein-protein interaction. it is evident that there is a second reaction to aggregation driven by thermal energy input where the product of the first step becomes the reactor for aggregation in the second step. This sequence of reactions or steps in the formation Of three dimensional protein matrices has been proposed by .Acton t l. (1983). 25 Effect gt Temperature gg _gt Strength Yasui gt gt: (1980) investigated the effect of temperature on rigidity of rabbit myosin and actomyosin gels. They found that the gel strength started to increase at 40 °C and reached a maximum at 60 °C. A similar result was obtained by Grabowska and Sikorski (1976) using fish myofibrils. with the difference being that the increase in gel strength started at 30 °C and continued up to a temperature of 80 °C. These results were confirmed in principle by the work of Quinn gt gt. (1980) who showed. using differential scanning calorimetry. that denaturation of meat (beef) proteins begins at about 50 °C and continues with increasing temperature up to 90 °C. This work and that of Wright _t g (1977) shows that the temperature range of denaturation of the different protein components is a characteristic of the species of animal from.which.the protein came. the pH and the ionic strength. This information explains the varying results obtained by different workers in this area. as each group used different combinations Of animal species. PH and ionic strength. Acton (1972) investigated the effect of temperature of cooking on the binding ability of poultry loaves. The results obtained on binding ability were basically the same as those obtained by workers measuring gel strength of isolated proteins. In essence. the binding strength.started 26 t0 increase at 40 oC and reached a maximum at 50 °C. after which it decreased slightly with temperature up to 100 °C. The effect of temperature on the binding ability of crude myosin (beef) was investigated by Siegel and Schmidt (1979). Their results showed that binding strength started to increase at 55 °C. then increased linearly with temperature to 80 °C but did not show the same decrease in binding ability after 80 °C as reported by Acton (1972). The difference in response of binding ability to temperature obtained by the two different groups of workers may have an explanation similar to that given for the variation in gels of purified proteins. which was the difference in species of animal. PH and ionic strength used by the two groups. From all the gelation and meat binding studies. the temperature region above 50 00 appears most critical. Gels do not reach appreciable strength until the myosin tail portion has undergone helix-coil transformation and subsequent cross-linking. The myosin head region is important since. from ultrastructure studies. it appears to form the initial super-Junctions upon which.the super-thick filament network interlinks (Siegel and.Schmidt. 1979: SameJima _t _t: 1981). Similar studies of gelation of natural actomyosin (Deng gt‘gt. 1978; Acton gt gt. 1981; Liu t l. 1982; Ziegler and Acton. 1984) have shown that the ultrastructure of actomyosin gels is one of thinner 27 filamentous strands with larger pore size distribution and a different cross-linked appearance when compared to myosin gels (Yasui gt gt. 1982). These ultrastructure studies showing morphological differences between myosin and actomyosin gels imply that in processed meats. differences in textural attributes between prerigor and postrigor raw materials may emerge in the finished product (Asghar t l. 1985). From.the research that has been done on the effect of temperature on gel-strength and binding ability of meat proteins. it can be concluded that there is an interaction between the temperature of heating and the presence and concentration of different salts. The exact interaction has not been clearly elucidated. but the implications is that the temperature at which maximum binding occurs is dependent on the presence of specific salts and.hence the ionic strength and pH (Quinn gt gt. 1980). Theoretical gggtg gt tgg Mathematical ggggt To evaluate the effects of heat treatment on the thermal gelation of myofibrillar beef proteins a universal method is needed by which.all heating processes can be quantified and compared to a common reference point. This method would facilitate comparison between controlled 86 constant temperature processes and variable temperature-time treatments and incorporate effects of variable heating rates. variable protein concentration and added gums. A mathematical model was developed by Morgan (1987) and is based on fundamentals of protein kinetics and polymer rheology. The model combines theories of how temperature and protein concentration at constant shear rate affect viscosity of non-Newtonian fluids and protein polymerization (gelation) reaction kinetics and assumes that apparent viscosity is a relative measure of gel strength. Concentration Effects A logarithmic relationship of moisture to dough viscosity was proposed by Harper gt gt. (1971). Later the same group used a semiempirical logarithmic mixing rule to describe the effect of moisture content on viscosity of corn flour dough.and proposed a formula that predicts concentration effects on viscosity of suspensions or solutions. NC = NCO e 8 (concentration) (5) *where C is concentration of total dry matter. 8 is the parameter which quantifies relative effects of concentration. NC 18 the viscosity index at a particular 29 concentration and Nco is the viscosity of the solvent. This model assumes that C remains constant and that the trapped water has a lubricant effect. Rheological and Kinetics Background A pseudo first-order reaction is used as starting point to model the heat activated chemical changes responsible for thermal gelation of myofibrillar beef proteins. The reaction model is based.on the assumption that rheological and kinetic theory presently used in studying plastic polymers might be used as starting point for modelling gelation of protein solutions. Considerable theory has been developed for predicting polymerization phenomena of plastics and similar materials. Mathematical relationships have been developed using molecular and physical entanglement theories to predict rheological properties of polymers (Ferry. 1970). Sha and Darby (1976) used molecular weight data to successfully predict apparent viscosity of polyethylene melts which.had weight-average molecular weights ranging from 57.700 to 139.000 daltons. Several problems are encountered.when attempting to draw analogies between plastic polymers and protein reactions. Polymers generally undergo various reversible melting and irreversible polymerization reactions during thermoplastic extrusion. However. proteins undergo irreversible denaturation with network entanglement and 30 possible cross-bonding. Generally. first or second order reactions are assumed with reactive plastic polymer and monomer species. whereas the thermal gelation of myofibrillar beef proteins involves several higher order reactions. However. perhaps the end effect of this heat-mediated gelation of myofibrillar proteins could be described via a first order reaction analogy (Blum. 1960; Penny. 1967; Deng gt gt. 1976; Ziegler and Acton. 1984). and then a simple reaction could be used to approximate the average overall viscosity effect due to thermal denaturation of the major myofibrillar proteins. When a solution of myofibrillar beef proteins is heated. the proteins undergo irreversible denaturation with network entanglement and cross-linking that involve several higher order reactions which occur simultaneously or in cascade. These denaturation reactions will affect their size. shape and molecular weight. Since apparent viscosity is related to all of them. it seems logical to assume that molecular changes caused by the gelation reaction will significantly affect the material’s apparent V186081tY. The pseudo first-order kinetic model used in this study to model temperature-time history effects of myofibrillar protein denaturation (gelation) On apparent viscosity 31 assumes that concentration of the reactive polymer species will remain constant and predicts disappearance of the monomer species. The pseudo first-order reaction is described by the formula: Mc(t) .-_ Mge-kt (6) where Hc is concentration of the monomer at time t. N1 is the initial monomer concentration. and k is the first order reaction rate constant. The molecular weight of a polymer can be approximated by: MWp = MWm DP (7) where HWp is the polymer molecular weight. HWm is the monomer molecular weight. and DP the degree of polymerization (Williams. 1971). Williams. (1971) also approximated for pseudo first order polymerization the number—average degree of polymerization (DP) as _ Mi — Mc ) DP - ( PC (3) where PC 18 the reactive polymer species concentration and Hi and Me as describe in Equation 6. 32 Ferry (1970) reported a power law relationship for correlating the zero shear rate limiting Newtonian viscosity (fl) Of polymers with their mblecular weight: a 77 = k2(MWP) (9) where k3 is a viscosity coefficient and a a dimensionless constant. Theoretically. a is derived to be 1.0 for low molecular weight polymers and 3.5 for high molecular weight polymers. Sha and Derby (1976) reported that observed values of c found in the literature range from 3.4 to 8.0 for high molecular weight polymers. Therefore. it was assumed that effects of changing molecular weight during protein polymerization is described (at constant shear rate) by: a. TIM») = k1(MWP) ( 10) where k2 is assumed to be dependent on t and Hc according to Equation 6 with a material-constant factor included in the expression. Equations 6. 7 and 8 were combined.with Equation 10 yielding n. as a function of reaction time (t). for constant temperature (T). 33 um - u.( “if-"£3- )“(1-6-“ a (11) Equation 11 describes the increase in protein gel viscosity due to heat-induced denaturation and assumes that total dry matter remains constat and shear rate is very be low (near zero). This increase is a function of time for all temperatures (T) greater than the threshold temperature (Ta) . The pseudo first-order reaction used in developing Equation 11 assumes that temperature is constant and greater than the reaction threshold temperature. The coefficient k1 is defined as the polymerization rate constant. Kinetic theory implies that k1 is related to temperature by: -Ed/RT k1 = kte (12) Where k1 is a specific reaction constant and Ed is the activation energy of protein denaturation. According to Eyring and Stearn (1939) k1 is related to absolute temperature by: 'T kt ko (13) h k... where kt is a transmission coefficient. kb is Boltzman's constant and.h is Plank‘s constant. 34 Application of Equation 12 and 13 to Equation 11 requires that temperature remain constant with time. However. temperature in most experimental conditions. as well as in almost all commercial processes. will increase from its initial temperature to process temperature in a variable time. Therefore. each process will result in a distinctive and variable temperature-time history within meat products. To meet this need an integral temperature-time history (TTH) developed by Horgan _t gt. (1979) was incorporated into Equation 11. This function is defined as: 00 TTH = f T(t) e-AEO/mdt W“ 0 where Ea : activation energy. R = universal gas constant and T(t) is the temperature-time profile above some minimum threshold temperature (Td). Morgan (1979) developed the TTH function based upon work by Eyring and Stearn (1939). TTH is defined as zero for all T(t) below the Td. Its assumed that the gelation reaction is not initiated until the temperature is at or exceeds Td and its effect is a multiplicative increase in Viscosity due to the myofibrillar protein thermal activated gelation. 35 Assuming constant moisture. Equations 11 and 14 could be combined to give an expression for the incremental change in apparent viscosity due to the thermal gelation of myofibrillar beef proteins. 77(T—t) = 770(1.+A(1-_-€'°m)“) (15) where n represents the viscosity of the myofibrillar protein in solution before heating. ”A" is a parameter which relates the ratio of maximumlheat-induced gel viscosity to initial viscosity. "a" is related to the reaction rate constant for protein denaturation and cross-linking. o is a function.of the shear rate and a relative measure of molecular entanglement during shear and TTH is defined by Equation 14. Equation 15 is the basic model utilized in this study for predicting the combined effects of temperature. protein concentration. time-temperature history and selected hydrocolloids gums (carrageenan. guar. locust bean and xanthan) on apparent viscosity of myofibrillar beef proteins solutions. where protein gelation was heat induced. Similar models have been used to model TTH effects of protein denaturation on apparent viscosity index (Horgan gt 1. 1988: Harper t l. 1978; Smith.gt gt. 1988). Harper gt 1. (1978) successfully applied this approach to heat setting Of bovine plasma proteins suspensions. whereas Smith e l. (1988) found good correlation when they appl1ed 36 such a simple reaction model to approximate the gel strength in the thermal gelation of chicken myofibrillar protein suspensions and drew the analogy between kinetic losses of protein tertiary structure and pseudo first-order polymerization. This analogy assumes that increases in viscosity due to protein gelation is analogous to the viscosity increase brought about by increased polymer molecular weight during a classical polymerization process. This evidence supported the idea that such an approach was adequate for modelling the thermally-activated gelation of myofibrillar beef proteins. Characteristics gt szrocolloids Macromolecular hydrocolloids or gums. as some are more commonly known. are used by the food industry as texture modifying agents in many different types of products. The term gum.refers to a wide variety of compounds including polysaccharides of plant and microbial origin. animal proteins such as gelatin and some chemical derivatives of cellulose (Andres. 1975). Many gums have the ability to form gels at low concentration. physically binding water into a three dimensional structure. The water held by these gels eXhibits physical properties similar to those of free or bulk water and is not easily removed from.the structure when physically stressed. 37 Hydrocolloids have several properties that are valuable to meat technologists and are used for several different functions. such as stabilizers and structure forming (gelling) agents. These functional properties are related in part to the ability to imbibe and retain large amounts of water. to interact with proteins and to bind fat (Wallingford and Labuza. 1983). Some of the gums that have been reported in meat products are: xanthan. guar. locust bean and carrageenan. Guar gum is a very effective water binder in comminuted meat products. canned meats and pet foods. The anionic xanthan gum and locust bean gum have been shown to prevent fat separation in canned meat. whereas. carrageenan stabilizes the texture of frankfurter emulsions against acid deterioration (Pedersen. 1960; Abd El-Baki gt gt. 1981; Fox. 1983). Xanthan gum is a high molecular weight polysaccharide gum produced by a pure culture fermentation of a carbohydrate with.Xanthomonas cggpestris. and is purified by recovery with isopropyl alcohol. dried and milled. The linear portion of this colloid is composed of repeating units of D-glucose and is chemically identical to cellulose. The side chains which.accounts for xanthan's water solubility are made up of D-mannose and D-glucuronic acid subunits and also contain approximately 3% by weight 36 pyruvate (McNeely and Kang. 1973). It is a white to cream colored powder that is readily soluble in hot and cold water and is prepared as a mixture of potassium and sodium salts. Because of its chemical structure it is able to form highly viscous and stable solutions at low concentrations at room temperature. These solutions eXhibit pseudoplastic characteristics as a result of the rigid cellulosic backbone that is stabilized by the side chains (Morris _t _t. 1977). The principal properties exhibited by solutions of xanthan gum which are important to the meat industry are: a high degree of pseudoplasticity. a high tolerance to salts. very high stability towards extremes of temperature. pH. ionic strength and shearing force. an ability to suspend particulate matter. the synergy with galactomannan gums and the resistance to enzymatic degradation. Guar gum is a seed gum.composed of linear chains of D-mannose with numerous short side units composed of D-galactose. It has a molecular weight of approximately 220.000 daltons and forms colloidal dispersions in cold water (Goldstein and Alter. 1973). Guar gum is not highly branched. with.the side chains consisting of single galactose subunits. Therefore. guar dispersions. which.have fairly high viscosities in comparison to more highly branched molecules of equal molecular weights. should absorb less water but still give a relatively high.water holding capacity. 39 Locust bean gum consists of a linear chain of D-mannose as does guar gum. However. it differs in the level of substitution of D-galactose on the side chains. with one substitution every fourth or fifth molecule of mannose compared to every second molecule for guar gum (R01. 1973). It has a molecular weight of the same order as guar gum. approximately 310.000. Locust bean gumlhas a fairly low water holding capacity (WHC) at 515g water per 100g dry gum solids. The dispersability of locust bean gum at room temperature appears to be the key to this gum’s low WHC. Crystalline regions within the gum's structure fail to solubilize at room temperature. only breaking up as the solution is heated. Cold water dispersions of locust bean gum have a significantly lower viscosity (about ten times) than hot water dispersions (R01. 1973; Andres. 1975). Carrageenan is not a well-defined substance. but rather a designation (a family name) for a group of salts of sulphated galactans. They have been defined as that group of galactan polysaccharides extracted from.red algae (Rhodophyceae) of the Gigartineceae. Solieracea. Hypneacae and Phyllophoracea families. and.that have an ester content of 202 or more and are alternately a 1-3. B 1-4 glycosidically linked. Various types or fractions of carrageenan are defined according to idealized structures and designated by greek letters lambda. kappa. iota. etc. 40 The different carrageenan fractions (kappa. iota. lambda. etc.) occur in varying ratios in various red seaweeds. By selection of seaweeds it is. therefore. possible to obtain carrageenans which are predominantly of one type. Blends with controlled intermediate properties are produced by blending extracts or seaweeds before the extraction Step. Galactose is the most common repeating monomer. The solubility of carrageenan depends on the hydrophilic sulfate half-ester groups present and the galactopyranosyl unit. and therefore. a range of solubility is found for the various types of carrageenans (Stoloff. 1973). Carrageenan is reported to have a molecular weight of about 300,000 daltons (Marine Colloids. Inc.) which.1s much lower than that of xanthan gum. Carrageenans are capable of forming viscous solutions at low concentrations in cold water with the viscosity dependent on temperature. pH. concentration. type of carrageenan molecules and solutes present. METHODS AND MATERIALS Experimental Design This study was conducted in two parts. the first of which.was a model system experiment designed as the . experimental base for developing a mathematical model for the thermal gelation of myofibrillar beef proteins. The second part of this study was designed to test if the model developed in part I could be applied to the thermal gelation of myofibrillar beef proteins combined.with.selected hydrocol lOidS. Experiment t This experiment was designed to be the experimental base for testing a proposed.mathematical model developed by Morgan _t gt. (1987) and to determine if it could be applied to,a model meat system of myofibrillar beef proteins. The mode 1 proposed was: 77(T-t) = no(1+A(1-e‘°"“)“) where individual model components were described previously. This model describes the gelation of myofibrillar beef 41 42 proteins (measured as the back-extrusion apparent viscosity) as a function of the time-temperature history of the process and the protein concentration of the samples. The experiment was carried out as described below. gggt Sample Preparation. Beef was excised from the bottom round (biceps femoris) of six young bulls slaughtered at the meat laboratory facility (MSU) and allowed to age three days. The exterior and seam fatty tissue and the epimysial and perimysial connective tissue deposits were physically removed prior to grinding the muscles. After passing the tissue twice through a chilled grinder with plate orifices of 4.8 mm diameter. the muscle mince was divided into lots of approximately 600 g. vacuum packaged and stored at -30 °C. until required for the experiment. Isolation gt Mzofibrillar Proteins. Myofibrillar beef proteins were extracted in a 2 °C cold room.following a procedure describe by Eisele and Brekke (1981) and Smith _t _t. (1988) with some modifications. The frozen ground meat samples were allowed to thaw overnight in a 2 °C cold room. A meat sample (about 600 g) was then blended for 30 sec in a Waring blender at maximum speed with 4 volumes (2400 m1) of 0.1H sodium dhloride and 0.05M sodium phosphate buffer. pH = 7.1. The suspension was stirred for 60 min at 1200 rpm using an electronically speed-control led stirrer (Heller GT-Zl) equipped with a LH Jiffy Mixer stirrer shaft 43 (Thomas Scientific Apparatus. cat. 8634-820) to avoid air incorporation into the protein suspension. The solution was transferred to 250 ml centrifuge plastic bottles and centrifuged at 9000 x G for 15 min at 0 °C in an automatic refrigerated centrifuge (Sorval RC-2B). Any connective tissue which accumulated on the propeller was discarded. The supernatant containing fat and sarcoplasmic protein was discarded and the pellet resuspended in 2400 ml of fresh buffer. The extraction procedure of stirring. centrifuging. and resuspension was repeated 3 times. The final pellet was analyzed for nitrogen content and adjusted to a selected protein concentration (1. 2. 3. 4. 5 or 6%) and to pH 6.5. Buffer salts concentration in the water phase were 0.5z (w/w) sodium.chloride and 0.5% (w/w) sodium pho sphate . gggt Treatment. Protein suspensions were transferred to 16 x 100 mm disposable culture tubes (approximately 10 g per tube) and thermally processed in a water bath (model FG-103. Eberbach. Corp.. Ann Arbor. MI.) at six different temperatures (54. 64. 70. 75. 80. and 85 00). Samples were taken at variable intervals ranging from 30 to 13.000 sec. Heat-treated protein solutions were immediately transferred to an ice-water bath. permitted to cool for 30 munutes and stored overnight at 2 °C. 44 During the thermal process the temperature at center of each tube was monitored with a thermocouple thermometer (model 450-TT. Omega Engineering. Inc. Stamford.CT.) inserted in the center of the tube. Temperature was recorded every 30 sec until the center of the tube reached the temperature of water bath. ggt Strength. Before measuring the gel strength. cooked protein samples were transferred to a water bath.at 20 °C and allowed to equilibrate for 2 h. Gel strength was evaluated as the back extrusion apparent viscosity using an Instron Universal Testing Machine (Model 4202. Canton. OH) equipped with a 50 N load cell and coupled with a microcomputer (Hewlett Packard 86B). The computer ran a program specifically developed for this experiment (program Rodrigo. appendix A). This program established Instron operating variables: speed 20 mm/min. travel distance 30 mm. load calibration cell 50 N. Distance (mm) and Force (N) were read by the program every 300 milliseconds as a 7.33 mm.diameter plunger (flat tip) penetrated the gel at constant speed. Distance-force data were used by the computer to calculate the back-extrusion apparent viscosity and.the apparent elasticity using the procedure described by Hickson gt gt. (1982). The peak plunger force was calculated as the equivalent force of a linear force deformation triangle which resulted 45 in an area under the force deformation curve equivalent to the observed curve. The deformation base of the triangle was the same as that of the observed curve. The equation for computing equivalent peak force (Fp) was: 2 AREA (16) F = p Lp area under the force deformation curVe; plunger travel distance.. where area Lp The viscosity index (n) was computed using Equation 17 (Hickson. gt gt. 1982). l 77 = 5.7)('3)(1-K2)Ln(%)(1+fi <17) where Vp = velocity of plunger (mm/min); K a ratio of plunger diameter to tube diameter; a = (1-K=)/(1+K=); Lp = plunger travel distance (mm); Fp = plunger force as describe before (N). Evaluation gt tgg Thermal Process. The time-temperature history (TTH) of the gels was calculated with.a macrocomputer (Hewlett Packard 86B) using a program specifically developed for this purpose (program Mariana. Appendix C). Basically the program used the experimental time-temperature data collected during the thermal gelation Of the myofibrillar proteins and calculated the Fourier 46 number (Fo) and.the dimensionless temperature ratio 9 using Equations 18 and 19. kt (18) F0: Cp rzp _ (TL—Too) 9 _ (Tc—Too) (19) where t = time in seconds; r = internal radius of test tube; Cp = caloric capacity calculated as 1.675 + 0.025 Moisture; p : density as weight/volume (1069 Kg/m3); - T1 = initial temperature of sample (normally 20 00); Tc = temperature at the center of test tube (°C); T0° = temperature of the water bath (°C); k : thermal resistant constant from Equation 20. Thermal resistance values were not found in the literature for this type of gel. Therefore a formula which gave "k" as a function of temperature was developed. For this purpose. data published for veal. lean beef. and pure water were used (Heldman. 1985). Because the value of ”k" changed with moisture and temperature. an average "k” for 902 moisture was calculated (i.e. the moisture expected in this gel). Then using values for 40 and 80 °C. the following linear relationship was created: k = 0.274 + 1.4146 E(-—4) T (20) 47 where T: temperature in °C. With the above data the Biot number was calculated for each one of the experimental time-temperature points using an approximation to the general equation. This approximation was found to be good for a range of F0 values greater than 0.15. The approximation was calculated using a simplification of the general formula for transient heat transfer in an infinite cylinder (Equation 21). 2 . “lint-o f a = 2 Momfie (w 2 Bi Idem) (In-sf ) ] where A .. = e = as defined in Equation 19: Jo : Bessel function; u = root 1 of Bessel function; 'r : radius of point for temperature 1; R : radius of tube; F0 2 as defined in Equation 18; Bi : Biot number. For the special case Of the center Of the tube (r/R - i) and considering only the first root Of Ii Equation 21 could be written as: 2F (9 == AuJo);L:}€3 or 46 Ln(6) = Ln(A1)+Ln(Jo§p1})—p.fFo (23) Using values reported in the literature (Luikov. 1968). it was found that for F0 > 0.15 Biot number was related to u and A. (R3 = 0.99 and 0.989 respectively) by the equations: 435842959 Ln(B.) = 0.08359... (24) and - 8£W8 Ln(Bi) = 0.060637 A: (25) Combining Equations 34 and 25. 1t 18 found that for this special case A1 is related tO u by: Ln(A1) = 0.03974+O.5395 Ln(,u.) (26) When n: 1. the argument of the Bessel function approximates (0) and then Jotu): 1 and.therefore Ln(Jo[u)) - 0. When this value and Equation 26 are substituted in Equation 23. it gives: (27) Ln(6)*uaFo-0.03974-0.5395 Ln(u)=o 49 A computer subroutine (program Mariana) using the secant method was utilized to find n values that satisfied Equation 27 and then utilized these values to calculate a BiOt number for each experimental time-temperature point as: 4seeumo9 . 359 Bi':= 80 08 l1: (28) Followed by the average Biot for a user-selected range. After defining the Bi number from experimental data. the time-temperature profile was calculated based on a transient heat transfer model for infinite cylinders reported by Parker gt gt. (1970). This model predicts temperature-time data for ten different radial positions within a given test-tube cross-section based on the initial. center and bath.temperatures for each treatment. The cross-section was divided into ten concentric rings defined by the preselected radial position. The computer program utilized the general formula for an infinite cylinder again (Equation 21). but in this case r/R was a variable and u was calculated to its sixth.root. Then the general equation could be represented as: 5 -IJ:Fb 6 = awash-.26 50 where u roots where calculated using Equation 30. ano(;.Ln)-B.Jo(pn) = O (30) The solution of the general equation gave a value of e as function of r/R and time (as Fo). Using the calculated value of 9. temperature Tc for any point r/R at any time (F01) could be calculated by rearranging of Equation 19. as shown in Equation 31. T. = 6(T.—T-)+T. (31) This generated an 11 x 60 time-temperature matrix which was used to calculate the effect of the temperature at each selected r/R point as an A' factor. The A' factor was defined as: -&VRT A' = Te <32) Activation energy: Absolute temperature (°K): Ideal gas constant. where Ea T R The TTH value was the accumulative effect of the average A' of two points times the time interval between these two points (30 sec) as represented by Equation 33. 51 TTH = § (33) These procedures calculated the TTH for each ring which.then were averaged over rings to obtain a final TTH average. Determination gt Activation Energy. The activation energy of this pseudo first order reaction was calculated in two steps. The first step estimated a range of values for the activation energy. To do that. high. medium and low values of apparent viscosity were selected in such a way that values for time of cooking at different temperatures were obtained for the same apparent viscosity (protein concentration = 4.092). A plot of natural logarithm of time versus the inverse of the absolute temperature of cooking yielded a slope equal to -Ea/R where R = constant of ideal gases (1.987 cal/°K-mol). These plots gave a range of values for activation energy between 16.000 and 42.000 cal/mol. The second step calculated the final Ea value by an optimizing computer routine. TTH values for Ea = 16.000 and 42.000 cal/mol were plotted versus apparent viscosity and the linear range selected. Selected values for the linear region (all temperatures) were utilized as starting points. The computer routine basically did the following: upon an 52 input of Ea value. calculated TTH values for each temperature. plotted them versus n and calculated the regression line. Then. Ea was adjusted and TTH values recalculated until a maximum regression coefficient for the regression line was obtained. A microcomputer (Zenith 148) with the computer package Framework II (version 1.0) linked to the graph-statistical package Plotit (version 1.1) were used for these calculations. A first estimated value for the material constants A and a were calculated using the computer program.Mariana. The final values of these constants were calculated using a non-linear regression analysis (Marquardt. 1963). These calculations were performed by a microcomputer (Zenith 148) with the computer package Framework II and the graph statistical package Plotit. Experiment tt This experiment was designed to test the hypothesis that the mathematical model developed in experiment I could be applied to the thermal gelation of myofibrillar beef proteins combined with selected.hydrocolloids. The gums utilized were Xanthan gum (Miles Laboratories. Inc.). Guar gum (Colony Import & Export Corp.). Locust bean gum.(TIC Gums. Inc.) and Carrageenan gums (Gelcarin XP 4039. FMC Corp. ) . 53 The model meat system used was basically the same as the one used in experiment I. The main differences were that protein concentration was selected to be 2.5% and temperature of cooking was 70 °C. Concentration of gums was 0.5% and they were added mixed with the salts (sodium Chloride and phosphate salts). Chemical and statistical analysis. as well as mathematical calculations. were identical to those in experiment 1, except that the Ea value was assumed tO be equal to that calculated for the myofibrillar system. Methods Qt Analysis Determination gt ggtgp Holding Capacity Water Holding Capacity (WHC) was determined on the ruptured gel/protein suspensions after gel strength.testing. The protein/gel in 16 x 100 ml culture tubes was centrifuged at 2000 x G for 2 h.at 4 C in an automatic refrigerated centrifuge (Sorval RC-3). The weight of the water released was used to calculate the WHC as: W.-W. WHC = w, 100 (34) where Wg 8 weight of the gel; w. 8 weight of the water lost. 54 Buffer Preparation Fresh buffer was prepared the day prior to the experiment. The buffer batch was prepared as follows: 33.2 g of monosodium phosphate monohydrate. 81.9 g of disodium phosphate. 87.6 g of sodium chloride and 2797.3 g of glass bidistilled deionized water were mixed with an magnetic stirrer until all the salts dissolved (approximated 20 min.). The concentrated salt solution was tranferred to a 20 1 plastic bin and 12 1 of water added with agitation. The pH of the solution was checked and found to be between 7.1 and 7.2. The buffer solution was allowed to cool overnight in a cool room at 2 °C before use. Protein Determination Nitrogen was determined by the Micro-Kjeldhal procedure (A.O.A.C.. 1985. 23.009) using a Buchii automated nitrogen analyzer 322/342 equipped with.an Epson HX-20 minicomputer. Protein samples weights were between 0.2 and 0.3 g and the protein content determined as 6.25 times percent nitrogen. Concentrations of chemicals were hydrocloric acid 0.05M. boric acid 4% w/w and sodium hydroxide 30x w/w. Water was glass bidistilled and deionized. Statistical Analysis Linear regression analysis was performed by the least square method using the integrated graph-statistical program 55 Plotit (Eisensmith. 1985). Nonlinear regression analysis was performed w1th.the algorithm for least squares estimation of non-linear parameters developed by Marquard (1963) using the integrated graph-statistical program Plotit (Eisensmith. 1961). Computer Programs Utilized This experiment required intensive use of computer time to expedite the mathematical development of the TTH model for myofibrillar beef proteins. The computer software utilized were of two types: (a) availabe commercial programs and (b) programs especially developed for this experiment. The commercial programas utilized were: Framework II (Ashton Tate. 1985). Plotit (Einsensmith. 1985) and TK!Solver (Software Arts. Inc. 1963). Specifically developed for this experiment were three computer programs. They were named: program Rodrigo. program Mariana and program Delia. These programs were developed in Basic for a Hewlett Packard 86B computer. Program.Rodrigo This program was developed to: (1) calibrate and control the working parameters of the texturometer INSTRON (speed. travel distance. calibration of load cell. calibration of plotter and calibration of load balance). (2) to read every 300 milliseconds the distance-force data 56 generated as a 7.33 mm diameter plunger (flat tip) penetrated the gel at predetermined and constant speed. (3) to calculate the back extrusion apparent viscosity from these data and (4) to save these values for future reference. Figure 1 is a flow diagram of this program. Program Delia This program was developed to read raw data generated and saved by the program Rodrigo. It calculated the back extrusion apparent viscosity and the shear force at the tube wall from.the distance-force data generated and saved during the texture measurement. Figure 2 shows a flow diagram of this program. Program.Mariana This program.was developed mainly to estimate the time temperature history of the process. This program calculated the following individual parameters of the thermal process: the Fourier number. the e value. the Biot number. the time temperature matrix for ten concentric rings. the TTH values for calculated concentric rings and an all-over average TTH. This program was also designed to calculate a first estimate of some of the constants of the basic model (Equation 15) namely: the (a). the d and ’1' values. The thermal process was calculated using the experimental time-temperature data collected during the 57 POWER ON LOAD PROGRAM OUTPUT INSTROM WORKING PARAMETER CLEAR >- INPUT SAMPLE MEMORY DESCRITPTION l READ FROCE AND—T DISTANCE DATA COMPUTE AREA, MAXIMUM FORCE AND APPARENT VISCOSITY SAVE RAw DATA T0 DISK yes Figure 1. Flow diagram of computer program Rodrigo. CLEAR MEMORY 56 POWER ON INPUT i V’ FILENAME READ DATA FROM DISK - 1 [COMPUTE AREA,MAXIMUM FORCE AND APPARENT VISCOSITY . OUTPUT RESULTS TO PRINTE' MORE SAMPLES ? Figure 2. Flow diagram of computer program Delia. 59 thermal treatment of the protein gels. These time temperature values were utilized to calculate the Fourier number and the 9 values. which in turn were utilized to calculate the Biot number. The next step divided the cross section of the test tube (used for cooking the gel sample) into ten concentric rings with equal area and then calculated the time-temperature profile for each ring. The next step calculated the TTH value for each ring. using time intervals of 30 sec. Final TTH values were obtained by averaging individual TTH values for each ring at every 30 sec. The program contains provision for a variable Ea. The second section of the program calculated values of a and A using a regression analysis of selected values of n and their corresponding protein concentration (C). whereas a preliminary value of (a) was obtained by iterating several values of Y' and their corresponding TTH values using Equation 35. Y1 8(1-e'm')“ Y2 8(1'e-flm)‘ (35) Figure 3 shows a flow diagram of the steps followed by this program. 60 Figure 3. Flow diagram of computer program Mariana. 61 POWER ON LOAD PROGRAM INPUT SELECTION CALCULATION OF: (1) THERMAL PROCESS (a) RING TIME-TEMPERATURE ‘P F - PROFILE (3) TTH (4) A' AND C (5) AN ESTIMATED OF Ea (6) AN ESTIMATED OF (a) SELECTED (1 ) no CLEAR MEMORY yes .4 INPUT EXPERIMENTAL TIME-TEMPERATURE DATA COMPUTE F0. 0 AND Bi COMPUTE RINGS RADII AND yes TIME-TEMPERATURE PROFILE SELECT 2 OUTPUT RESULTS TO PRINTER no PROFILE TO DISK i v [SAVE TIME-TEMPERATURE I 62 L_. 1 LI NPUT WANT TO yes CHANGE Ea VALUE no INPUT NEW VALUE OF 53, COMPUTE A'. TTH PER~ RING AND ALL-OVER yes SELECT AVERAGE TTH 3 no 4’33 yes INPUT Y'ATCTIME yes INFINITE AND PROTEIN ~ SELECT CONCENTRATION DATA - no COMPUTE A'. d AND R2 OUTPUT RESULTS TO PRINTER «yes 63 yes INPUT SETS OF TIME- TEMPERATURE DATA COMPUTE AVERAGE Ea OUTPUT RESULTS TO PRINTER MORE no yes CALCULATIONS SELECT no INPUT 3 SET OF VALUES//’ yes 01“ 1" AND TTH -< COMPUTE (a) FOR SELECTED VALUES OF C T OUTPUT RESULTS TO PRINTER MORE CALCULATIONS 7 no RESULTS AND DISCUSSION Determination gt tgg Activation Energy thgg The value of the Activation energy (Ea) of this pseudo-first order reaction was calculated in two steps. The first step estimated a range of values where the Ea value was expected to be. whereas. the second step focused in that range to calculate the final value. This first step was based on kinetic theory. which predicts the reaction rate constant for a given Ea. temperature and time period (Equation 12). For a selected time condition Equation 12 could be written as: -Eo/RT ; k5 = kne (36) If the natural logarithm of both terms is obtained and this is followed by a rearrangement of the terms. then Equation 36 could be written as: Ln(t.) = Ln ._k_>+ E]. _ (37) Equation 37 implies a linear relationship between Ln time (sec) and.the inverse of the temperature (0!) of cooking. The slope of the line is the Ea (cal/mol) divided by the constant Of the ideal gases (R=1.987 cal/mol°x). 64 65 A basic assumption of these experiments was that the heat-induced back-extrusion apparent Viscosity (Y') measured the extent of the thermal induced gelation reaction of the myofibrillar beef proteins. Therefore. by using the time to obtain a predetermined reaction extent (Y': 1.0. 2.0. 2.5. 3.0 and 3.5) at different experimental temperatures it was theoretically possible to calculate the Ea of this reaction. This first step was carried out as follows: A protein solution (4.22) was thermally processed at 54. 64. 70. 80 and 84 °C and the Y' calculated for different time-temperature conditions (Table 1). The back-extrusion apparent viscosity (BEAV) induced by the heat treatment was found to be a function of time for the experimental range and.follow the mathematical model described by Equation 38. Y' = A(1-e"')c (38) where Y'= thermally induced BEAV; . A,B.C = constants related to the basic model (Equation 15); t I time (sec). Experimental Y' and related time values were utilized to obtain the constant (A. B and C) values for each temperature Of cooking. using a non-linear regression algorithm (Marquard. 1963). The calculated constants A. B Table i. Thermally induced back-extrusion apparent viscosity 66 (Y') for the time range of 30 to 350 sec and for five different temperatures. seconds. 30 90 120 150 180 210 240 270 330 360 390 420 450 480 510 540 570 600 630 660 690 720 750 T ERAT °C g4 -g4 70 (go 84 .19 .06 .06 .11 .30 .30 .19 .32 .54 1.21 .39 .37 .75 1.15 2.15 .47 .56 1.25 1.81 2.83 .55 .77 1.75 2.40 3.28 .62 .99 2.20 2.91 3.54 .69 1.20 2.58 3.31 3.70 .75 1.42 2.90 3.63 3.79 .81 1.62 3.15 3.86 3.84 .87 1.81 3.35 4.04 3.87 .92 2.00 3.50 4.17 3.88 .98 2.18 3.62 4.27 3.89 1.03 2.34 3.71 4.34 3.90 1.08 2.49 3.78 4.39 3.90 1.13 2.64 3.84 4.43 3.90 1.17 2.77 3.88 4.46 3.90 1.22 2.89 3.91 4.48 3.90 1.26 3.01 3.93 4.49 3.90 1.31 3.11 3.95 4.50 3.90 1.35 3.21 3.96 4.51 3.90 1.39 3.30 3.97 4.52 3.90 1.43 3.38 3.98 4.52 3.90 1.47 3.45 3.98 4.52 3.90 1.51 3.52 3.98 4.53 3.90 1.55 3.58 3.99 4.53 3.90 67 and C values are shown in Table 2. Calculated models were found to predict reasonably well the experimental data (CD = 0.95 to 0.99). and therefore were utilized to estimate the time required to achieve a preselected Y' (1.0. 2.0. 2.5. 3.0 and 3.5) for each temperature used. These values are shown in Table 3. The first range of values for Ea was calculated by plotting the Ln of time (sec) and the inverse of absolute temperature (Figure 4). This method of calculating Ea value assumes that the temperature of cooking is constant throughout the thermal process and that the sample attains the temperature of the process instantly. However. experimental values showed that the equilibrium temperature required a relatively long time. which is explained by the relatively low heat transmission coefficient of this protein solution. Experimental samples arrived at equilibrium temperature (bath temperature) at about 10 min. which is the time range where most of the thermal induced.changes in BEAV occurred. This explains why different time-temperature ranges produced different estimates of Ea. nevertheless these values indicated the range where the Ea values were to be found. Values of Ea found by this method (Table 4) ranged from 14.147 to 33.989 cal. This range agrees with reports from 66 Table 2. Calculated constant values for modeled experimental data cooked to five different temperatures. TEMPERATURE CONSTANT” 92 6 e 9 R_.‘-’ 54 4.603 0.2987e-3 0.679 0.964 64 3.995 0.3236e-2 1.774 0.991 70 3.997 0.9591e-2 3.046 0.952 60 3.950 0.15256-1 4.260 0.961 65 3.903 0.1940e-1 3.116 0.946 * A. B and C as defined by Equation 38; R8 = coefficient of determination. 69 Table 3. Time of cooking in seconds required to produce a selected thermal induced apparent viscosity for five different temperatures. APP T TEflEERATURE 2Q VISQQSITY §4 64 70 £0 94 1 O 374 181 105 83 54 2 O 1123 329 167 129 83 2.5 1760 421 203 135 104 3 0 2500 538 260 188 130 3 5 3690 710 329 227 174 mommy 0E; C4 Ln Time (sec) 70 9- 1 VEa=14.147 8" DE8=20,647 . 0Ea=22,669 7- 5.. 51 4- 0 17:13.5 ‘ o 11:25 3 v n=1.0 .........I..rTrr.r.,........r,r..-.....] 0.0027 0.0028 0.0029 0.0030 0.0031 1/T (.K) Figure 4. Estimation of activation energy range for five temperatures and three thermal—induced apparent viscosities (n). 71 Table 4. Estimated values for Ea (cal/moi) for different 1": and temperature ranges. TEMPERATURE HEAT-INDUCED APPARENT VISCOSITY RANGE _OC 1. 0 2. 0 2. 5 3. 0 3. 5 54 to 84 14. 147 18. 828 20. 647 21, 664 22. 669 64 to 70 17. 513 25. 391 30. 264 30. 292 33. 989 80 to 84 28, 469 27. 629 26. 429 24. 434 17, 610 72 Ziegler and Acton (1984) who reported that the apparent heat of activation for the heat mediated interaction of actomyosin is in the range of 17.1 to 27.0 Kcal and with Smith.gt al. (1988) who found that the activation energy for the thermal gelation of myofibrillar poultry proteins is 20.000 cal. The second step in calculating the Ea value was based on a second assumption of this experiment namely: The reaction extent (Y') is a function of the time-temperature history of the process (TTH). other factors constant. This is described by Equation 39. t Y'=F ( Ireflm dt ) (39) Equation 39 implies that Y' values are a function of the time—temperature history of the process. which.was one of the basic assumptions of this experiment. Graphically this relationship will produce (when selected Ea is correct) one single curve when experimental Y’ is plotted versus the time-temperature history of the process. independently of the temperature of the water bath. When Ea is incorrect. several curves (one for each temperature of processi will be PI‘O duc e d. 73 The range of values for Ea calculated previously (14,14? to 33.989 cal) where used as starting values. The TTH value of the thermal process of the myofibrillar beef proteins was calculated using a transient heat transfer model for infinite cylinders (Parker 53 3;, 1970). It predicted temperature-time data for ten different radial positions within a given test-tube cross-section based on the initial, center and bath temperatures for each treatment as described before. The cross-section was divided into ten concentric rings defined by the preselected radial position. TTH was computed for each ring and then used to compute a mass average TTH. Morgan 5; £9; (1987) demonstrated that this ‘method significantly reduces error in estimating Kinetic parameters. It more accurately accounts for the variation in reaction rates within a sample due to temperature-time profiles. They also concluded that using the center temperature-time data. which is normally used in lethality studies, results in errors commonly exceeding 100%. while using mass average temperature-time data results in greater than 50x error, compared to the technique 0f using concentric rings to compute Kinetic parameters. During the first stage of the gelation reaction. Y' is a linear function of Ln (TTH). This property was used to determine the Ea value. Those values of Y' that were in the linear region for five different processing temperatures (54, 54, 7°. 80 and 84 0C) were selected. These selected 74 experimental Y’ values were plotted against their corresponding TTH values utilizing different values for Ea. A linear regression analysis was performed each time a new value of Ea was used until a maximum linear coefficient of determination was obtained (CD: 0.96) when Ea had a value of 29,500 cal/mol. The relationship between experimental Y’ values and the values of the TTH model for the temperature range of 54 to 84 °C and for the Y' range of O to 3.5 is shown in Figure 5. The linear regression analysis is presented in Table 5. During this thermal analysis it was observed that the Y’ values for the thermal process at 54 °C lagged somehow behind values for higher temperatures (Figure 5). This suggested that another reaction with.higher Ea was exerting a significant influence at this temperature. Even though the overall heat mediated aggregation reaction has been reported to follow first order reaction. the interaction of sarcoplasmic protein molecules apparently proceeds through two steps. Acton 3; al. (1981) reported two temperature reaction zones for the formation of natural actomyosin aggregates in dilute solutions (0.5 mg/ml) and for the formation of continuous structural aggregates in more concentrated solutions (7.5 mg/ml). The second stage was associated with structural changes of the helical rod segment 0f 1111708111 W101! culminates in network formation Y. 75 1 4.. R’= 0.92 J 3.. 2- 1 - o - / o o I I I I I I I I I r I I I I I f I I I I I I -15.5 -15.0 -l4.5 -14.0 -13.5 Log TTH Figure 5. Correlation of Y‘ values obtained in the temperature range of 64 to 84°C and their estimated TTH value. 76 Table 5. Statistical analysis of the linear regression of experimental Y’ values and corresponding TTH values. Ea utilized was 29,500 cal/mol. A N A L Y S I S O F V A R I A N C E Source of Degrees of Sum of A Mean F Variation Freedom Squares Square Value Mean 1 137.5460 137.54600 Regression 1 18.4604 18.46035 250.2 Residual 23 1.6972 0.07379 Total 25 157.7036 $18. of F Value: .0000 R E G R E S S I 0 N S T A T I S T I C S Regression Standard Student's T Confidence Limits Coefficient Error Value Sig Lower .Upper 8(0) 31.70035 1.8567 17.07 .00 30.43 32.97 3(1) 2.05713 0.1301 15.82 .00 1.97 2.15 Coefficient of: Determination .916 Correlation .95 77 4 7 50:20.000 cal 34 °c so °c 70 °C 54 °C 54 ’C -7'.5 iliii W I I I I I I I I T -9.0 —8.5 -8.0 Log TTH Figure 6. Relationship between experimental values of Y' and the Log of TTH. 78 through cross-linking of these segments. HonteJano gt 3;. (1984) reported that a uniform and rapid increase in rigidity of myofibrillar beef proteins started at 56 °C. indicating the formation of stable. stiff and elastic structured matrix. Other reports also indicate this type of behavior (Ziegler and Acton. 1984; Liu gt a_l. 1982) and it is consistent with the proposed reaction mechanism for the formation of protein gels (Ferry. 1948). step 1 step 2 xPn ---------- > de --------- > (Pd)x where x is the number of protein molecules P. with n denoting native state and d denatured state. The helix to coil transformation starts at about 55 °C and is the starting point of polymerization and gelation. This will make the gelation process at 54 00 very slow and even though the overall reaction remains as a first order reaction. the predominant step (and.hence the activation energy) that will predominate will be that of some other reactions which.precede this step and start at lower temperatures (dissociation of F-actin and the conformational changes in the head of myosin). The test of the model using temperature values from 64 to 84 °C notably increased the value of the coefficient of 79 determination of the regression line (CD: 0.98 versus 0.92) and assigned to Ea a value 20.000 cal. This new linear relationship of the experimental values of Y’ and the values of TTH are shown in Figure 7. whereas the regression analysis 18 shown in Table 6. Experimental data suggest that the thermal gelation of myofibrillar proteins does not occur at any significant rate until the temperature of the process is above 54 °C and probably is not significant before 60 °C. This agrees with Yasui gt 3;. (1979) who reported that the gelation of myosin reaches a maximum at 60-70 °C and with Ziegler and Acton (1984) who concluded that the transition occurring at 55 °C is possibly the most crucial. since gels do not attain appreciable strength until this temperature is reached. This also agrees with commercial practice for meat products where the minimum temperature utilized to obtain a firm cooked product is about 65 °C. For these reasons. it was decided to consider only the temperature range of 64 to 84 °C. and therefore, to consider a final Ea value of 20.000 cal/mol. Determination 23 (a) The value (a) represents the product of the transmission coefficient (kt) and.the Boltzman's constant Yl 80 4. R2=0.98 Log' TTH . Figure 7. Correlation of Y' values obtained in the temperature range of 64 to 84 °C and their estimated TTH. 81 Table 6. Statistical analysis of the linear regression of experimental Y’ values and corresponding TTH values. Ea utilized was 20.000 cal/mol. A H A L Y S I S 0 F V A R I A N C E Source of Degrees of Sum of Mean F Variation Freedom Squares Square Value Mean 1 109.27810 109.278 Regression 1 16.07738 16.0774 921.0 Residual 18 0.31420 0.0175 Total 20 125.6697 Sig. of F Value: .0000 R E G R E S S I 0 N S T A T I S T I C 8 Regression Standard Student's T Confidence Limits Coefficient Error Value Sig Lower Upper 8(0) 23.34136 0.69271 33.70 .00 22.86 23.82 3(1) 2.55376 0.08415 30.35 .00 2.50 2.61 Coefficient of: Determination .981 Correlation .990 82 divided by Plank's constant or 2.83E+10 kt. Because (a) is an implicit constant (can not be isolated) to calculate its value an iteration process was required. If the basic model (Equation 15) is considered at two different reaction stages (stage 1 and 2) at a selected protein concentration. they could be expressed by Equations 40 and 41. )fi' = B(1-€'°"”')°' <40) (41) Y.’ = team-6“)“ The product 0f the division 0f Equations 40 and 41 gave the following expression: Y1 8(1_e-01TH.)¢ Y2 B(1-€’°"”‘)“ (42) Equation 42 could also be written as: Y1 B(1-€’°m')a .___ _ :: “A (43) Y2 B( 1 -e-°""')“ where H: 0 when the iterated value of (a) is correct. 83 Equation 43 indicates a relationship between (a) and a, therefore. its solution for (a) requires the predetermination of a. The value of a for myofibrillar beef proteins was not found in the literature. but Horgan g; 3;; (1987) reported that values of a for the gelation of proteins are in the range of 1 to 3. Preliminary experiments yielded tentative values of 0.52 and 0.80. Based on this. it was decided to calculate the value of (a) with these five different values of a (0.52. 0.8. 1.0. 2.0 and 3.0) and to obtain a graphic relationship between these tWO material constants. The value of (a) for each.a value. was calculated by an iteration computer subroutine which.gave values to (a) until the equality of Equation 43 was met (tolerance 1E-14). For this purpose 20 values of Y' ranging in values from 0.54 to 3.54 and their corresponding TTH value were selected from samples processed at 64. 70. 80 and 84 °C. These Y'-TTH values were sorted and divided in two groups (ten lower and ten higher) before being utilized in Equation 43. The calculated average (a) value and (kt) value for each preselected a 18 shown in Table 7. The value of (a) was found to have a power relationship with.a under the conditions of this experiment as shown in Figure 8 (CD: 0. 99). This mathematical relationship is expressed by Equation 44. 84 Table 7. Calculation of (a) and kt values using an average of 20 TTH values. Ea used was 20,000 cal/mol. A £§E§L is) 53 0.53 1.87e+7 8.98e-4 0.3 1.oae+a 4.91e-3 1.0 1.63e+8 7.84e-3 2.0 3.50e+8 1.68e-2 3.0 4.60e+8 2.21e-2 (a) 85 5E+08- /O / 4E+08— // / o/ / 3E+08- / / / 2E+08- / f 1E+08- /! / . J R _ 999 0 1 r I o 1 2 3 a Figure 8. Correlation between a and (a). 86 a = —0.114578 E(+10) + 0.13082 (E+10) alum“ ‘4‘“ The value of a and therefore of (a) required by the mathematical model was calculated by assigning to a the predetermined values of 0.5. 0.6. 0.7. 0.8. 0.9. 1.0. 2.0. 3.0. 5.0 and 8.0 followed by a calculation of their corresponding (a) value. A non-linear regression algorithm (Harquart. 1963) was utilized to fit the basic mathematical model (Equation 15) to experimental data using these sets of a and (a) values. The selected a-(a) combination was that which.produced.the best coefficient of determination. Experimental values were obtained from five different experimental units processed at a similar temperature (70 0C) and.with protein concentrations 0f 85.3. 31.9. 38.4. 41.5 and 46.2% (dry basis). The plot of the Ra’s determined for each.set of values of a and (a) and for each.protein concentration is shown in Figure 9. These results were not expected because they suggest that the values of a are a function of the protein concentration. when 1t W88 expected to be constant. T0 investigate this possible correlation. the values 0f 0 which.produced the best coefficient 0f determination 87 1.0— 0.9-4 o.8~ ‘ 0.7n 0.6- " v—v 46.2% protein .. H 38.4% protein ‘ H 31.9% protein .. o—o 25.3% protein 0 5 o—o 41.5% protein . . i 1 T l ' T ' f ' I Figure 9. PLot of 0: versus R’ for five protein concentrations. Protein concentration is in dry basis. 88 were plotted against their corresponding protein concentrations. It was found (Figure 10) that the values of a decrease exponentially as the value of protein concentration increases. This function is expressed by Equation 45. a = 0.734377 + 2074856 e'WW" (45) Where C is protein concentration (dry basis). Determination 93 A; The value of A' was estimated using the special case of the general model (Equation 15) for an infinite time of cooking. Under this conditions the value of the second term of the model tend to one and therefore the model could be simplified to: Yin = A' C (46) where C 18 protein concentration on a dry 133818 and A' and G are material constants. To calculate this parameter. data were obtained from five different experimental units thermally processed at similar time-temperatures conditions but with protein concentration on a dry basis varying between 25.3 and 44.62. 89 .1 _ R2=0.999 i 7 l _ i \ 7 l _ l i 7 \ fl \ \ 7 \ _ \ \ - \ _A \ \ - \ \ 7 \ \ 7 \ \‘—-__£__.o____ Ifi Ifi Ti T I I I I I I I I I I I I I I I I I I I I I 20 25 30 35 4O 45 Protein Concentration (0.0) Figure 10. Correlation between a and protein concentration (d.b.). 90 The thermally induced BEAV was calculated as mentioned before. The experimental data was fitted to the basic model (Equation 15) and Y’ at time infinite calculated using a non-linear regression algorithm (Marquard. 1963). A plot of the asymptotic values of Y' and their corresponding protein concentration (dry b8818) 18 presented in Figure 11. Equation 46 predicts the value of 7' at time infinite for any concentration of protein where gelation occurs and could be rearranged as: A' = Y. (47) Ce Calculated values of A’ were found to increase as protein concentration increased. A plot of these values (Figure 12) exhibited a A' values increasing exponentially with.an increase in protein concentration. Their calculated mathematical relationship is described by Equation 48. The dependency of A' on protein concentration as described in Equation 48 set the calculated TTH model for the thermal gelation of myofibrillar beef proteins as: Y'=A'Cla ( 1’0”“ )a (49) 91 7.0 -, 6.0- /' . 5.0— / 4.0- . I /a 3.0- . ~ / q / / 2.0- . / / ‘ / / 1.0— i/ ' R2: 0.998 0.0 I I I I I I I I I I I I I I I I I I I I I I I I I I I I Ii 20 25 30 35 4o 45 50 Protein Concentration (d.b.) Figure 11. Correlation between protein concentration and Y'oo Al 92 0.40- ? R’=O.997 0.30-4 .4 0 0.20-4 0.10- 0.00- e —.10 IIrIIIIIITrITIIIIIITIIIIIIIIIII 20 25 30 35 40 45 50 Protein Concentration (d.b.) Figure 12. Correlation between protein concentration and A' (d.b.= dry basis). 93 Where 7': heat induced BEAV: A': as describe by Equation 48: a : as describe by Equation 45; a : as describe by Equation 44; TTH : the time temperature history of the process; C : protein concentration in dry basis. Maggy The developed mathematical model (Equation 49) theoretically described the thermally induced back extrusion apparent viscosity of myofibrillar beef proteins. for samples thermally processed on the temperature range of 64 to 84°C and.have a protein concentration on a dry basis between 25.6 and 44.6%. According t0_this model. if the protein concentration is kept constant. the model should predict the value of the thermally induced BEAV as a variable of the time-temperature history of the process. This was tested as follows: Experimental samples from five different experimental units with an approximate protein concentration of 42.5% (dry basis) were cooked at 64. 69. 71. 80 and 84 °C and their Y' calculated as described earlier. Experimental Y' values were plotted against values predicted by the TTH model. The model was found to describe reasonably well (CD:0.94) the experimental Y' values obtained from.these experiments. Figure 13 shows experimental 7’ values and values predicted by the model against the time-temperature history of the process (TTH). 94 Figure 13. Experimental Y' values for temperature range of 64 to 84 0 versus values predicted by the TTH model. i 95 okl vmdnum 96 A second form of testing the model was by using the protein concentration as a variable (at a constant temperature). Under these conditions the model should predict the value of Y’ as a variable of the protein concentration. for any time of cooking. This was tested using three different experimental units with a protein concentrations on dry basis of 30.6. 38.4 and 46.2%. These samples were thermally processed at 69 °C. Experimental Y’ values and predicted Y's were plotted against the time-temperature history of the process and found to correlate reasonable well (R3: 0.89. 0.91 and 0.94 respectively). These correlations are shown in Figure 14. From.the information showed by Figures 13 and 14 it was concluded that under the conditions of this experiment. protein concentration on a dry basis in the range of 25.3 to 44.2% (dry basis) and a temperature in the range of 64 to 84 °C. the developed mathematical model (Equation 49) predicts the change in Y’ (and presumedly the thermal gelation of myofibrillar beef proteins) as a function of the protein concentration and.the time-temperature history of the process. Verification u; the Hodel A basic assumption of the model developed.was that the heat induced BEAV (Y') is a measure of the thermal gelation Y. 97 8‘ v R’=O.89 : o R’=0.91 7—i O R2=0.94 O a 0 I SJ 0 £— .. e e 0 5d 0 q o 4.. ‘ : . e e 31 . o .4 V e e v e 2- . V g 3— . v V 1 -( i/gi v 3% PROTEIN 3 e 4% PROTEIN 0 ‘ e 5% PROTEIN ' l I I I I l ' l ' I ' l 0 0 2.0 4 O 6.0 8.0 10.0 12.0 14.0 1TH (1E-8) Figure 14. Experimental Y' values for three different protein concentrations versus values predicted by the TTH model. 98 of myofibrillar beef proteins. To verify this assumption a parallel method of measuring the gelation reaction was sought. The extent of the thermal gelation of proteins can be measured in several ways namely: loss of solubility. increase in turbidity. reduction of water holding capacity. etc. (Acton and Dick. 1984). SameJima qt 3;. (1985) reported that the water holding capacity and gelation properties are the important factors that determine the quality of comminuted meat products. They also reported that these two properties are closely interrelated. The water holding capacity is a measure of the water released by the gel during the cooking process. When the thermally induced protein matrix is formed. water is trapped inside of the protein network. As the thermal process continues. an increase in the points of interaction occurs with a reduction of the interstitial space occupied by the trapped water. The net effect is a release of water which then indirectly measures the extent of the polymerization react 1011. The water released was determined on the ruptured gel/protein suspensions after gel strength testing. This technique warranted that the experimental units had the same Chemical composition and experimental treatment as 99 those for thermally induced BEAV. The experimental samples were obtained from protein solutions thermally processed at 70 °C and with two different protein concentrations (30.6 and 38.42. dry basis). The trend of experimental values of water released over time of cooking (Figure 15) showed a tendency very similar to the inverse of the basic TTH - Y' model described by Equation 38. The next step was to test if the change in water released during the thermal process could be described by the model developed for Y’. Experimental data confirmed the general knowledge that water holding capacity is inversely related to protein concentration. Because Y' and water holding capacity were inversely related. the mathematical model (Equation 49) to be fitted to the water released.had to be applied to the inverse of the protein concentration. Results showed (Figure 16) that the experimental values of water released closely correlate with values predicted by the basic model. Coefficients of determination were 0.99 and 0.97 for protein concentration on a dry basis of 30.6 and 38.4% respectively. The correlation between water released and the TTH model support the hypotesis that the thermally induced gelation of myofibrillar beef proteins is measured by the WATER RELEASED (g/lOg) 100 _______ :__________1 U D a D 4% PROTEIN v 3% PROTEIN I I I I I I 2000 3000 4000 TIME (sec) Figure 15. Relationship of water released and time of cooking for two protein concentrations. WATER RELEASED (g/ 1 09) 101 o R’=0.993 o R’=0.982 4- —_—___3 ———————— o . é/E D 3- l l J i __°.___.______° l ° 2— 1 /° - / 1 lo 1 l o/ l / 1°! 1- l l i I l ,1) III, a 39: PROTEIN 4% PROTEIN 0-4 I 1 I o I f I I I T'l'l',l' l 0.0 2.0 4.0 6.0 8.0 10 12 14 16 TTH (1E-8) Figure 16. Experimental water released values versus values predicted by the TTH model. 102 Instron back-extrusion apparent Viscosity. This correlation supports the hypothesis that the gelation process is a function of the protein concentration and the time-temperature history of the process. It also supports a basic premise of this experiment. i.e.. The thermal gelation of myofibrillar beef proteins could be predicted by the TTH model described by Equation 49. Effect 2; Vegetable Gums It was theorized.that the addition of vegetable gums to myofibrillar beef proteins solutions will have the effect of increasing the equivalent protein concentration. and therefore. alter the final three dimensional protein network of the thermally-produced gel. Vegetable gums are polysaccharides with different molecular weights. basic unit composition and level of side-branching. but in general they are more homogeneous and have more polar groups than myofibrillar proteins. These polar groups are responsible for the high.water holding capacity exhibited by these compounds. They may also serve as linking points between gums and myofibrillar beef proteins. therefore. helping in the creation of the three dimensional network of the thermally-induced gel produced by myofibrillar beef proteins. 103 If vegetable gums interact with myofibrillar proteins they should increase the apparent viscosity induced by the thermal process. This will show up as an apparent increase in the protein concentration (C) and the degree of polymerization (A’). and produce a more orderly entanglement (reduction of a). To test these assumptions the following experiment was carried out: An extracted myofibrillar beef protein solution with a protein concentration of 29.9% (dry basis) was divided into five lots. Each lot received 0.5% of a selected vegetable gum (carrageenan. guar, locust bean or xanthan gum) and was thermally processed at 70 °C. The TTH. Y’ and water released values were then calculated as mentioned before. Experimental Y’ for all protein-gum combinations were plotted against their corresponding TTH values and the mathematical model developed for myofibrillar proteins (Equation 49) fitted to each of them. Figures 17 to 20 show plots of experimental Y' against TTH values for each gum as well as values predicted by the TTH model. The Y' at time infinite for each protein-gum combination was calculated DY fitting Equation 48 t0 the experimental data by means Of a non-linear regression algorithm.(Harquard. 1963). The equivalent protein YI 104 5.01 4.0- A A T__—————A' ——————— -l f A A ‘1,“ A 2 3.0- i l q l l l 20 I ‘ _ l 4 . A 1.... ,1 l _ I l R’ = .912 l 0.0 I T T I fi . I I I I I I 1 I l 0 1 2 3 4 5 6 TTH (1E-7) Figure 17. Experimental Y' values for carrageenan-protein solution and values predicted by the TTH model. YO 105 5.0- 1 4.0— A A " A A A ——————————————— -a 3.0- A a 1%: A . A q 4 2.0- : j". q 1.04 'l l . l l 1?2 — .85 1 0'0 '1'1'1'1'1'1' 0 1 2 3 4 5 7714 (15-7) Figure 18. Experimental Y' values for guar- protein solution and values predicted by the TTH model. YI 106 5.0— 4.0-1 4 A A A A A AA _______________ 3.0— A if“. / A A A A/ A . I A I A P 2.0- l i, ‘ ‘ 1. 1' 1.0-4 i l - l i R2 = .904 0'0 l I F l I I i 0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 1TH (1E-7) Figure 19. Experimental Y' values for locust bean -protein solution and values predicted by the TTH model. Y. 107 1.5- 1 1.0-1 ‘ A q A A ”,..—-— III l””’ A . A /// - A / A , A / 05- 2A? A - his” g A q P l q l l R’ .. .77 0.0 I 4 I I I I I I I l T I I O 1 2 3 4 5 TTH (1E—7) Figure 20. Experimental Y' values for xanthan- protein solution and values predicted by the TTH model. 108 concentration was calculated as the hypothetical protein concentration which would be required to produce the same value Of Y' after an infinite time Of cooking. The calculated equivalent protein concentrations were used to determine their corresponding A’ and a values using Equations 45 and 48. Calculated equivalent protein concentration. A' and a for the protein-gum solutions are presented in Table 8. Relative change in a as affected by the different protein-gum combinations is shown in Figure 21. Carrageenan gum was found to contribute to the protein-gum system by increasing the strength of the cooked gel by 184.8% over that produced by the control. This meant an increase in equivalent protein concentration of 121.2% and a concomitant reduction of a of 19.4% (Table 8). Carrageenan gum increased the water holding capacity by a 130.7% over the control but had the lowest effect on water holding capacity of any of the gums evaluated in this experiment (Figure 22). This agrees in part with Wallingford and Labuza (1983) who reported that carrageenan gum had the second.highest water binding capacity (WBC) of nine gums in low fat meat emulsions studied. Foegeding and Ramsey (1986) reported.that carrageenan gum used at 1% with a 13% protein meat batter increased the force to fracture (FF). the hardness (H1) and the water holding capacity of 109 Table 8. Calculated values of equivalent protein concentration. a and A' for selected gum-protein combinations. GUM Y' C+ a A'__ Control 1.82676 32.66 0.9186 0.0706 Carrageenan 3.37684 39.68 0.7403 0.2180 Guar 3.64221 40.11 0.7389 0.2306 Locust bean 3.02690 38.39 0.7461 0.1894 Xanthan 0.77900 7.76 43796 1.326E-17 + Concentration Of protein (dry basis) . 7//////////////////A ”ZZZ? / 21. Effect of protein-gum combination on a. d 1dl.—111-llq - a O O 0 0 O 8 6 4 2 100- 6 20 moz_.—<...wm Figure 111 cocx / 0 .. 7/ coo . 8.....3 Z q _ 4 _ . _ _ . O 0 O 0 0 0 0 8 6 4 2 ommfibum 15.35 u>_._.<._um Figure 22. Water released by four gum-protein combinations (75 min at 70°C). 118 frankfurters. They concluded.that among other gums studied. carrageenan was the most beneficial in manufacturing low fat frankfurters. When calculated model constants were introduced in the TTH model it was found that the TTH model predicted reasonably well (R3=0.912) the change of Y of this protein-gum solution as a function of the time- temperature hiStOI‘Y Of the process, as shown in Figure 17. Guar gum increased the strength of the cooked gel by 193.9% over that produced by the control. The protein samples containing guar gum had the highest Y’ among the gum-protein combinations used in this experiment. The increase in equivalent protein concentration was 122.8% whereas a was decreased by 19.7% (Table 8). Guar gum increased the water holding capacity by 138.94% over the control and was ranked.third. This seems to disagree with.vallingford and Labuza (1983) who reported that guar gum had approximately two-thirds of the WBC of carrageenan. but because carrageenan gum is not a single homogeneous compound but rather a.heterogeneous mixture of several different polysaccharides. it is possible that their sample was different than the one used in this experiment. Foegeding and Ramsey (1986) reported that the addition of guar gum to low fat frankfurters reduced force to fracture (FF) and hardness DY almost 507.. While 0111" PQSUItS appear 113 not to support their findings, a direct comparison between studies is difficult because variations in ingredients and techniques. The calculated TTH model for the protein-guar solution acceptably predicted (Ra: 0.86) the change of Y' over time of cooking as shown in Figure 18. Locust bean gum increased.the strength of the cooked gel by 166.6%. This value is lower than that produced by carrageenan and guar gums but this gum still produced an increase in equivalent protein concentration of 117.6%. with a concomitant reduction in a of 18.9% (Table 8). Locust bean gum increased.the water holding capacity the protein-gum solution by 140.19% (Figure 22). The increase in water-retained during the cooking process induced by this gum was slightly lower than that produced by xanthan gum. This result supports the findings of Foegeding and Dayton (1986) who reported that xanthan and locust bean gums produced the lowest weight loss during cooking among several meat-gums combinations. The calculated mathematical model described reasonably well (R3: 0.904) the change in Y' due to the time-temperature history of the process as indicated in Figure 19. 114 Xanthan gum was found to behave as an inhibitor of the gelling phenomenon. Gel strength of the xanthan-protein solution was found to be only 42.6% of that produced by the control. This value of Y’ is outside of the limits of the mathematical model described by Equation 49 and therefore the equivalent protein concentration (70.8%) and a (93.3%) were calculated only as an exercise (Table 8). The water holding capacity of the xanthan gum-protein solution was the best of all experimental units (Figure 22) showing an increase of 146.3% over the control. Similar findings have been reported by Whiting (1984). who found that xanthan gum added at 0.1 or 0.3% decreased cooking losses and gel strength. It also agrees with.vallingford and Labuza (1983) who described xanthan gum.as the best water binder among several gums studied. SUMMARY AND CONCLUSIONS The objectives of this study were to develop a mathematical model for predicting the effects of time-temperature history and protein concentration in the thermal gelation of myofibrillar beef proteins as well as the interaction of these proteins with selected hydrocolloids. Thermal gelation of myofibrillar beef proteins was measured as the thermally-induced Instron back-extrusion apparent viscosity (Y’). water holding capacity was used as parallel method of measuring gelation and to verify the model developed for Y'. The developed mathematical model has an Ea for the thermal gelation of myofibrillar beef proteins of 20.000 cal/mol. Basic model constants (A'.a and a) were found to be mathematically related to protein concentration. these mathematical relationships were developed and integrated into the basic model. Experimental values Of Y' and WHC obtained under the 115 116 conditions of this experiment support the hypothesis that the proposed mathematical model (Equation 49) can be used to describe the thermally-induced gelation of myofibrillar beef proteins as a function of the protein concentration (dry basis) and the time-temperature history of the process. It was also found that the TTH model could be used to predict the water released during the thermal treatment as a function of the protein concentration and the time- temperature history of the process. The TTH model was shown to describe reasonably well the thermal gelation of solutions of myofibrillar beef proteins and selected vegetable gums. Under the conditions of this experiment xanthan gum was found to inhibit gelation. and therefore. the TTH model could not be applied to this protein-gum 80111121011. More research is needed to study the effect of other ingredients normally found in meat products (salts. lipids. connective tissue. etc.) in the mathematical model. as well as the relationship between back-extrusion apparent viscosity and sensorial attributes of thermally gelled meat products. 117 Fundamental knowledge of effects of temperature-time history in meat gels should enhance the understanding of the reaction kinetics involved in the thermally-induced gelation process. This TTH model can be useful in studying and predicting effects of process conditions on product quality and significantly reduce experimental cost and time. BIBLIOGRAPHY A.0.A.C. 1985. "Official Methods of Analysis.". Association of Official Agricultural Chemists. Washington. D.C. Aha. El-Baklg Ho Ho ’ ASK”. A. . E1 DaShIOUtY no So and E1 Ebzary. H.M. 1981. Characteristics of sausages prepared with alginates and alginates casings. Fleischwirtschaft. 61:1709. Acton. J.C. 1972. Effect of heat processing on extractability of salt-soluble protein. tissue binding strength and cooking loss in poultry meat loaves. J. Food Sci. 37:244. Acton, J.C. and Dick. R.L. 1984. Protein-protein interaction in processed meats. Proc Ann. Recip. Heat Conf. 37:36. Acton. J.C., Hanna. H.A. and Satterlee. L.D. 1981. Heat—induced gelation and protein-protein interaction of actomyosin. J. Food Biochem. 6:101. Acton. J. C. and Saffle. R.L. 1969. Preblended and prerigor meat in sausage emulsions. Food Technol. 23(3):367. Acton. J.C.. Ziegler. G.R. and Burge. D.L. 1983. Functionality of muscle constituents in the processing of comminuted meat products. CRC Critical Reviews Food Sci. Nut. 18:99. Andres. C. 1976. Processor’s guide to gums - Part 1. Food Process. 12:31. Anglemier. A.F. and Montgomery. u.w. 1976. Aminoacide. peptides. and proteins. In: "Principles of Food Science. Part I: Food Chemistry.“ 0.R. Fennema. Ed.. Harcel Dekker. Inc. NY. p. 238. Ashgar. A. and Pearson. A.H. 1980. Influence on ante- and post- mortem treatments upon muscle composition and meat quality. Adv. Food Res. 26:63. Asghar. A.. SameJima. K. and Yasui.T. 1985. Functionality of muscle proteins in gelation mechanisms of restructured.meat products. Crit. Rev. Food Sci. Hut. 22:1. Ashton Tate. Inc. 1985. Framework II. Torrance. CA. 118 119 Bandman. E. 1987. Chemistry of animals tissues. Proteins. In: "The Science of Heat and Meat Products." 3rd. ed. J.F. Price and 3.8. Schweigert. Eds. Food and Nutrition Press. Inc. Westport. CT. Bendall. J.R. 1964. Heat proteins. In: ”Symposium.on Foods: Proteins and Their Reactions.” H.W. Schultz and A.F. Anglemier. Eds. AVI Publishing Company. Westport. CT. p. 226. Blum. J.J. 1960. Interaction between myosin and its substrates. Arch. Biochem. Biophys. 87:104. Bodwell. C.E. and McClain. P.E. 1971. Chemistry of animal tissue. In: "The Science of Heat and Meat Products." 1st. ed. J.F. Price and 8.8. Schweigert. Eds. Freeman. San Francisco. p. 78. Bornstein. P. and Sage. H. 1980. Structurally distinct collagen types. Ann. Rev. Biochem. 49:97. Deng. J.. Toledo. R.T. and Lillard. D.A. 1976. Effect of temperature and pH on protein-protein interaction in actomyosin solutions. J. Food Sci. 41:273. Egelandsdal. B. 1980. Heat-induced gelling in solutions of ovalbumin. J. Food Sci. 46:670. Eisele. T.A. and Brekke. C.J. 1981. Chemical modification and functional properties of acylated beef heart myofibrillar protein. J. Food Sci. 46:1095. Eisensmith. S. 1986. Plotit an integrated graph-statistical package. Scientific Programming Enterpresis. Haslet. HI. Eyring. H. and Stearn. A.E. 1939. The application of the theory of absolute reaction rates to proteins. Chem. Rev. 24:263. Ferry. J.D. 1948. Proteins gels. Adv. Protein Chem. 3:1. Ferry. J.D. 1970. Visco-Elastic Properties of Polymers. and ed. John Wiley and Sons. Inc. NY. Foegeding. E.A.. Allen. C.E. and Dayton. v.3. 1983. Thermally induced gelation and interactions of myosin. albumin and fibrinogen. Proc Ann. Recip. Heat Conf. 36:190. Foegeding. E.A. and Ramsey. S.R. 1986. Effect of gums on low-fat meat batters. J. Food Sci. 61:33. 120 Ford. A. L.. Jones. P. 11.. nacFarlane. J. J.. Schmidt. 6. E. and Turner. R.H. 1978. Binding of meat pieces: Objective and subjective assessment of restructured steakettes containing added.myosin and/or sarcosplasmic protein. J. Food Sci. 43:816. Forrest. J.C.. Aberle. E.D.. Hedrick. H.B.. Judge. H.D. and Herkel. R.A. 1976. Principles of Heat Science. W.H. Freeman and Co.. San Francisco. CA. Fox. J.B.. Ackerman. S.A. and Jenkins. R.K. 1983. Effect of anionic gums on the texture of pickled frankfurters. J. Food Sci. 43:1031. Fredericksen. D.w. and Holtzer. A. 1968. The substructure of the myosin molecule. Production and properties of the alkali subunits. Biochem. 7:3936. Fukazawa. T.. Hashimoto. Y. and Yasui. T. 1961a. Effect of some proteins on the binding quality of an experimental sausage. J. Food Sci. 26:641. Fukazawa. T.. Hashimoto. Y. and Yasui. T. 1961b. The relationship between the components of myofibrillar protein and the effect of various phosphates that influence the binding quality of sausage. J. Food Sci. 26:660. Gard. S.L.. Bell. P.B. and Lazarides. E. 1979. Coexistence of desmin and.the fibroblastic intermediate filament subunit in muscle and nonmuscle cell. Proc. Natl. Acad. Sci. USA. 76:3894. Gillett. T.A.. Heiburg. D.E.. Brown. C.L. and Simon. S. 1977. Parameters affecting meat protein extraction and interpretation of model system data for meat emulsion formation. J. Food Sci. 42:1606. Goldstein.A.H. and.Alter. E.N. 1973. Guar gum. In: "Industrial Gums." R.L. Whistler. Ed. Academic Press. HY. p0 3210 Gossett. P.W.. Rizvi. S.S.H. and Baker. R.C. 1984. Quantitative analysis of gelation in egg protein systems. Food Technol. Ho. 6:67. Grabowska. E.J. and Sikorski. z.E. 1976. The gel forming capacity of fish.myofibrillar proteins. Lebensm. Wiss u Technol. 9:33. Gracia-Hunzi. H. and Franzini-Armstrong. C. 1980. Molecular network in adult skeletal muscle. J. Ultrastruct. Res. 73:21. 121 Granger. B.L. and Lazarides. E. 1978. The existence of an insoluble Z-disc scaffold in chicken skeletal muscle. Cell. 16:1263. Granicher. D. and Portzehl. H. 1964. The influence of magnesium and calcium pyrophosphate chelates of free magnesium ions. free calcium ions. and free pyrophosphate ions on the dissociation of actomyosin in solution. Biochim. Biophys. Acta 86:667. Hanson.J. and Lowy. J. 1963. The structure of F-actin and of actin filaments isolated from.muscle. J. Hol. Biol. 6:48. Hanson. J. and Lowy. J. 1964. The structure of actin. In: "Biochemistry of Huscle Contraction." J. Gergely. Ed.. Little Brown and Co.. Boston. HA. p. 141. Harper. J.H.. Rhodes. T.P. and.Wanninger. L.A. 1971. Viscosity model for cooked cereal doughs. Amer. Inst. Chem. Engl. Symp. Serv. No. 108. Harper. J.P.. Suter. D.A.. Dill. C.W. and Jones. E.R. 1978. Effects of heat treatment and protein concentration on the rheology of bovine plasma protein suspensions. J. Food Sci. 43:1204. Haschemeyer. R.H. and Haschemeyer. A.E.V. 1973. Proteins. John Wiley and Sons. NY. p. 363. Hay. J.D.. Currie. R.W. and.Wolfe. F.H. 1973. Effect of postmortem aging on chicken muscle fibers. J. Food Sci. 38:981. Heldman. D.R. 1976. "Food Process Engineering". The Avi Publishing Co.. Inc. Westport. CT. Hermansson. A.H. 1978. Physicochemical aspects of soy proteins structure formation. J. Text. Stud. 9:36 Hermansson. A.H. 1979. Aggregation and denaturation involved in gel formation. In: ”Functionality and Protein Structure". A. Pour—El. Ed.. ACS Symp. Series 92. p. 81. Am. Chem. Soc.. Washington. D.C. Hermansson. A. H. 1982. Gel characteristics-compression and penetration of blood plasma gels. J. Food Sci. 47:1960. Hickson. D.W.. Dill. C.W.. Horgan. R.G.. Sweat. V.E.. Suter. D.A. and Carpenter. z.L. 1982. Rheological properties of two heat-induced protein gels. J. Food Sci. 47:783. 122 Ishioroshi. H.. Samejima. K.. Arie. Y. and Yasui. T. 1980. Effect of blocking the myosin-actin interaction in heat-induced gelation of myosin in the presence of actin. Agric. Biol. Chem. 44:2186. Ishioroshi. H.. Samejima. K. and Yasui. T. 1979. Heat-induced gelation of myosin: Factors of pH and salt concentrations. J. Food Sci. 44:1280. Ishioroshi. H.. Samejima. K. and Yasui. T. 1982. Further studies on the roles of the head and tail regions of the myosin molecule in heat-induced gelation. J. Food Sci. 47:114. Kauzmann. W. 1969. Some factors in the interpretation of protein denaturation. Adv. Protein Chem. 14:1. Lawrie. R.A. 1974. "Heat Science”. 3rd. ed. Pergamon Press. HY. Lazarides. E. 1982. Intermediate filaments: A chemically heterogeneous. developmentally regulated class of proteins. Annu. Rev. Biochem. 61:219. Lim. S.T. and Botts. J. 1967. Temperature and aging effects on the fluorescence intensity of myosin-ANS complex. Arch. Bioch. Biophys. 122:163. Liu. Y.H.. Lin. T.S. and Lanier. T.C. 1982. Thermal denaturation and aggregation of actomyosin from Atlantic croaker. J. Food Sci. 47:1916. Locker. R.H. and Leet. H.G. 1976. Histology of highly-stretched beef muscle. J. Ultrastruct. Res. 62:64. Luikov. A.V. 1968. ”Analytical Heat Diffusion Theory". Academic Press. NY. Lund. D.B. 1976. Heat processing. In: "Principles of Food Science. Part II. Physical Principles of Food Preservation.” 0.R. Fennema. Ed. Marcel Dekker. Inc. HY. p. 28. HacFarlane. J. J.. Schmidt. G. R. and Turner. R. H. 1977. Binding of meat pieces: A comparison of myosin. actomyosin and sarcosplasmic proteins as binding agents. J. Food Sci. 42:1603. Harquardt. D.W. 1963. An algorithm for least squares estimation of non-linear parameters. SIAH J. 11:431. Haruyama. I. 1980. Elastic structure of connectin in muscle. In: "Huscle Contraction: Its Regulatory Hechanisms." S. Ebashi. I. Haruyama and H. Endo. Eds. Japan Scientific Societies Press. Tokyo. p. 4. _.__.i' “Pr: - -.-A:‘.’-AHA 123 Haruyama. K. and Ebashi. S. 1970. Regulatory protein in muscle. In: ”Physiology and Biochemistry of Huscle as Food." E.J. Briskey. R.G. Cassens and B.B. Harch. Eds. Univ. of Wisconsin Press. Hadison. WI. p. 119. HcHeely. W.H. and Hang. K.S. 1973. Xanthan and some other biosynthetic gums. In: "Industrial Gums.” R.L. Whistler. Ed. Academic Press. HY. Hiller, A.J.. Ackerman. S.A. and Palumbo. S.A. 1980. Effects of frozen storage on functionality of meat for processing. J. Food Sci. 46:1466. Hiyanishi. T. and Tonomura. Y. 1981. Location of the non-identical two reactive lysine residues in the myosin molecule. J. Biochem.. (Tokyo) 89:831. Hontejano. J.G.. Hamann. D.D. and Lanier. T.C. 1984. Thermally induced gelation of selected comminuted muscle systems-rheological changes during processing final strengths and microstructure. J. Food Sci. 49:1496. Horgan. R.G. 1979. Hodelling the effects of temperature-time history. temperature. shear rate and moisture on viscosity of defatted soy flour dough. Ph. D. Dissertation. Agricultural Engineering. Texas A&H University. College Station. Horgan. R.G.. Steffe. J.F. and Ofeli. R.Y. 1988. A generalized viscosity model for extrusion of protein doughs. Submitted to J. Food Proc. Eng. Horris. E.R.. Rees. D.A.. Young. 6.. Walkinshaw. H.D. and Darke. A. 1977. A role for polysaccharide conformation in recognition between Xanthomonas pathogen and its plant host. J. Hol. Biol. 110:1. Hurray, J.H. and Weber. A. 1974. The cooperative action of muscle proteins. Sci. Amer. 230(2):69. Hakayama. T. and Sato. Y. 1971a. Relationship between binding quality of meat and myofibrillar proteins. Part II. The contribution of native tropomyosin and actin to the binding quality of meat. Agr. Biol. Chem. 36(2):208. Hakayama. T. and Sato. Y. 1971b. Relationships between binding quality of meat and myofibrillar proteins. Part III. Contributions of myosin A and actin to rheological properties of heat minced-meat gel. J. Text. Studies. 2:76. Hiwa. E. 1976. Role of hydrophobic binding in gelation of fish.flesh paste. Bull. Jap. Soc. Sci. Fish. 41:907. 184 Obinata. T.. Haruyama. K.. Sugita. H.. Kohama. K. and Ebashi. S. 1981. Dynamic aspects of structural proteins in vertebrate skeletal muscle. Huscle Herve 4:466. Parker. J.D.. 30388, J.B. and 3110K. E.F. 1970. "Introduction t0 FlUld Hechanics and Heat Transfer." Paul. P.C. 1972. Proteins. enzymes. collagen and gelatin. Ch. 3. In: "Food Theory and Applications.“ P.C. Paul and H.H. Palmer. Eds. John Wiley and Sons. Inc.. New York. NY. Paul. P.C. and Palmer. H.H. 1972. Colloidal system and emulsions. In: "Food Theory and Applications." P.C. Paul and H.H. Palmer. Eds. John Wiley and Sons. Inc. NY. p. 77. Pedersen. J.K. 1980. Carrageenan. pectin and locust bean gums gels. Trend in. Their food use. Food.Chem. 6:77. Penny. I.F. 1967. The influence Of pH and temperature on the properties Of myosin. Biochem. J. 1043509. Perry. S.V. 1966. Relation between chemical and contractile function and structure of the skeletal muscle cell. Physiol. Rev. 36:3. Pollard. T.D.. Aebi. U.. Cooper. J.A.. Fowler. W.E. and Tseng. P. 1981. Actin structure. polymerization and gelation. Cold Spring Harbor Symp. Quant. Biol. 46:613. Portter. J.B. 1974. The content of troponin. tropomyosin. actin and myosin in rabbit skeletal muscle myofibrills. Arch. Biochem. Biophys. 162:436. Porzio. H.A. and Pearson. A.H. 1977. Improved resolution of myofibrillar proteins with sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Biochim. Biophys. Acta 490:27. Price. H. and Sanger. J.W. 1979. Intermediate filaments Z-disks in adult chicken muscle. J. Exp. Zool. 208:263. Price. H. and Sanger. J.W. 1980. Intermediate filaments are redistributed during myogenesis and become associated with z-disks and membranes. J. Cell Biol. 87:182a. Quinn. J.R.. Raymond. D.P. and Harwalkar. V.R. 1980. Differential scanning calorimetry of meat proteins as affected by processing treatment. J. Food Sci. 46:1146. Randall. C.J. and.Voisey. P.W. 1977. Effect of meat protein fractions on textural characteristics of meat emulsions. J. Inst. Sci. Technol. Aliment. 10(2):88. 11' fl. MHz-p" 125 R01. F. 1973. Locust bean gum. In: " Industrial Gums.” R.L. Whistle. Ed. Academic Press. NY. p. 361. Samejima. K.. Egelandsdal. B. and Fretheim. K. 1986. Heat gelation properties and protein extractability of beef myofibrils. J. Food Sci. 50:1640. Samejima. K.. Hashimoto. Y.. Yasui. T. and Fukasawa. T. 1969. Heat gelling properties of myosin. actin. actomyosin and myosin-subunits in a saline model system. J. Food Sci. 34:242. Samejima. K.. Ishioroshi. H. and Yasui. T. 1981. Relative roles of the head and tail portions of the molecule in the heat-induced gelation of myosin. J. Food Sci. 46:1412. Samejima. K.. Yamauchi. H.. Asghor. A. and Yasui. T. 1984. Role of myosin heavy chains from rabbit skeletal muscle in the heat-induced gelation mechanism. Agric. Biol. Chem. 48:2226. Scheraga. H.A. 1963. Intramolecular bonds in proteins. II. Non-covalent bonds. In: "The Proteins. Vol. 1..” Neurath. H.. Ed. Academic Press. NY. p. 478. Schmidt. G.R. 1987. Functional behavior of meat components in processing. In: ”The Science of Heat and Heat Products”. 3rd ed. J.F. Price and B.S. Schweigert. Eds. Food and Nutrition Press. Inc. Westport. CT. p. 413. Schmidt. G.R.. Hawson. R.F. and Siegel. D.G. 1981. Functionality of a protein matrix in comminuted meat products. Food Technol. 6:236. Schut. J. 1976. Heat emulsions. In: ”Food Emulsions." Ferberg. 8.. Ed. Harcel Dekker. Inc. NY. p. 79. Scopes. R.H. 1970. Characterization and study of sarcosplasmic proteins. In: ”The Physiology and Biochemistry of Huscle as Food. Vol.2.” Briskey. E.J.. Cassens. R.G. and Harch. B.B.. Eds. University of Wisconsin Press. p. 471. Sender. P.H. 1971. Huscle fibrils: Solubilization and gel electrophoresis. FEBS Letters 17:106. Shah. B.H. and Darby. R. 1976. Prediction of polyethylene melt rheological properties from.molecular weight distribution data obtained by gel permeation chromatography. Poly. Eng. Sci. 16:8. Shimada. I. and Hatsushita. S. 1981. Effects of salts and denaturants on thermocoagulation of proteins. J. Agric. Food Chem. 29: 16. 126 Siegel. D.G. and.Schmidt. G.R. 1979. Ionic. pH and temperature effects on the binding ability of myosin. J. Food Sci. 44:1686. Siegel. D.G.. Theno. D.H. and Schmidt. G.R. 1978. Heat massaging: The effect of salt. phosphate and massaging on the presence of specific skeletal muscle proteins in the exudate of a sectionated and formed ham. J. Food Sci. 43:327. Sjostrand. F.S. 1962. The connections between A- and I-band filaments in striated frog muscle. J. Ultrastruct. Res. 1:226. Smith. D.H. 1987. Functional and biochemical changes in deboned turkey due to frozen storage and lipid oxidation. J. Food Sci. 62:22. Smith. D.H.. Horgan. R.G. and Alvarez. V.B. 1988. A generalized mathematical model for predicting heat-induced chicken myofibrillar protein gel strength. J. Food Sci. Vol No 63: In Press. Smith. D.H.. Salih. A.H. and Horgan. R.G. 1987. Heat treatments effects on warmed-over flavor in chicken breast meat. J. Food Sci. 62:842. Software Arts Inc. 1983. TKISolver. Scotts Valley. CA. Steiner. R.F.. Laki. K. and Spicer. S. 1962. Light scattering studies on some muscle proteins. J. Polymer Sci. 8:23. Stoloff. L. 1973. Carrageenan. In: " Industrial Gums.” R.L. Whistle. Ed. Academic Press. NY. p. 83. Szent-Gyorgyi. A.G. 1961. Chemistry of Huscular Contraction. 2nd Ed. Academic Press. NY. Tanford. C. 1968. Protein denaturation. Adv. Prot. Chem. 23:121. Turner. R.H.. Jones. P.N. and HacFarlane. J.J. 1979. Binding of meat pieces: An investigation of the use myosin-containing extracts from pre- and post-rigor bovine muscle as meat binding agents. J. Food Sci. 44:1443. Wallingford. L. and Labuza. T.P. 1983. Evaluation of the water binding properties of food.hydrocolloids by physical/chemical methods in a low meat emulsion. J. Food Sci. 48:1. 127 Wang. K. and Ramirez-Mitchell. R. 1983. A network of transverse and longitudinal intermediate filaments is associated with sarcomeres of adult vertebrate skeletal muscle. J. Cell Biol. 96:662. Williams. D.J. 1971. Polymer Science in Engineering. Prentice-Hall. Inc. Englewood Cliffd. NJ. Whiting. R.C. 1984. Addition of phosphates. proteins and gums to reduce-salt frankfurters batters. J. Food Sci. 48:1. Wolosewick. J.J. and Porter. E.R. 1979. Hicrotrabecular lattice of the cytoplasmic ground substance. J. Cell Biol. 82:114. Wright. D.J.. Leach. J.B. and.Wilding. P. 1977. Differential scanning calorimetric studies of muscle and its constituent proteins. J. Sci. Food Agr. 28:667. Yasui. T.. Ishioroshi. H.. Nakano. H. and Samejima. K. 1979. Changes in shear modulus. ultrastructure and spin-spin relaxation times of water associated with heat—induced gelation of myosin. J. Food Sci. 44:1201. Yasui. T.. Ishioroshi. H. and Samejima. K. 1980. Heat-induced gelation of myosin in the presence of actin. J. Food Biochem. 4:61. Yasui. T.. Ishioroshi. H. and Samejima. x. 1982. Effect of actomyosin on heat-induced gelation of myosin. Agric. Biol. Chem. 46:1049. Yates. L.D. and Greaser. R.L. 1983. Quantitative determination Of myosin and actin in rabbit skeletal muscle. J. Hol. Biol. 168:123. Ziegler. G.R. and Acton. J.C. 1984. Heat-induced transitions in the protein-protein interaction of bovine natural actomyosin. J. Food Biochem. 8:26. APPEND I CES APPENDIX A. List of the computer program Rodrigo. 100 REM "it: PROGRAM RODRIBO it!" 200 CLS e DISP " PROGRAM RODRIGO BY CARLOS A. LEVER" 300 REM "3 Program to Calculate Area, Apparent Viscosity, Apparent Elasticity and Shear Rate at the TNS from Back Extrusion Data 3” 400 DISP "TURN PONER ON" @ GOSUB 9900 8 CLEAR 500 REM tit! INSTROM CONTROL COMMANDS t!!! 600 DISP "Attach Plunger, set distance from envil= 3 cm. " GOSUB 9900 @ CLEAR 700 DISP "Press 81 then 0 ” e GOSUB 9900 @ CLEAR 800 DISP "Set Recorder Paper, Turn on line, CHart & servo." G BOSUB 9900 G CLEAR 900 DISP "Press LOAD CAL " 8 GOSUB 9900 8 CLEAR 1000 DISP "Press LOAD BAL (ENTER) " e GOSUB 9900 e CLEAR 1100 DISP "Press IEEE (ENTER) " G BOSUB 9900 8 CLEAR 1200 PRINTER IS 701 1300 DIM SAMPIDSEBOJ,SAM$[15] 1400 DIM A(200),B(200),C(200) 1500 DIM AA(200).CC(200).S(8) 1600 DISP “CALIBRATION IS MANUAL, IF YOU WANT TO MAKE ANY CHANGE" 1700 SET TIMEOUT 7310000 1800 ON TIMEOUT 7 GOTO 9200 1900 GOSUB 9900 2000 I=1 2100 CCP=0 2200 AO=704 2300 CLEAR 2400 GOSUB 25800 2500 OUTPUT AO a”K25,-30K32,3K24,2.5K31,3" 2600 OUTPUT AO ;"K21K26,0.0K27,-30.0" 2700 REM"!**PRINTER CONTROL COMMANDS #1!" 2800 DISP “Select % of Printer Scale Desire" 2900 DISP ”20 = 20%", “10 = 10%","5 = 5%" 3000 DISP "ENTER 3" 3100 INPUT NUMBER 3200 IF NUMBER=20 THEN GOTO 3600 3300 IF NUMBER=10 THEN GOTO 3800 3400 OUTPUT A0; “K13,20K15,6K19,5K20,2” 3500 SOTO 4000 3600 OUTPUT AO ; "K13,20K15,4Ki9,5K20,2" 3700 GOTO 4000 3800 OUTPUT AO; "K13,20K15,5K19,5K20,2" 3900 GOTO 4000 4000 OUTPUT AO :"K34,3" 4010 DISP "Enter Sample Identification Name (Up to 40 characters)" 4015 INPUT SAMPIDS 128 Audi-1.1.1 129 APPENDIX A. (continued) 4100 CLEAR 4105 DISP "Do you Want to Change Printer Scale“ 4200 DISP "Yes=1","No=2" 4300 INPUT 88 4310 IF BB=1 OR 88=2 THEN 4400 ELSE BEEP 400,40 4320 DISP “ENTER 1 OR 2 ONLY” e GOTO 4105 4400 CLEAR 4500 IF BB=1 THEN 2700 4600 DISP G DISP "Ready to Start" a BEEP e DISP 4700 DISP ”Enter Sample Number and Time ( Up to 10 characters)" 4800 INPUT SAMS 5000 I=1 5100 AO=704 5200 OUTPUT AO 3"K25,-30K32,3K24,2.5K31,3“ 5300 OUTPUT AO ; "K2" 5400 CLEAR 5500 OUTPUT AO ; "R2R27R3" 5600 ENTER AO ; A(I),B(I),C(I) 5700 I=I+1 5800 IF I>170 THEN GOTO 6100 5900 WAIT 397 6000 GOTO 5500 6100 OUTPUT AO ; ”K1" 6200 GOT 10300 6300 GOTO 6800 6400 DISP "YES=1", "NO=2" 6500 INPUT 88 6600 CLEAR 6700 IF 88=2 THEN GOTO 8000 6800 REM till! SAVING CONTROL PROGRAM tilt: 6900 DISP "Insert Disk to Store The Data. IthITIALIZEDtt" 7000 DISP "Enter File Name (Up to 8 characters)" 7100 INPUT FILN$ 7200 CREATE FILN$,200,50 7300 ASSIGN# 1 TO FILNS 7400 PRINT# 1 3 SAMPIDS 7450 PRINT# 1 ; SAM6 7500 FORI=1 TO 170 7600 PRINT# 1 ; A(I),8(I),C(I) 7700 NEXT I 7800 GOTO 7900 7900 ASSIGN# 1 TO I 8000 DISP "Do you want to Repeat the Test?" 8100 DISP "YES=1","NO=2" 8200 INPUT 88 8300 CLEAR 8400 IF 88=2 THEN GOTO 9100 8500 DISP ”Please WAit" 8600 FOR NN=1 TO 170 APPEN 8700 8800 8900 9000 9100 9200 9300 9400 9500 9600 9700 ‘9800 9850 9900 10000 10100 10200 10300 10400 10500 10600 10700 10800 10900 11000 11100 11200 11300 11400 11500 11600 11700 11800 11900 12000 12100 12200 12300 12400 12500 12600 12700 12800 12900 13000 13100 13200 13300 13400 DIX A. 130 (continued) A(NN),8(NN),C(NN)=0 AA(NN),CC(NN)=0 NEXT NN GOTO 4100 END FOR TT=O T0 6 STATUS 7,TT ; S(TT) PRINT "STATUS BYTE #";TT;" ="S(TT) NEXT TT PRINT “HP-18 Timeout” SOTO 9100 ! SUBRDUTINE: WAIT FOR TO BE PRESSED.. BEEP 4000,40 G DISP ”ENTER K1 KEY ONLY!" DISP "When ready, Press to Continue." ON KEY# 1 SOTO 10200 GOTO 10100 RETURN U=0 PRINTER IS 701 FOR I=1 T0 170 AAII)=ABS (A(I) @ CC(I)=ABS (C(I) NEXT CLEAR I IF CCP=1 THEN 11500 IF CCP=2 THEN 12900 DISP DISP “Do you Want The Computer To EStimate Le and Lp" IIYe5=1II ’ H No=2H INPUT CCP IF CCP=2 THEN 12900 REM tit Program to Calculate Le and Lp tittitttitt FOR I=1 TO 170 IF A(I)<-.03 THEN GOTO 11900 NEXT I R=I-2 IPV=CC(I-2) FOR I=1 TO 170 IF A(I) ON KEY# 1 GOTO 14100 GOTO 14000 CLEAR M=20 PAGESIZE 24 DISP "Force (N)","Distance (mm)","Sequential Number" FOR I=1 TO M DISP All),C(I),I NEXT I DISP "Do You Want To See More Values ?",”Yes=i";” No=2" INPUT 88 IF 88=2 THEN 16300 CLEAR IF I>160 THEN 15900 M=M+20 DISP "Force (N)","Distance (mm),"Sequential Number" FOR I=I TO M DISP A(I),C(I),I NEXT I GOTO 14800 M=M+10 CLEAR IF I=170 THEN 16300 GOTO 15400 CLEAR M=M+10 PAGESIZE 16 DISP "DO YOU WANT TO SEE THE DATA AGAIN“ DISO "YES=1", "No=2" INPUT 88 IF BB=1 THEN 14200 CLEAR DISP "Sequential Value of Initial Distance Value=?" INPUT I IPV=CC(I) R=I CLEAR DISP "Sequential Number of Break Distance ValueS?" INPUT I BFV=CC(I) PF=AA(I) LPV=CC(165) DISP "Please Wait Area CAlculations in Progress" U=U+1 APPENDIX 18300 18400 18500 18600 18700 18800 18900 19000 19100 19200 19300 19400 19500 19600 19700 19800 19900 20000 20100 20200 20300 20400 20500 20600 20700 20800 20900 21000 21100 21200 21300 21400 21500 21600 21700 21800 21900 22000 22100 22200 22300 23100 23200 23300 23400 23500 23600 23700 23800 A SUM1= FOR I SUM1= NEXT FI=(A CC(16 AREA GOSUB CLEAR DISP DISP DISP DISP DISP DISP DISP DISP DISP DISP DISP REM DISP DISP INPUT IF 88 CLEAR DISP DISP PRINT PRINT PRINT PRINT PRINT PRINT PRINT PRINT PRINT PRINT PRINT PRINT PRINT PRINT PRINT CLEAR REM DISP DISP INPUT IF 88 DISP 132 . (continued) 0 =R T0 165 SUM1+AA(I)¥(CC(I+1)-CC(I-1))*.5 I A(R-1)*(CC(R)-CC(R-1))+AA(166)3(CC(166)- 5)))#.5 (U)=SUM1+FI 25000 SAMPID$;“ ":SAM6 "Area=";AREA (U);”mm“2" "Plunger Velocity is="; 8(2);"mm/min" "Apparent Viscosity is="; VI, poise" "Apparent Elasticity is=";EA;“N/cm‘2" "Shear Rate at the PWS is=";LW;"1/sec" "Do you Want to Print These Values?" ll Yes=1 H ’ H No=2" BB =2 THEN 23200 "PRINTIING IN PROGRESS, PLEASE WAIT" C DISP "PRINTING IN PROGRESS, PLEASE WAIT“ "*ttltilitttt3*lititlttlilttlitttitttt" SAMPID$; "35AMS "Area=";AREA (U);"mm“2" "Plunger velocity is =";8(2);"mm/min" "Apparent Viscosity is="VI;"poise" "Apparent Elasticity is=";EA;"N/cm“2" "Shear Rate at the PWS is=";LW;"1/sec" "Do You Want to Print the Raw Data?” "YESgl u ’ 00N0=2u BB =2 THEN 24700 "PRINTING IN PROGRESS,PLEASE WAIT" APPENDIX 23900 24000 24100 24200 24300 24400 24500 24600 24700 24800 24900 25000 25100 25200 25300 25400 25500 25600 25700 25800 25900 26000 26100 26200 26300 26400 26500 26600 26700 26800 26900 27000 27010 27020 27100 27200 27300 27400 27500 27600 27700 27800 27900 28000 28100 '28200 28300 28400 28500 28600 133 A. (continued) PRINT"tittittttxtttitittxtttxttttttt" PRINT PRINT SAMPIDS PRINT PRINT “Force (N)","Distance (mm)","Sequential Number" FOR I=1 TO 170 PRINT A(I),C(I),I NEXT I CLEAR GOTO 6300 END CLEAR DISP "Please Wait Viscosity Calculations in Progress” REM *tBASIC CALCULATIONStttt LP=LPV—IPV LE=BFV—IPV F=2XAREA(U)/LP VP=B(2) GOTO 28400 REM IIVISCOSITY INDEX VP=20 RI=4.255 RO=7.028 DISP "The Viscosity Constants Used Are:" DISP DISP DISP DISP DISP DISP "DO YOU WANT TO CHANGE THE VISCOSITY CONSTANTS ?" DISP "YES=1","NO=2" INPUT 88 IF BB=1 OR BB=2 THEN 27100 ELSE BEEP 400,40 DISP ”ENTER ONLY A 1 OR 2 " G GOTO 26800 IF BB=2 THEN GOTO 28300 CLEAR DISP "VALUE OF PLUNGER VELOCITY IS=?“ INPUT VP CLEAR DISP “PLUNGER RADIUS, INPUT RI CLEAR DISP ”INNER TEST TUBE RADIUS, INPUT RO CLEAR RETURN RETURN DISP ”PLEASE WAIT ELASTICITY CALCULATIONS IN PROGRESS" REM tiltApparent VIscosity Calculations xttttttt K=RI/RO CALCULATIONS****X* "-Plunger Velocity = 20 mm/min" "-Plunger Radius = 4.255 mm“ "-Inner Test Tube Radius 8 7.028mm" IN mm, IS=?" IN mm,IS=?" 134 APPENDIX A. (continued) 28700 ALFA=(1-K‘2)/(1+K“2) 28800 VI=1/(2!PI!VP)!(F/LP)!(1-K“2)!LOG(1/K)!(1+ALFA/LOG(K)) !6!10“8 28900 REM!!APPARENT ELASTICITY CALCULATIONS!!! 29000 SIGMA=SOR ((RO-RI)“2+LE‘2) 29100 ROA=PF/(PI!(RI“2+SIBHA!(RI+RO)I) 29200 EP=(RI+SIGMA-RO)/RO 29300 EA=ROA/EP!100 29400 REM !!!SHEAR RATE AT THE PWS!!!! 29500 LN=((’(ALFA/(LOG(K)+ALFA)I)!(VP/RI))/6O 29600 RETURN 29700 END APPENDIX B. List of computer program Delia. 1000 1050 1100 1150 1200 1250 1300 1350 1400 1450 1500 1550 1600 1650 1700 1750 1800 1850 1900 1950 2000 2050 2100 2150 2200 2250 2300 2350 2400 2450 2500 2550 2600 2650 2700 2750 2800 2850 2900 2950 3000 3050 3100 3150 3200 3250 DISP @ DISP e DISP DISP " !!! PROGRAM DELIA BY CARLOS A. LEVER !!! " L DISP DISP “t! THIS PROGRAM USES DATA FROM INSTROM CONTROL PROGRAM RODRIGO xx" DISP ”TO CALCULATE APPARENT VISCOSITY AND APPARENT ELASTICITY," DISP " FROM BACKEXTRUSION DATA " REM DISP e WAIT 5000 e CLEAR u=o CCP=0 PRINTER IS 701 DIM A(200),B(200),C(200),AA(200),CC(200) DIM AREA(10) DIM SAMPID$E853 DISP GOSUB 10000 DISP "ENTER FILE NAME WITH INSTROM RAW DATA” INPUT FILNAMEs ASSIGN# 1 TO FILNAMES . READ# 1 3 SAMPIDs , DISP SAMPIDs DISP FOR I=o TO 170 READ# 1 ; A(I),B(I),C(I) AA(I)=ABS(A(I)) e CC(I)=AGS(C(I)) NEXT I IF CCP=1 THEN 2600 IF CCP=2 THEN 3950 CLEAR DISP "DO YOU WANT THE COMPUTER TO ESTIMATE Le AND Lp" DISP ”YES=1","NO=2" INPUT CCP REM !! PROGRAM TO CALCULATE Le AND Lp DISTANCE xx IF CCP=2 THEN 3950 FOR I=I TO 165 IF A(I)<-.03 THEN GOTO 2850 NEXT I IPV=CC(I-1) R=I-2 FOR I=I TO 165 IF A(I) 3850 ON KEY# 1 GOTO 3950 3900 GOTO 3900 3950 CLEAR 4000 M=20 4050 PAGESIZE 24 4100 DISP "Force (N)","Distance (mm)”,"Sequential Number" 4050 FOR I=1 TO M 4200 DISP A(I),C(I),I 4250 NEXT I 4300 DISP "Do You Want To See More Values 7",”Yes=1“;" No=2" 4350 INPUT BB ' 4400 IF BB=2 THEN 5300 4450 CLEAR 4500 IF I>160 THEN 4850 4550 M=M+20 4600 DISP "Force (N)","Distance (mm),”Sequential Number“ 4650 FOR I=I TO M 4700 DISP All),C(I),I 4750 NEXT I 4800 GOTO 4300 4850 CLEAR 4900 M=M+10 4950 IF I=170 THEN 5100 5000 GOTO 4600 5050 PAGESIZE 16 5100 DISP "DO YOU WANT TO SEE THE DATA AGAIN" 5150 DISO "YES=1", "No=2" 5200 INPUT BB 5250 IF BB=1 THEN 3350 5300 CLEAR 5350 PAGESIZE 16 5400 DISP ”INPUT INITIAL DISTANCE AND BREAK DISTANCE NUMBER" 5450 INPUT I,J 5500 IPV=CC(I) 5550 R=I 5600 BFV=CC(J) 5650 PF=AA(J) 5700 LPV=CC(165) APPENDIX 5750 5800 5850 5900 5950 6000 6050 6100 6150 6200 6250 6300 6350 6400 6450 6500 6550 6600 6650 6700 6750 6800 6850 6900 6950 7000 7050 7100 7150 7200 7250 7300 7350 7400 7450 7500 7550 7600 7650 7700 7750 7800 7850 7900 7950 8300 8350 8400 8450 CLEAR 137 B. (continued) DISP "Please Wait Area CAlculations in Progress” U=U+1 SUM1=0 FOR I =2 TO 165 SUM1=SUM1+AA(I)!(CC(I+1)-CC(I-1))!.5 NEXT FI=(A (CC(1 I All)!(CC(2)-CC(1))+AA(166)!(CC(166)- 65)))!.5 AREA(U)=SUM1+FI GOSUB CLEAR DISP DISP DISP DISP DISP DISP DISP DISP DISP DISP DISP REM GOTO DISP DISP INPUT IF BB DISP DISP PRINT PRINT PRINT PRINT PRINT PRINT PRINT PRINT PRINT PRINT PRINT PRINT PRINT PRINT PRINT CLEAR GOTO DISP DISP 9600 SAMPID$;" ":SAMs "Area=";AREA (U);"mm“2" "Plunger Velocity is="; B(2);"mm/min" "Apparent Viscosity is="; VI;"poise" "Apparent Elasticity is=";EA;"N/cm“2" "Shear Rate at the PWS is=";LW;"i/sec" 7200 "Do you Want to Print These Values?“ IO Yes=1 ll ’ OI No=2" BB =2 THEN 8300 "PRINTIING IN PROGRESS, PLEASE WAIT" “PRINTING IN PROGRESS, PLEASE WAIT" “u DISP ”!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!" SAMPIDS; " ":SAMs "Area=";AREA (U);"mm“2" "Plunger velocity is =”;8(2);"mm/min" “Apparent Viscosity is="VI;"poise" ”Apparent Elasticity is=";EA;"N/cm“2" "Shear Rate at the PWS is=”;LW;"1/sec" 9350 "Do You Want to Print the Raw Data?" .0 YES=1 II ’ OI N082" APPEN 8500 8550 8600 8650 8700 8750 8800 8850 8900 8950 9000 9050 9100 9150 9200 9250 9300 9350 9400 9450 9500 9550 9650 9700 9750 9800 9850 9900 9950 10000 10050 10100 10150 10200 10250 10300 10350 10400 10450 10500 10550 10600 10620 10730 10650 10700 10750 10780 10800 138 DIX 8. (continued) INPUT 88 IF BB=2 THEN 9100 DISP "PRINTING IN PROGRESS,PLEASE WAIT” PRINT"!!#!*!!!!!!!!it!!!t!!!!!!!!t!!!!!!!!!!!t" PRINT PRINT SAMPIDS PRINT PRINT "Force (N)","Distance (mm)","Sequential Number" FOR I=1 TO 165 PRINT A(I),C(I),I NEXT I GOTO 9100 CLEAR DISP "DO YOU WANT TO READ ANOTHER FILE ?" DISP "1=YES","2=NO" INPUT SINO IF SINO=2 THEN 9550 FOR L=1 TO 165 A(L),B(L),C(L),AA(L),CC(L)=O NEXT L GOTO 1800 END DISP "Please Wait Viscosity Calculations in Progress" REM !!BASIC CALCULATIONS!!!! ' LP=LPV-IPV LE=BFV-IPV F=2¥AREA(U)/LP VP=B(2) GOTO 11150 REM ##VISCOSITY INDEX CALCULATIONS!!!!!! VP=20 RI=4.255 RO=7.028 DISP "The Viscosity Constants Used Are:” DISP DISP "CONTANT (1)-Plunger Velocity = 20 mm/min" DISP "CONTANT (2)-Plunger Radius = 4.255 mm" DISP "CONSTANT(3)-Inner Test Tube Radius = 7.028mm" DISP DISP "IF YOU WANT TO CHANGE ANY OF THEM, INPUT CONSTANT NUMBER " DISP "IF NOT THEN INPUT 0" INPUT BBGCLEAR'GIF BB=O THEN RETURN IF BB=1 OR BB=2 OR B=3 THEN 10650 ELSE BEEP 400,40 DISP "ENTER ONLY A 1, 2 OR 3 " e GOTO 10500 IF BB=1 THEN GOTO 10800 IF BB=3 THEN 11000 IF BB=2 THEN 10900 CLEAR DISP "ACTUAL PLUNGER VELOCITY IS=";VP;mm/min, INPUT .7. 1.2%.“; lit... at, . 139 APPENDIX 8. (continued) NEW VALUE" 10850 INPUT VP G CLEAR 9 GOTO 1200 10900 DISP "ACTUAL PLUNGER RADIUS, IS";RI;"mm, INPUT NEW VALUE“ 10950 INPUT RI 0 CLEAR e GOTO 10200 11000 DISP “ACTUAL INNER TEST TUBE RADIUS IS";RO;"mm, INPUT NEW VALUE" 4 11050 INPUT RO @ CLEAR @ GOTO 10200 11100 RETURN 11150 DISP . 11200 DISP "PLEASE WAIT ELASTICITY CALCULATIONS IN PROGRESS" A 11250 REM !!!!Apparent VIscosity Calculations !!!!!!!! . 11300 K=RI/RO ' 11350 ALFA=(1-K“2)/(1+K“2) 11400 VI=1/(2!PI!VP)!(F/LP)!(1-K“2)!LOG(1/K)!(1+ALFA/LOG(K)) !6!10“8 11450 REM!!APPARENT ELASTICITY CALCULATIONS!!! 11500 SIGMA=SOR ((RO-RI)‘2+LE“2) 11550 ROA=PF/(PI!(RI“2+SIGMA!(RI+RO))) 11600 EP=(RI+SIGMA-RO)/RO 11650 EA=ROA/EP!100 11700 REM !!!SHEAR RATE AT THE PWS!!!! 11750 LW=((~(ALFA/(LOG(K)+ALFA)))!(VP/RI))/60 11800 RETURN ' 11850 END APPENDIX C. List of computer program Mariana. 1000 1050 1100 1150 1200 1250 1300 1350 1400 1450 1500 1550 1600 1650 1700 1750 1800 1850 1900 1950 2000 2050 2100 2150 2200 2250 2300 2350 2400 2450 2500 2550 2600 2650 2700 2750 2800 2850 2900 2950 3000 CLEAR @ DISP G DISP DISP "!!! PROGRAM MARIANA BY CARLOS A. LEVER !!!!!" REM !!!! DISP DISP ”!! PROGRAM TO CALCULATE THERMAL MODEL VARIABLES !!!!!!!!!" U=0 DIM tt(60), Ta(60), TT(15,65), Tt(15,65) DIM t(100), Y(100), T(100), X(100) DIM n(100), c(5,65), a(5,65), FO(80), TRA(60), RMU(30). Fo(80) DIM FLN$[8], SID$E80], TFLNSElO] CCP=0 DIM PSIA (15,65), PSIAV(65), A_PRIME(15,65) PRINTER IS 701 DISP REM !!!!!! MODEL CALCULATION ROUTINES !!!!!!!!!!!!!!!! REM DISP DISP " If you Want to Calculate the Thermal Process (Bi, Fo,etc.), TYPE 1 DISP . DISP " If you Want to Calculate A' and alpha, TYPE 2" DISP DISP "If you Want to Calculate First Raw Estimate of Ea, TYPE 3“ DISP DISP "If you Want to Calculate a(kt), TYPE 4" DISP DISP "If you Want to Calculate TTH, TYPE 5" DISP DISP “If you Want to Calculate Rings Temperature, TYPE 6“ INPUT BB CLEAR IF IF IF IF IF IF BB=1 BB=2 BB=3 BB=4 BB=6 BB=5 THEN THEN THEN THEN THEN THEN 2850 20000 21450 23100 10950 15300 ELSE BEEP 9 CLEAR 8 DISP "WRONG CHOICE " G GOTO 1700 CLEAR !!!!!!! Calculation of Thermal Process !!!!!!!!!!! K=1 G D=2 DISP " Will Data Be Input From Keyboard (k) or from Disk (D)" DISP “Input k OR d" 0 INPUT BB REM 140 APPENDIX 3050 3100 3150 3200 3250 3300 3350 3400 3450 3500 3550 3600 3650 3700 3750 3800 3850 3900 3950 4000 4050 4100 4150 4200 4250 4300 4350 4400 4450 4500 4550 4600 4650 4700 4750 4800 4850 4900 4950 5000 5050 5100 5150 5200 5250 5300 141 C. (continued) IF BB=1 THEN 3700 IF BB=2 THEN 3150 ELSE CLEAR e GOTO 2950 CLEAR DISP "Enter File Name" INPUT FLNS ASSIGN# 1 TO FLNs READ # 1 ; SID$ DISP SIDs @ DISP FOR x=1 TO 30 READ# 1 ; tt(x), T(x) IF T(x)=0 then 3650 NEXT X ASSIGN# 1 TO ! G GOTO 4750 DISP "INPUT TIME (sec) and Temperature (C)" DISP "INPUT 0.0 when finish" FOR x=1 TO 100 DISP "sample No." ; x INPUT TT(x), t(x) IF T(x)=0 THEN 4050 NEXT x CLEAR e DISP " Storage of Data is Next" G DISP DISP " Insert Disk to Store Data (!! Initialized Disk !!)" DISP "Enter File Name (up to eight Characters)" INPUT FLN$ . CREATE FLNS, 15,100 ASSIGN# 1 TO FLNs DISP "Enter Sample Identification (up to 40 Characters)" INPUT SIDS PRINT” 1 ; SIDS FOR PP=1 TO x PRINT# 1 ; tt(PP), NEXT PP ASSIGN4 1 TO ! DISP "time", "Temperature" Print "time”, "Temperature" DISP 0 FOR PP=1 TO x-i C DISP tt(PP), tt(PP), T(PP) NEXT PP REM !!!! Calculation of F0, [T], Bi, r/r !!!!!!!!!!!! REM !!! Constants use in F0 and [TI are Defined Next!!!! Ti=20 Cp= 3.9216375 DEN= 1071.823 MOI= 90 Tin= 7O REM !!!!! FO CALCULATION!!!!!!!!!! CLEAR T(PP) T(PP) Q PRINT APPENDIX 5350 5400 5450 5500 5550 5600 5650 5700 5750 5800 5850 5900 5950 6000 6050 6100 6150 6200 6250 6300 6350 6400 6450 6500 6550 6600 6650 6700 6750 6800 6850 6900 6950 7000 7050 7100 7150 7200 7250 7300 7350 7400 7450 7500 7550 7600 7650 142 C. (continued) DISP “F0 AND [T] CONSTANTS ARE:" DISP DISP DISP Cp="; cp; "Kj/Kg-K" Density (RO)="; DEN; "Kg/mc3" Initial Temperature of Sample "Constant (1) ; "Constant (2) ; DISP "Constant (3) ; (To)="; Ti; “C" DISP "Constant (4) Temp, of Water Bath=; Tin; "C" DISP a DISP "Do you Want to Change any of Them?" I DISP "If YES then input Constant No." ‘ DISP "If NO then input 0" INPUT 88 IF BB=0 THEN 7000 IF BB=2 THEN 6800 IF BB=3 THEN 6400 IF BB=4 THEN 6600 CLEAR DISP “To Calculate New Cp, Sample" DISP "as PERCENTAGE INPUT MOI Cp=1.675+.025!MOI GOTO 5300 . CLEAR 2 DISP "Input New Value of To (C)" INPUT Ti GOTO 5300 CLEAR DISP ”Input New Value of T (water bath- C)" INPUT Tin GOTO 5300 CLEAR DISP "Input New Value for Density (RO). INPUT DEN GOTO 5300 REM !!!! FO FROMULA !!!! RAR= 7.028/1000 ! r from mm to meters RR=RAR!RAR ! r02 TOL=1!10“-5 ! For use in MAXI=35 E IDEM than TOL REM DISP "Please Wait , FOR X=1 TO x-i ThC= (.30776.775!10“-4!T(X)!.001730314961 ! Kj-m/sec-mAZ-C THC=ThCl (DEN!Cp!RR) FO(X)= tt (X)! THC TRA (X)= (Tin-T(X)))/(Tin-Ti) REM !!!! printing option for Checking values!!!!!! REM !!! ' Input Moisture Content of (O to 100)" in Kg/m93" Bessel and Bissect Subr. F0 and [t] calculations are next" to get 143 APPENDIX C. (continued) 7700 7750 7800 7850 7900 7950 8000 8150 8200 8250 8300 8350 8400 8450 8500 8550 8600 8650 8700 8750 8800 8850 8900 8950 9000 9050 9100 9150 9200 9250 9300 9350 9400 9450 9500 9550 9600 9650 9700 9750 9800 9850 9900 9950 DISP FO(X), TRA(X), tt (X) PRINT USING "3A,ZD,2A,D.4D,X,5A,ZD,2A,D.4D, X,3D,X,4A"; "FO(”,X,")=”,FO(X),TETA (",X,")=”,TRA(X),tt (X),"sec." NEXT X CLEAR REM !!!! CALCULATIONS FOR BI!!!!!!!!!!! CLEAR L“ DISP "Calculations for Bi are next" FOR X=1 TO x-1 I FOU=FO(X) . TETA=TRA(X) “=1 l XB=5 FA=FNFUN (XA) FB=FNFUN (XB) JJJ=1 GOSUB BISECT RMU (X)=RD @ IF RMU (X)=5 THEN 8650 ELSE 8750 DISP “Value of Sample No (";X;") is out of Range" DISP "Then a Very High Value of Bi (2!10“40) will be assumed" RD=0 NEXT X . WAIT 5000 . CLEAR PAGESIZE 24 CLEAR DISP "All values of Bi (Experimental) are Displayed” DISP "Select Range to be Considered (First and Last SEQUENTIAL Values)" DISP DISP DISP "Bi “, ”Sequential Number" PRINT G PRINT 9 PRINT FOR X-i TO x-i LBi= .08359!RMU(X)“4.35842959 Bi=EXP (LBi) DISP Bi, X PRINT "Bi (";X;")=”Bi NEXT X DISP G DISP G DISP "Press 1 to Continue" INPUT BB PAGESIZE 16 CLEAR ’ DISP "Input First and Last Value of Bi Selected (Sequential Value)" INPUT FIRST, LAST RMUA=0 10000 FOR X=FIRST TO LAST 10050 RMUA=RMUA+RMU (X) APPENDIX C. 10100 10150 10200 10250 10300 10350 10400 10450 10500 10550 10600 10650 10700 10750 10800 10850 10900 10950 11000 11050 11100 11150 11200 11250 11300 11350 11400 11450 11500 11550 11600 11650 11700 11750 11800 11850 11900 11950 12000 12050 12100 12150 144 (continued) NEXT X RMUAa=RMUAl(LAST+1-FIRST) TEM LBi = .08359!RMUAa“4.35843 CLEAR CLEAR DISP "average Bi="; Bi DISP "Values Utilized Were From "; FIRST;" to "; LAST @ PRINT @ PRINT PRINT PRINT "Average Bi="Bi,"Average MU=";RMUAa, “Average M=”;1/8i PRINT "Values Utilized Were From"; FIRST; " to "; LAST 8 PRINT @ PRINT MUA=RMUAa FOR X=1 TO x-i RMU (X) =0 NEXT X DISP GOTO 11450 REM !!!! Calculations for r/R !!!!!!!!!!!!!!! DISP ”Calculations for r/R and [T15 are Next" DISP G DISP Cp=3.9216375 G DEN+ 1071.823 0 MAXU=35 RAR= 7.028/1000 ! r from mm to meters RR=RAR!RAR ! r92 Bi= 15.724 G Ti=20 e disp "Bi=";Bi, "Temp. Initial=";Ti . DISP "Input Temp of Water Bath “ 0 INPUT Tin ThC=(.3077 + 6.775! 109-4 ! Tin)! .001730314961 THC= ThC/(DEN!Cp!RR) AREA=155.1720074 @ TOL= 1!10“-5 IRADI= 7.028 NA=1O G TOLE= .01 G Ea= 20000 CLEAR 9 DISP e DISP "Value Of Ea ="; Ea DISP "Number of Rings to be considered is";NA e DISP e GOTO 12150 DISP "If you Want to change any of them TYPE Ea or NR" DISP "To continue TYPE C” INPUT 8860 IF 886=”Ea" THEN 12000 IF BB$= "NR" THEN 12050 IF BB$= “C" THEN 12150 ELSE 11950 BEEP 8 BEEP e DISP "Wrong Choice,try Again" 8 Wait 2000 e GOTO 11600 DISP "INPUT NEW VALUE OF Ea (Cal)“@INPUT EaG GOTO 11600 DISP "INPUT NEW VALUE OF NUMBER OF RINGS” e INPUT NA 0 GOTO 11600 Ea=2000 DISP 145 APPENDIX C. (continued) 12200 DISP "STORAGE OF t(I,J) Data Parameters are Next" 12300 DISP “ENTER FILE NAME ( UP TO 8 CHARACTERS)" 12350 INPUT TFLNs 12400 DISP " Please wait,intense calculations in progress" 12450 DISP G DISP " Calculation of MU roots (6) is next" 12500 XA= .1 12550 XB= 18 12600 JJJ=2 G X=1 12650 GOSUB BISECT2 12700 LL=1 G BEEP G DISP "The 6 MU's roots calculated" 12750 FOR OO=1 TO 6 G PRINT "R(";OO;")=";R(OO)@ NEXT 00 12800 RMU(LL)=R(LL) 12850 DISP @ DISP “Calculation of NODE temperatures are next" 12900 FOR TIEMPO =0 TO 1800 STEP 30 12950 SUMl = 0 13000 X= TIEMPO/30 +1 13050 Fo(X)= THC!TIEMPO 13100 FOR Ii =0 TO NA 13150 ENE=SOR(Ii/NA) 13200 FOMU12=Fo(X)!RMU(LL)“2 13250 ROO=RMU(LL)!ENE 13300 VRMU=RMU(LL) - 13350 VFF=FNANJO(VRMU,ROO) ‘ 13400 SUM1=SUM1+VFF 13450 DISP @ DISP "!! Calculation Round, Time"; TIEMPO;"SEC RING";Ii;",ROOT";LL 13500 LL=LL+1 @ IF LL>6 THEN 13700 13550 RMU(LL)=R(LL) 13600 FOMU12=Fo(X)!RMU(LL)‘2 13650 GOTO 13250 13700 TETA=SUM1 13750 TT(Ii,X)=TETA!(Ti—Tin)+Tin 13800 BEEP @ DISP 13850 DISP " !! TEMP AT RING";Ii;"AND TIME";TIEMPO;"SEC, =”;TT(Ii,X);"!!" 13900 IF TT(°,X)>=Tin-TOLE THEN 14150 13950 ll=1 G SUM1=0 14000 NEXT Ti 14050 NEXT TIEMPO 14100 CLEAR G GOTO 14450 14150 FOR RE=X TO 61 14200 FOR IE=O TO NA 14250 TT(IE,RE)=Tin 14300 NEXT IE 14350 NEXT RE 14400 PRINT SIDS 14450 PRINT USING "5A,11(X,5A)";"SEC","RO","R-i","R-2",” R_3H ’ DIR-4H ’ CIR—.5" ’ DIR-6H ’ DIR-7” ’ IOR-ell ’ OUR-9M ’ OUR-1°" 14500 FOR J=1 TO 61 APPENDIX 14550 14600 14650 14700 14750 14800 14850 14900 14950 15000 15050 15100 15150 15200 15250 15300 15350 15400 15450 15500 15550 15600 15650 15700 15750 15800 15850 15900 15950 16000 16050 16100 16150 16200 16250 16300 16350 16400 16450 16500 16550 16600 16650 16700 146 C. (continued) PRINT USING "5D,11(X,2D.20)”;J!30-30,TT(0,J),TT(1,J), TT(2,J),TT(3,J),TT(4,J),TT(5,J),TT(6,J),TT(7,J), TT(8,J), TT(9,J),TT(10,J) DISP USING "50,11(X.2D.20)";J!30-30,TT(0,J),TT(1,J). TT(2,J),TT(3,J),TT(4.J).TT(6.J).TT(6.J).TT(7.J). TT(8,J), TT(9,J),TT(10.J) NEXT J .4 CLEAR @ DISP "STORAGE OF T(i,j) DATA IS NEXT " e DISP CREATE TFLNs, 11.500 ASSIGN# 1 TO TFLNs PRINT# 1;SID$ FOR E=1 TO 61 FOR N=o TO NA PRINTa 1;TT(N,E) NEXT N NEXT E ASSIGN# 1 TO I DISP "TTH CALCULATIONS ARE NEXT" DISP REM xx CALCULATIONS FOR TTH !! DISP "TTH CALCULATIONS ARE NEXT" Ea = 20000 DISP @ DISP " VALUE OF Ea Ea DISP " IF YOU WANT TO CHANGE IT TYPE Ea" DISP " TO CONTINUE TYPE C" INPUT BBS e IF aas= "Ea" then 15750 IF 886 = "C” THEN 15850 ELSE 15700 BEEP @ BEEP G DISP " WRONG CHOICE, TRY AGAIN"e WAIT 2000 a GOTO 15450 DISP " INPUT NEW VALUE OF Ea " @ INPUT Ea e GOTO 15450 CLEAR @ DISP "DATA WILL BE INPUT FROM DISK (D) OR KEYBOARD (K)" DISP INPUT ass IF BBs="D" IF BB$=”K" CLEAR DISP "ENTER FILE NAME" INPUT FLNs ASSIGN» 1 TO FLN$ READ» 1; SIDS DISP SIDs e DISP FOR E=1 TO 61 FOR NA=0 TO 10 READ» 1; TT(NA,E) NEXT NA NEXT E ASSIGN# 1 TO 3 e GOTO 17850 DISP ”INPUT NUMBER OF RINGS CONSIDERED" INPUT NA e CLEAR @ DISP G GOTO 18150 THEN 16050 THEN 17850 ELSE BEEP Q GOTO 15300 APPENDIX 16750 16800 16850 16900 16950 17000 17050 17100 17150 17200 17250 17300 17350 17400 17450 17500 17550 17600 17650 17700 17750 17800 17850 17900 17950 18000 18050 18100 18150 18200 18250 18300 18350 18400 18450 18500 18550 18600 18650 18700 18750 18800 18850 -TT(8,J), 147 C. (continued) DISP ”INPUT NUMBER OF SAMPLES PER RING" INPUT J G CLEAR FOR X=1 TO NA FOR RR=1 TO J DISP " INPUT TEMPERATURE (RING,TIME) OF SAMPLE (II;X;H’H;RR;H)II INPUT TT(X,RR) NEXT RR NEXT X CLEAR G DISP " STORAGE OF DATA IS NEXT " G DISP DISP "INSERT DISK TO STORE DATA (!! INITIALIZED DISK!!)" DISP " ENTER FILE NAME (UP TO EIGHT CHARACTERS)" INPUT TFLN$ CREATE TFLN$,11,600 DISP "ENTER SAMPLE IDENTIFICACTION (UP TO 50 CHARACTERS)” INPUT SID$ PRINT# 1 ; SIDs FOR RR=1 TO J FOR NA=0 TO X NEXT NA NEXT RR . ASSIGN» 1 TP x . CLEAR BB=0 G T=0 G R=1.986 G I=0 G DT=30 G PSI=0 G PEPE=O PRINT G PRINT G PRINT SIDs FOR J=1 TO 61 DISP USING "5D,11(X,2D.2D)" ; J!30-30,TT(O,J),TT(1,J), TT(2,J),TT(3,J),TT(4,J),TT(5,J),TT(6,J),TT(7,J), TT(9,J),TT(10,J) PRINT USING "5D.11(X,20.2D)" ;J!30-30,TT(O,J),TT(1,J). TT(2,J),TT(3,J),TT(4,J),TT(5,J),TT(6,J),TT(7,J), TT(8,J), TT(9,J),TT(10,J) NEXT J DISP " PLEASE WAIT, INTENSE CALCULATIONS IN PROGRESS" BB=0 G T=0 G R=1.986 G I=O G DT=30 G PSI=0 G PEPE=0 PRINT G PRINT G PRINT SIDs DISP G DISP "TRANSFORMATION FORM C TO K IN PROGRESS" FOR J=1 TO 61 FOR I=0 TO 10 Tt=TT(I,J)+273.2 IF Tt<313.2 then 18550 else 18600 A_PRIME(I,J)=0 G GOTO 18650 A_PRIME(I,J)=Tt!EXP (-(Ea/R!Tt))) NEXT I NEXT J DISP G DISP “CALCULATION OF A‘ FOR I=O TO 10 FOR J=2 TO 61 p1 IN PROGRESS" 148 APPENDIX C. (continued) 18900 18950 19000 19050 19100 19150 19200 19250 19300 19350 19400 19450 19500 19550 19600 19650 19700 19750 19800 19850 19900 19950 20000 20050 20100 20150 20200 20250 20300 20350 20400 20450 20500 20550 20600 20750 20800 20850 20900 20950 21000 21050 21100 21150 21200 21250 21300 21350 PSI=(A_PRIME(I.J)+A_PRIME(I,J))lszT PEPE=PEPE+PSI PSIA(I,J)=PEPE NEXT J PEPE=0 @ PSI=0 NEXT I DISP G DISP ”TTH CLACULATIONS FOR EACH RING ARE IN PROGRESS" PSI=0 FOR J=2 TO 61 FOR I=0 TO 10 PSI=PSIA(I,J)+PSI NEXT I PSIAV(J)=PSI/10 PSI=0 NEXT J DISP "TTH AVERAGE" FOR J=2 TO 61 DISP "TTH AT " ;J!30-30; "SEC = ";PSIAV(J) PRINT ”TTH AT " ;J!30-30; "SEC a ";PSIAV(J) NEXT J CLEAR GOTO 1700 . REM xxx ESTIMATION OF A' AND ALPHA xxxx REM SX,SY,SXY,SXX,SYY=0 FOR X=1 TO 20 DISP "INPUT Y' AT N (INFINITE) AND PROTEIN CONCENTRATION (DRY BASIS) NO" ; x DISP "INPUT 0,0 WHEN FINISH” INPUT Y,C IF Y=o THEN 20550 YY(X)=LGT (Y) XX(X)=LGT (C) GOTO 20800 GOSUB LINREG DISP "A'=" ;10“a,”alpha=",b,";R“2=";r!r,"n=";x-1 GOTO 1700 REM xxxxx LINEAR REGRESSION SUBROUTINE xxxxx SX(SX+XX(X) SYY=SYY+YY(X)!YY(X) SY=SY+YY(X) SXY=SXY+YY(X)!XX(X) SXX=SXX+XX(X)!XX(X) CLEAR NEXT X LINREG: b=(-((X-1)xSXY)+SxxSY)/(-((X—1)xSXX)+sxxSX) a=(SX!SXY-SXX!SY)/(SX!SX-(X-I)!SXX) r-((X-1)!SXY-SX!SY)/SOR (((X—1)xSXX-sxxSX)x((x-I) 149 APPENDIX C. (continued) 21400 21450 21500 21550 21600 21650 21700 21750 21800 21850 21900 21950 22000 22050 22100 22150 22200 22250 22300 22350 22400 22450 22500 22550 22600 22650 22700 22750 22800 22850 22900 22950 23000 23050 23100 23150 23200 23250 23300 23350 23400 23450 23500 23550 23600 23650 23700 !SYY -SY!SY)) RETURN REM !!!!!! ESTIMATION OF Ea !!! !!!!!!!!!!!!!!!!! T,t,Y=0 SX,SY,SXY,SXX,SYY=O FOR x=1 TO 10 FOR X=1 TO 100 DISP " INPUT TEMPERATURE (IN C) AND TIME (SEC) FOR EXP. NO. " ; X DISP "ESTIMATION OF Ea No. ";x DISP "WHEN FINISH INPUT 0,0" INPUT T,t IF T=0 THEN 22150 XX(X)=1/(t+273.2) YY(X)=LGT (t) CLEAR GOTO 20850 GOSUB LINREG r(x)=r Ea(x)=b!1.986 DISP "Ea=";Ea(x),"R=;r(x),"VARIABLE No ”;x PRINT "Ea=";Ea(x),“R=;r(x),"VARIABLE No ";x DISP "DO YOU WANT TO CALCULATE ANOTHER Ea" DISP "YES=1", "No=2" INPUT 88 IF 88=2 THEN 22650 NEXT x EA=O FOR X=1 TO x EA=EA+Ea(X) NEXT X Ed=EA/x DISP "Ea AVERAGE OF“;x;"EXPERIMENTS IS =";Ed;”CAL/MOL" PRINT " Ea AVERAGE IS =“;Ed;"CAL/MOL" CLEAR GOTO 1700 REM !! SUBROUTINE TO ESTIMATE (a) !! DISP DISP "CALCULATION OF (a) WILL BE THE AVERAGE OF 3 SETS OF VALUES" FOR m=1 TO 3 b=1 a=0 DISP "INPUT VALUES OF Y'(a),PSI(a), AND Y'(b),PSI(b)" DISP “OF SAMPLE "' m INPUT y(1). psia(1),Y(2),psia(2) CLEAR DISP "PLEASE WAIT INTENSE CALCULATIONS IN PROGRESS" DISP "round";m LHS=y(1)/y(2) I'M. 150 fiat-1"“. - r—T APPENDIX C. (continued) 23750 FOR X=1 TO 10 23800 FOR x=1 TO 100 23850 c=a+b!x 23900 RHS=(1-EXP (-(c!psia(1))))/(1-EXP (-(C!psia(2)))) 23950 IF RHS>LHS THEN 24050 24000 NEXT x 24050 a=c+(x-1_!b 24100 b=b!.1 24150 NEXT X 24200 A(m)=a 24250 DISP ”a(";m;")=";A(m) 24300 NEXT m 24350 AV=(A(1)+A(2)+A(3))/3 24400 DISP "(a) AVERAGE IS ="; AV 24450 PRINT 24500 PRINT "(a) AVERAGE IS =”; AV 24550 PRINT 24600 PRINT "a(i)="; A(i),”a(2)=";A(2),"a(3)=";A(3) 24650 PRINT 24700 CLEAR 24750 GOTO 1700 24800 REM !!! SUBROUTINE DEFINITION OF BESSEL FUNCTION !!!! 24850 DEF FNBESJ (ROO) 24900 24950 25000 25050 25100 25150 25200 25250 25300 25350 25400 25450 25500 25550 25600 25650 25700 25750 25800 25850 25900 25950 26000 26050 26100 26150 TOL=1!10“-5 G DISP G DISP “CALCULATION OF BESSEL FUNCTION, SAMPLE No.”;X X2=ROO!ROO FNBESJ=0 IF ROO>15 THEN 25600 SUM=1 TERM2=SUM I=0 I=I+1 TERM+TERM2 TERM2=-(TERM!X2!.25/(I!I)) SUM=SUM+TERM2 IF ABS (TERM2)>ABSD (SUMxTOL) THEN 25250 FNBESJ=SUM GOTO 25650 FNBESJ=SOR (2/(PIxROO))xCOS (ROO-PI /4) FN END END REM xxxxxx DEFINITION OF FUNCTION FNFUN (RMU) xxxxxxx DEF FNFUN (RMU) RM=RMU ATE=LOG (TETA) FNFUN=RM!RM!FOU-.5395!LOG (RM)+ATE-.O3974 FN END END REM xxx SUBROUTINE BISECT xxxxxxxxxxxxxxxxx REM APPENDIX C. (continued) 26200 26250 26300 26350 26400 26450 26500 26550 26600 26650 26700 26750 26800 25850 26900 26950 27000 27100 27150 27200 27250 27300 27350 27400 27450 27500 27550 27600 27650 27700 27750 27800 27850 27900 27950 28000 28050 28100 28150 28200 28250 28300 28350 28400 28450 28500 28550 28600 28650 BISECT: RM=O G RD=0 G DISP "CALCULATION IS IN SUBROUTINE BISECT, SAMPLE No. ";X X0=XA FO=FA X1=XB F1=FB XM+(XA+XB)/2 IF FO!F1>0 THEN 29250 REM FOR J=1 TO MAXI IF ABS (F1)>= ABS (PU) THEN 26800 GOTO 27100 X2=X0 XO=X1 X1=X2 F2=FO FO=F1 REM XX=X1-F1!(X1-X0)/(Fi-FO) IF XBXB THEN 27900 GOTO 27500 IF XXXA THEN 27900 REM DIFF= ABS (XX-X1) IF DIFFABS RM=XM RD=XM RETURN END RM=XX RD=XX RETURN END DISP RD=5 RETURN END REM !!!!! FUNCTION FNJI DEF FNJI (ROD) X2=ROO!ROO FNJ1=0 IF ROO >15 THEN 30200 SUM=ROO/2 TERM2=SUM I=0 I=I+1 TERM= TERM2 TERM2=-(TERM!X2!.25/(I!(I+1))) SUM=SUM+TERM2 IF ABS (TERM2)>ABS (SUM!TOL) THEN 29850 FNJ1=SUM GOTO 30250 FNJ1=SOR (2/(PI!ROO))!COS (ROO-.75!PI) FN END END REM !!!!!! SUBROUTINE SELECT1 !!!!!!!!!!!!! SELECTI: IF JJJ=1 THEN F1=FNFUN(X1) IF JJJ+2 THEN Y=FNFX1(XX) RETURN END REM !!!!!!!! SUBROUTINE SELECT2 !!!!!!!!!!!!!!!!!! SELECT2: IF JJJ=1 THEN FM=FNFUN(XM) IF JJJ+2 THEN FM=FNFX1(XM) RETURN END REM !!!!!! SUBROUTINE SELECT3 !!!!!!!!! SELECT3: IF LL=2 THEN XA=3.5 IF LL82 THEN XB=6 IF LL=3 THEN XA=6.5 (XM!TOL) THEN 26600 "ROOT NOT IN INTERVAL" !!!!!!!!!!!!! 153 APPENDIX C. (continued) 31200 IF LL=3 THEN XB=9 31250 IF LL=4 THEN XA=9.5 31300 IF LL=4 THEN XB=11 31350 IF LL=5 THEN XA=13 31400 IF LL=5 THEN X8=15 31450 IF LL=6 THEN XA=16 31500 IF LL=6 THEN XB=17 31550 IF LL>6 THEN DISP "LL > 6" ELSE 31650 31600 DISP "VALUE OUT OF RANGE" 8 END 31650 RETURN 31700 END 31750 REM !!!! DEFINITION OF FNANJO(MU,ROO) !!!!!!!!!!!!!!!! 31800 DEF FNANJO(MU,ROO) 31850 AN=2!Bi/(FNBESJ(MU)!(MU!MU+Bi!Bi)) 31900 FNANJO=AN!FNBESJ(ROO)!EXP (-FOMU12) 31950 FN END 32000 END 32050 REM !! SUBROUTINE VMUROO TO OBTAIN MU FROM ROOT EO. !! 32100 VMUROO: 32150 WW=O 32200 FA=FNFX1(XA) 32250 FB=FNFX1(XB) . 32300 GOSUB BISECT 32350 RETURN 32400 END 32450 REM !!!! DEFINITION OF FUNCTION FNFXi !!!!!!!!!!!!! 32500 DEF FNFXi (MU1) 32550 FNFX1=MU1!FNJ1(MU1)-Bi!FNBESJ (MU1) 32600 WW=WW+1 G DISP 32650 DISP " MU1=“; MU1;" ROUND No."; WW 32700 FN END 32750 END 32800 REM !!!! SUBROUTINE BISECT2 !!!!!!!!!!!!!!!! 32850 BISECT2: 32900 N1+6 8 S=.2 @ DISP "CALCULATION IS IN SUBROUTINE BISECT2" 32950 A1=XA G B=XB G WW=O 33000 A=A1 33050 N=0 33100 FOR I=1 T0 N1 33150 R(I)=INF 8 F(I)=INF G E(I)=INF 33200 NEXT I 33250 XX=A 33300 IF N>=N1 THEN 35650 33350 N=N+i 33400 GOSUB SELECTi 33450 F+Y 33500 A=A+S 33550 IF A>B THEN 35650 33600 XX=A 154 APPENDIX C. (continued) 33650 33700 33750 33800 33850 33900 33950 34000 34050 34100 34150 34200 34250 34300 34350 34400 34450 34500 34550 34600 34650 34700 34750 34800 34850 34900 34950 35000 35050 35100 35150 35200 35250 35300 35350 35400 35450 35500 35550 35600 35650 35700 GOSUB SELECT 1 P=F!Y IF P>0 THEN 33450 IF P<0 THEN 34300 IF F<> 0 THEN 34000 XX=A-S Y=F R(N)=XX F(N)=Y A=A+S Z=109-12 LET E(N)=Z GOTO 33250 L=A-S R=A C=0 XX=(L+R)/2 GOSUB SELECTi C=C+1 IF C>MAXI THEN 35300 IF ABS (Y)