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Determination of the upper temperature limit of water loss by food systems
Food Hydrocolloids 25 (2011) 283e285
Contents lists available at ScienceDirect
Food Hydrocolloids journal homepage: www.elsevier.com/locate/foodhyd
Determination of the upper temperature limit of water loss by food systems Yu. I. Matveev* Institute of Biochemical Physics, Russian Academy of Sciences, Kosygin Street 4, Moscow GSP1 119334, Russian Federation
a r t i c l e i n f o
a b s t r a c t
Article history: Received 9 October 2008 Accepted 6 June 2010
A method for estimation of the upper temperature limit of water loss by food systems during preservation (drying, baking, extrusion, smoking, etc.) is proposed. These temperatures are related to the lower and higher critical solution temperatures, which were shown to depend on the chemical structure of system components. A determination method for the lower and higher critical solution temperatures in the plasticization curves obtained by calorimetry was developed. Ó 2010 Elsevier Ltd. All rights reserved.
Keywords: Water Glass transition temperature Proteins Monosaccharides Disaccharides Polysaccharides Plasticization Lower and higher critical solution temperatures
1. Introduction Previously (Ablett, Izzard, & Lillford, 1992; Levine & Slade, 1986; Roos, 1995; Slade & Levine, 1995), it was shown that on freezing, food substances plasticized by water retain moisture down to certain temperature Tg0 and the corresponding concentration Cg0 . Further decrease in temperature results in water loss. The parameters Tg0 and Cg0 depend on the chemical structure of substances and can be calculated (Matveev, 2004; Matveev & Ablett, 2002). Similar characteristic temperatures exist for preservation of plasticized food substances when a food system starts losing moisture on temperature rise. Elevated temperatures are widely used in various food processes, for instance, in baking bread or confectioneries, drying fruits or vegetables, smoking and jerking of fish, meat, etc. In what follows the processes related to water loss during preservation are called high-temperature processes (as opposed to freezing). Analysis of various preservation processes shows that they proceed in a particular temperature range the boundaries of which can be associated with the lower and higher critical solution temperatures (LCST e ql and HCST e qu). In this temperature range, the substances that form a food system turn into a gel (they form thermoreversible gels). The specific nature of thermoreversible gels (Papkov, 1974) is that they tend to undergo microstratification, i.e.,
they can have both LCST and HCST (Tager, 1978). In the thermodynamic limit, they form two phases. However, in infinite systems, such stratification occurs very slowly because of kinetic difficulties. If we consider a finite system having a limited external surface, water released upon microstratification goes out through this surface. The higher the temperature, the more intensive the water loss. Being able to calculate ql and qu of different components that form the given food system, we can select a chemical model (basic components) determining the temperature range for its processing. When estimating ql and qu of a food systems we will restrict ourselves to four processes: processing of milk products, baking, drying and fermentation, although the approaches proposed can also be used for analysis of processing temperatures Tpr for other food preservation processes. They are determined using calculation schemes (Matveev, 2000) that take into account the influence of chemical structure and solute concentration on ql and qu. Table 1 presents the basic food products and substances that can be used to simulate processing processes. The proposed approaches are further development of the Levine & Slade works in which methods of polymer physicochemistry were used for the description of thermodynamic and kinetic properties of food systems.
2. Basic correlations * Fax: þ7 95 137 41 01. E-mail address: [email protected] 0268-005X/$ e see front matter Ó 2010 Elsevier Ltd. All rights reserved. doi:10.1016/j.foodhyd.2010.06.004
Below we consider basic correlations that will be used to analyze food preservation processes. According to Matveev (2000),
284
Yu.I. Matveev / Food Hydrocolloids 25 (2011) 283e285
3. Analysis of preservation processes
Table 1 ql and qu for various food substances. Material
Tgs ( C)
ql ( C)
qu ( C)
Dairy foods Curd, cheese Milk proteins a-, b-, k-Caseins a-Lactalbumin b-Lactoglobulin
97b 164e165c 151c 155c
28e33 28 26
98e99 99 99
Meat foods Ham Bacon Pepperoni Meat proteins L-meromyosin T-meromyosin Actin Gelatin
Tpr ( C)
45e82d 35e49d 35e55d 151c 156c 162c 200c
30 34 37 56
99 99 99 96 55e112a, 51f
Bread baking Pasta extrusion Corn proteins and starch Wheat glutenin 175c Wheat gliadin 186c Amylose 302c Amylopectin 294c
35 39 77 76
92 99 117 117
Dried fruit and vegetables Apple Apricot Cherries Potato Mono-, disaccharides, polysaccharides Glucose 36c Sucrose 67c Cellulose 161g Pectin 195g
e
55e75h 50e70h 55e70h 75e85h 7 13 28 56
91 94 99 96
a The low temperature limit corresponds to the beginning of starch gelation and the high-temperature limit corresponds to the temperature of the crust formation. Temperatures of the state change of protein substances and the end of starch gelation fall into this temperature range. b Marshall (1986). c Matveev (2004). d Sebranek and Bacus (2007). e Auerman (1956). f Walsh and Gilles (1977). g Askadskii (2003). h FAO (1995).
the ql and qu values of aqueous solutions of biopolymers can be determined from equations
qi ¼ Tm þ Tgo xi ; where x1;2 ¼ 0:158ð1 1:473ðTm =Tgo 0:537Þ0:5 Þ, qu has the plus sign in the expression for x1,2, ql has the minus sign, Tm is the melting point of water, Tgo is the glass transition temperature of dry polymer at a polymerization degree N greater than the critical value Nc. Values of Tgo as function of the biopolymer chemical structures can be calculated on data of paper (Matveev, Slade, & Levine, 1999). The effect of the polymer concentration P on q-temperatures is taken into account through x1,2 by means of the equation (Matveev, 2000)
x1;2 ¼ 0:158 f1 ðPÞ 1:473 f1 ðPÞTm =Tgo 0:998 0:5 ; þ 0:461f1 ðPÞ2 where f1(P) ¼ 1 þ 0.172hoP, ho ¼ 0.035 mg/ml.
(1)
Depending on the process of the initial product treatment (Table 1), one or another q temperature is used. By selecting the q temperature near to Tpr for a corresponding component, one can define more precisely the chemical model of the given food system. For example, for preparation of curd or cheese (milk protein separation), the Tpr w qu temperatures of milk proteins are used. Ham fermentation takes place at ql < Tpr < qu, where ql corresponds to the q temperature of actin and qu corresponds to the q temperature of gelatin. The bacon and pepperoni fermentation takes place at qu < Tpr < ql, where ql corresponds to the q temperature of gelatin and qu corresponds to the q temperature of T-meromyosin. Starch-containing products (bread, pasta) are worthy of special note. Usually starches are insoluble in water and form suspensions. Therefore, ql can be considered as the gelation point. In the temperature range from ql to qu, starch turns into a gel. This range corresponds to bread crumb formation. However, at T > qu, the gel starts to lose water. This is the range of chemical reactions between the starch molecules and proteins, for instance, the formation of glycoproteins (crust) during bread baking. The situation with pasta is different. During pasta extrusion, the process temperature does not exceed ql of starch, i.e. no gelation takes place. In this range, changes in the state of proteins are the main processes. The lower limit of fruit drying temperature is determined by the pectin ql and the higher limit is determined by the glucose qu, i.e., ql(pectin) < Tpr < qu(glucose). In the case of potato, the drying process is realized at about ql(starch) when the starch gelation only starts. Thus, the ql and qu temperatures of components of various food substances fully determine the temperatures range for the preparation of particular foodstuffs.
4. Plasticization process and characteristic temperatures ql and qu Estimations of ql and qu of different biopolymers and saccharides (Table 1) show that these temperatures fit on a plasticization curve. Since the gelation process starts at T ql in the biopolymerewater system, in the temperature range DT ¼ qu ql, the plasticization function follows a different concentration dependence than in the case of biopolymerewater system when the change in the state of the system is not taken into account (Couchman, 1987; Matveev, Grinberg, & Tolstoguzov, 2000). As an example, consider the experimental dependence of Tg of pea amylase on the water content W (Bizot et al., 1997). Whereas the approximation curve (for instance, Couchman equation) is smooth in the water concentration region W* < W < W0, the real experimental curve deviates from the smooth curve in the temperature region ql T qu (Fig. 1). The plasticization function change in the gelation region is insignificant (Bizot et al., 1997). However, this allows one to find the ql and qu temperatures from calorimetry data, which is important for selecting the thermal conditions for preservation of various food substances. The ql and qu determination procedure is as follows. From experimental data Tg(W) (for instance, Bizot et al., 1997), only those values are taken that are beyond the qu ql range (qland qu are estimated by calculations). They are approximated by means of the Couchman equation TgC(W). Then TgC(W) values are subtracted from experimental Tg(W) and the points where Tg(W) TgC(W) ¼ 3 are determined (3 is the approximation error). The corresponding W values are Wu and Wl, and TgC(Wu) ¼ qu, TgC(Wl) ¼ ql, i.e. ql and qu values will be determined more precisely from experiments.
Yu.I. Matveev / Food Hydrocolloids 25 (2011) 283e285
285
plasticization function on the plasticizer concentration, which are attributed most often to measurement errors, and allow using the plasticization function for determination of q-temperatures. References
Fig. 1. Schematic representation of the biopolymer glass transition temperature Tg(W) vs. the weight fraction of water W. Characteristic points: ql and qu are the LCST and HCST, Wl and Wu are the corresponding weight fractions of water, W* is the weight fraction of water at which the accessible hydrogen bonds are blocked (Matveev, 2000), W0 is the maximum water quantity bound by the plasticized biopolymer. In the case of starch W* ¼ 0.04, ql ¼ 76 C, qu ¼ 117 C, Wl ¼ 0.145, Wu ¼ 0.102, W0 ¼ 0.28 (Bizot et al., 1997). The dotted line marks the region of gelatinous state.
5. Conclusion The results of estimation of ql and qu temperatures of food substance components show (Table 1) that they fully determine the temperature range of food processing. This allows active use of ql and qu temperatures for determination of treatment process parameters for new food products or for improving the quality of existing processes. Usually, theoretic descriptions of polymer plasticization consider only the polymer interaction with plasticizer but do not take into account the change in the system state vs. the plasticizer concentration. Taking into account the polymereplasticizer system state, the temperatures of transition from one state to another provide explanation for the complicated temperature dependences of the
Ablett, S., Izzard, M. J., & Lillford, P. J. (1992). Differential scanning calorimetric study of frozen sucrose and glycerol solutions. Journal of Chemical Society, Faraday Transactions 1, 88(6), 789e794. Askadskii, A. A. (2003). Computational materials science of polymers. Cambridge: International Science Publishing. Auerman, L. Ya. (1956). Technology of bread-baking. Moscow: Pishepromizdat. (in Russia). Bizot, H., Le Bail, P., Leroux, B., Davy, J., Roger, P., & Buleon, A. (1997). Calorimetric evaluation of the glass transition in hydrated, linear and branched polyanhydroglucose compounds. Carbohydrate Polymers, 32, 33e50. Couchman, P. R. (1987). The glass transition of compatible blends. Polymer Engineering and Science, 27, 618e621. FAO. (1995). Fruit and vegetable processing. Agricultural service bulletin, no. 119. Levine, H., & Slade, L. (1986). A polymer physicochemical approach to the study of commercial starch hydrolysis products (SHPs). Carbohydrate Polymers, 6, 213e244. Marshall, K. R. (1986). Industrial isolation of milk proteins: whey proteins in developments in dairy chemistry-1. In P. F. Fox (Ed.), Dairy technology (pp. 339e374). London & New York: Elsevier Applied Science Publishers Ltd. Matveev, Yu. I. (2000). Calculation of the q-temperatures of biopolymer solutions. Polymer Science A, 42(9), 1030e1037. 0 0 Matveev, Yu. I. (2004). Modification of the method for calculation of the Cg and Tg intersection point in the state diagrams of frozen solution. Food Hydrocolloids, 18, 363e366. 0 0 Matveev, Yu. I., & Ablett, S. (2002). Calculation of the Cg and Tg intersection point in the state diagram of frozen solution. Food Hydrocolloids, 16, 419e422. Matveev, Yu. I., Grinberg, V. Ya., & Tolstoguzov, V. B. (2000). The plasticizing effect of water on proteins, polysaccharides and their mixtures. Glassy state of biopolymers, food and seeds. Food Hydrocolloids, 14, 425e437. Matveev, Yu. I., Slade, L., & Levine, H. (1999). Determination of the main technological parameters of food substances by means of the additive contribution method. Food Hydrocolloids, 13, 381e388. Papkov, S. P. (1974). Gelatinous state of polymers. Moscow: Khimiya. (in Russian). Roos, Y. H. (1995). Phase transitions in foods. New York: Academic Press. Sebranek, J., & Bacus, J. (2007). Natural and organic cured meat products: regulatory, manufacturing, marketing, quality and safety issues (pp. 1e15). American Meat Science Association, March, N1. Slade, L., & Levine, H. (1995). Glass transition and waterefood structure interactions. In S. L. Taylor, & J. E. Kinsella (Eds.), Advances in food and nutrition research, Vol. 38 (pp. 103e269). San Diego, CA: Academic Press. Tager, A. A. (1978). Physicochemistry of polymers. Moscow: Khimia. (in Russia). Walsh, D. E., & Gilles, K. A. (1977). Pasta technology. In N. W. Desrosier (Ed.), Elements of food technology (pp. 502e517). Westport, CT: AVI Publishing Company, Inc.
Contents lists available at ScienceDirect
Food Hydrocolloids journal homepage: www.elsevier.com/locate/foodhyd
Determination of the upper temperature limit of water loss by food systems Yu. I. Matveev* Institute of Biochemical Physics, Russian Academy of Sciences, Kosygin Street 4, Moscow GSP1 119334, Russian Federation
a r t i c l e i n f o
a b s t r a c t
Article history: Received 9 October 2008 Accepted 6 June 2010
A method for estimation of the upper temperature limit of water loss by food systems during preservation (drying, baking, extrusion, smoking, etc.) is proposed. These temperatures are related to the lower and higher critical solution temperatures, which were shown to depend on the chemical structure of system components. A determination method for the lower and higher critical solution temperatures in the plasticization curves obtained by calorimetry was developed. Ó 2010 Elsevier Ltd. All rights reserved.
Keywords: Water Glass transition temperature Proteins Monosaccharides Disaccharides Polysaccharides Plasticization Lower and higher critical solution temperatures
1. Introduction Previously (Ablett, Izzard, & Lillford, 1992; Levine & Slade, 1986; Roos, 1995; Slade & Levine, 1995), it was shown that on freezing, food substances plasticized by water retain moisture down to certain temperature Tg0 and the corresponding concentration Cg0 . Further decrease in temperature results in water loss. The parameters Tg0 and Cg0 depend on the chemical structure of substances and can be calculated (Matveev, 2004; Matveev & Ablett, 2002). Similar characteristic temperatures exist for preservation of plasticized food substances when a food system starts losing moisture on temperature rise. Elevated temperatures are widely used in various food processes, for instance, in baking bread or confectioneries, drying fruits or vegetables, smoking and jerking of fish, meat, etc. In what follows the processes related to water loss during preservation are called high-temperature processes (as opposed to freezing). Analysis of various preservation processes shows that they proceed in a particular temperature range the boundaries of which can be associated with the lower and higher critical solution temperatures (LCST e ql and HCST e qu). In this temperature range, the substances that form a food system turn into a gel (they form thermoreversible gels). The specific nature of thermoreversible gels (Papkov, 1974) is that they tend to undergo microstratification, i.e.,
they can have both LCST and HCST (Tager, 1978). In the thermodynamic limit, they form two phases. However, in infinite systems, such stratification occurs very slowly because of kinetic difficulties. If we consider a finite system having a limited external surface, water released upon microstratification goes out through this surface. The higher the temperature, the more intensive the water loss. Being able to calculate ql and qu of different components that form the given food system, we can select a chemical model (basic components) determining the temperature range for its processing. When estimating ql and qu of a food systems we will restrict ourselves to four processes: processing of milk products, baking, drying and fermentation, although the approaches proposed can also be used for analysis of processing temperatures Tpr for other food preservation processes. They are determined using calculation schemes (Matveev, 2000) that take into account the influence of chemical structure and solute concentration on ql and qu. Table 1 presents the basic food products and substances that can be used to simulate processing processes. The proposed approaches are further development of the Levine & Slade works in which methods of polymer physicochemistry were used for the description of thermodynamic and kinetic properties of food systems.
2. Basic correlations * Fax: þ7 95 137 41 01. E-mail address: [email protected] 0268-005X/$ e see front matter Ó 2010 Elsevier Ltd. All rights reserved. doi:10.1016/j.foodhyd.2010.06.004
Below we consider basic correlations that will be used to analyze food preservation processes. According to Matveev (2000),
284
Yu.I. Matveev / Food Hydrocolloids 25 (2011) 283e285
3. Analysis of preservation processes
Table 1 ql and qu for various food substances. Material
Tgs ( C)
ql ( C)
qu ( C)
Dairy foods Curd, cheese Milk proteins a-, b-, k-Caseins a-Lactalbumin b-Lactoglobulin
97b 164e165c 151c 155c
28e33 28 26
98e99 99 99
Meat foods Ham Bacon Pepperoni Meat proteins L-meromyosin T-meromyosin Actin Gelatin
Tpr ( C)
45e82d 35e49d 35e55d 151c 156c 162c 200c
30 34 37 56
99 99 99 96 55e112a, 51f
Bread baking Pasta extrusion Corn proteins and starch Wheat glutenin 175c Wheat gliadin 186c Amylose 302c Amylopectin 294c
35 39 77 76
92 99 117 117
Dried fruit and vegetables Apple Apricot Cherries Potato Mono-, disaccharides, polysaccharides Glucose 36c Sucrose 67c Cellulose 161g Pectin 195g
e
55e75h 50e70h 55e70h 75e85h 7 13 28 56
91 94 99 96
a The low temperature limit corresponds to the beginning of starch gelation and the high-temperature limit corresponds to the temperature of the crust formation. Temperatures of the state change of protein substances and the end of starch gelation fall into this temperature range. b Marshall (1986). c Matveev (2004). d Sebranek and Bacus (2007). e Auerman (1956). f Walsh and Gilles (1977). g Askadskii (2003). h FAO (1995).
the ql and qu values of aqueous solutions of biopolymers can be determined from equations
qi ¼ Tm þ Tgo xi ; where x1;2 ¼ 0:158ð1 1:473ðTm =Tgo 0:537Þ0:5 Þ, qu has the plus sign in the expression for x1,2, ql has the minus sign, Tm is the melting point of water, Tgo is the glass transition temperature of dry polymer at a polymerization degree N greater than the critical value Nc. Values of Tgo as function of the biopolymer chemical structures can be calculated on data of paper (Matveev, Slade, & Levine, 1999). The effect of the polymer concentration P on q-temperatures is taken into account through x1,2 by means of the equation (Matveev, 2000)
x1;2 ¼ 0:158 f1 ðPÞ 1:473 f1 ðPÞTm =Tgo 0:998 0:5 ; þ 0:461f1 ðPÞ2 where f1(P) ¼ 1 þ 0.172hoP, ho ¼ 0.035 mg/ml.
(1)
Depending on the process of the initial product treatment (Table 1), one or another q temperature is used. By selecting the q temperature near to Tpr for a corresponding component, one can define more precisely the chemical model of the given food system. For example, for preparation of curd or cheese (milk protein separation), the Tpr w qu temperatures of milk proteins are used. Ham fermentation takes place at ql < Tpr < qu, where ql corresponds to the q temperature of actin and qu corresponds to the q temperature of gelatin. The bacon and pepperoni fermentation takes place at qu < Tpr < ql, where ql corresponds to the q temperature of gelatin and qu corresponds to the q temperature of T-meromyosin. Starch-containing products (bread, pasta) are worthy of special note. Usually starches are insoluble in water and form suspensions. Therefore, ql can be considered as the gelation point. In the temperature range from ql to qu, starch turns into a gel. This range corresponds to bread crumb formation. However, at T > qu, the gel starts to lose water. This is the range of chemical reactions between the starch molecules and proteins, for instance, the formation of glycoproteins (crust) during bread baking. The situation with pasta is different. During pasta extrusion, the process temperature does not exceed ql of starch, i.e. no gelation takes place. In this range, changes in the state of proteins are the main processes. The lower limit of fruit drying temperature is determined by the pectin ql and the higher limit is determined by the glucose qu, i.e., ql(pectin) < Tpr < qu(glucose). In the case of potato, the drying process is realized at about ql(starch) when the starch gelation only starts. Thus, the ql and qu temperatures of components of various food substances fully determine the temperatures range for the preparation of particular foodstuffs.
4. Plasticization process and characteristic temperatures ql and qu Estimations of ql and qu of different biopolymers and saccharides (Table 1) show that these temperatures fit on a plasticization curve. Since the gelation process starts at T ql in the biopolymerewater system, in the temperature range DT ¼ qu ql, the plasticization function follows a different concentration dependence than in the case of biopolymerewater system when the change in the state of the system is not taken into account (Couchman, 1987; Matveev, Grinberg, & Tolstoguzov, 2000). As an example, consider the experimental dependence of Tg of pea amylase on the water content W (Bizot et al., 1997). Whereas the approximation curve (for instance, Couchman equation) is smooth in the water concentration region W* < W < W0, the real experimental curve deviates from the smooth curve in the temperature region ql T qu (Fig. 1). The plasticization function change in the gelation region is insignificant (Bizot et al., 1997). However, this allows one to find the ql and qu temperatures from calorimetry data, which is important for selecting the thermal conditions for preservation of various food substances. The ql and qu determination procedure is as follows. From experimental data Tg(W) (for instance, Bizot et al., 1997), only those values are taken that are beyond the qu ql range (qland qu are estimated by calculations). They are approximated by means of the Couchman equation TgC(W). Then TgC(W) values are subtracted from experimental Tg(W) and the points where Tg(W) TgC(W) ¼ 3 are determined (3 is the approximation error). The corresponding W values are Wu and Wl, and TgC(Wu) ¼ qu, TgC(Wl) ¼ ql, i.e. ql and qu values will be determined more precisely from experiments.
Yu.I. Matveev / Food Hydrocolloids 25 (2011) 283e285
285
plasticization function on the plasticizer concentration, which are attributed most often to measurement errors, and allow using the plasticization function for determination of q-temperatures. References
Fig. 1. Schematic representation of the biopolymer glass transition temperature Tg(W) vs. the weight fraction of water W. Characteristic points: ql and qu are the LCST and HCST, Wl and Wu are the corresponding weight fractions of water, W* is the weight fraction of water at which the accessible hydrogen bonds are blocked (Matveev, 2000), W0 is the maximum water quantity bound by the plasticized biopolymer. In the case of starch W* ¼ 0.04, ql ¼ 76 C, qu ¼ 117 C, Wl ¼ 0.145, Wu ¼ 0.102, W0 ¼ 0.28 (Bizot et al., 1997). The dotted line marks the region of gelatinous state.
5. Conclusion The results of estimation of ql and qu temperatures of food substance components show (Table 1) that they fully determine the temperature range of food processing. This allows active use of ql and qu temperatures for determination of treatment process parameters for new food products or for improving the quality of existing processes. Usually, theoretic descriptions of polymer plasticization consider only the polymer interaction with plasticizer but do not take into account the change in the system state vs. the plasticizer concentration. Taking into account the polymereplasticizer system state, the temperatures of transition from one state to another provide explanation for the complicated temperature dependences of the
Ablett, S., Izzard, M. J., & Lillford, P. J. (1992). Differential scanning calorimetric study of frozen sucrose and glycerol solutions. Journal of Chemical Society, Faraday Transactions 1, 88(6), 789e794. Askadskii, A. A. (2003). Computational materials science of polymers. Cambridge: International Science Publishing. Auerman, L. Ya. (1956). Technology of bread-baking. Moscow: Pishepromizdat. (in Russia). Bizot, H., Le Bail, P., Leroux, B., Davy, J., Roger, P., & Buleon, A. (1997). Calorimetric evaluation of the glass transition in hydrated, linear and branched polyanhydroglucose compounds. Carbohydrate Polymers, 32, 33e50. Couchman, P. R. (1987). The glass transition of compatible blends. Polymer Engineering and Science, 27, 618e621. FAO. (1995). Fruit and vegetable processing. Agricultural service bulletin, no. 119. Levine, H., & Slade, L. (1986). A polymer physicochemical approach to the study of commercial starch hydrolysis products (SHPs). Carbohydrate Polymers, 6, 213e244. Marshall, K. R. (1986). Industrial isolation of milk proteins: whey proteins in developments in dairy chemistry-1. In P. F. Fox (Ed.), Dairy technology (pp. 339e374). London & New York: Elsevier Applied Science Publishers Ltd. Matveev, Yu. I. (2000). Calculation of the q-temperatures of biopolymer solutions. Polymer Science A, 42(9), 1030e1037. 0 0 Matveev, Yu. I. (2004). Modification of the method for calculation of the Cg and Tg intersection point in the state diagrams of frozen solution. Food Hydrocolloids, 18, 363e366. 0 0 Matveev, Yu. I., & Ablett, S. (2002). Calculation of the Cg and Tg intersection point in the state diagram of frozen solution. Food Hydrocolloids, 16, 419e422. Matveev, Yu. I., Grinberg, V. Ya., & Tolstoguzov, V. B. (2000). The plasticizing effect of water on proteins, polysaccharides and their mixtures. Glassy state of biopolymers, food and seeds. Food Hydrocolloids, 14, 425e437. Matveev, Yu. I., Slade, L., & Levine, H. (1999). Determination of the main technological parameters of food substances by means of the additive contribution method. Food Hydrocolloids, 13, 381e388. Papkov, S. P. (1974). Gelatinous state of polymers. Moscow: Khimiya. (in Russian). Roos, Y. H. (1995). Phase transitions in foods. New York: Academic Press. Sebranek, J., & Bacus, J. (2007). Natural and organic cured meat products: regulatory, manufacturing, marketing, quality and safety issues (pp. 1e15). American Meat Science Association, March, N1. Slade, L., & Levine, H. (1995). Glass transition and waterefood structure interactions. In S. L. Taylor, & J. E. Kinsella (Eds.), Advances in food and nutrition research, Vol. 38 (pp. 103e269). San Diego, CA: Academic Press. Tager, A. A. (1978). Physicochemistry of polymers. Moscow: Khimia. (in Russia). Walsh, D. E., & Gilles, K. A. (1977). Pasta technology. In N. W. Desrosier (Ed.), Elements of food technology (pp. 502e517). Westport, CT: AVI Publishing Company, Inc.