石膏豆腐凝胶特性的研究
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摘要
豆腐凝胶特性与豆腐的品质和产率直接相关,豆腐凝胶特性与豆腐生产工艺参数相关性研究将为豆腐生产的标准化和自动化奠定理论基础。本研究从动态流变特性,质构特性和微观结构特征等方面对石膏豆腐的凝胶特性进行了表征,研究了硫酸钙含量和凝固温度对豆腐凝胶特性的影响。研究表明:在硫酸钙含量为20~50 m M时,豆腐凝胶均在85℃时获得最高的储能模量,并且凝胶过程符合一级反应动力学;在硫酸钙含量相同时,豆腐凝胶的硬度随温度的升高而升高。当硫酸钙含量为20 m M或30 m M时,豆腐凝胶网络细腻松散,且持水率都在85℃时达到最高值;随着温度升高,豆腐凝胶的弹性升高,凝胶网络变粗厚且网孔增大。当硫酸钙含量为40 m M或50 m M时,豆腐凝胶网络粗厚缜密,持水率分别在80℃和75℃时达到最高值;随着温度升高,豆腐凝胶弹性降低,孔隙增大且呈现不规则形貌。
The coagulation process is an extremely crucial step during preparation of plaster tofu as the quality and yield of tofu are influenced by the gelling properties during this process. The gelling properties of plaster tofu were characterized by dynamic rheological testing, texture analysis, and scanning electron microscopy, considering changes in coagulation temperature and calcium sulfate concentration. Dynamic viscoelastic testing showed that the highest storage modulus of tofu gel is obtained at 85 ℃ regardless of the calcium sulfate concentration, and the relationship between storage modulus and coagulant temperature followed first-order reaction kinetics. Texture analysis revealed that the hardness of tofu increased with increasing coagulation temperature at a calcium sulfate concentration of 20~50 m M. At the calcium sulfate concentration of 20 m M or 30 m M, the tofu gel was fragile with a loose gel network, which gradually became thicker and more elastic with increased pore size as the coagulation temperature increased, and the highest water holding capacity was reached at 85 ℃. At the calcium sulfate concentration of 40 m M or 50 m M, elasticity of the tofu gel decreased with an increase in coagulation temperature; the tofu gel was thick and dense, and larger pore size and irregular morphology were observed with an increase in coagulation temperature. The highest water holding capacity of tofu gel was obtained at 80 ℃ and 75 ℃.
The coagulation process is an extremely crucial step during preparation of plaster tofu as the quality and yield of tofu are influenced by the gelling properties during this process. The gelling properties of plaster tofu were characterized by dynamic rheological testing, texture analysis, and scanning electron microscopy, considering changes in coagulation temperature and calcium sulfate concentration. Dynamic viscoelastic testing showed that the highest storage modulus of tofu gel is obtained at 85 ℃ regardless of the calcium sulfate concentration, and the relationship between storage modulus and coagulant temperature followed first-order reaction kinetics. Texture analysis revealed that the hardness of tofu increased with increasing coagulation temperature at a calcium sulfate concentration of 20~50 m M. At the calcium sulfate concentration of 20 m M or 30 m M, the tofu gel was fragile with a loose gel network, which gradually became thicker and more elastic with increased pore size as the coagulation temperature increased, and the highest water holding capacity was reached at 85 ℃. At the calcium sulfate concentration of 40 m M or 50 m M, elasticity of the tofu gel decreased with an increase in coagulation temperature; the tofu gel was thick and dense, and larger pore size and irregular morphology were observed with an increase in coagulation temperature. The highest water holding capacity of tofu gel was obtained at 80 ℃ and 75 ℃.
引文
[1]Yoko T,K Tomokazu.Tofu(soybean curd)lowers serum lipid levels and modulates hepatic gene expression involved in lipogenesis primarily through its protein,not isoflavone,component in rats[J].J.of Agric.Food Chem.,2011,59(16):8976-8984
[2]Shurtleff W.Principles of tofu and soymilk production.In tofu and soymilk production[J].The Soyfoods Center:Lafayette,1990:123-126
[3]Shih M C,Hou H J,Chang K C.Process optimization for soft tofu[J].Journal of Food Science,1997,62(4):833-837
[4]Murdia L K,Wadhwani R.Effect of processing parameters on texture and yield of tofu[J].Asian Journal of Food and Agro-industry,2010,3(20):232-241
[5]Cai T D,Chang K C.Characteristics of production-scale tofu as affected by soymilk coagulation method:propeller blade size,mixing time and coagulant concentration[J].Food Research International,1998,31(4):289-295
[6]Wang L,Li L T,Tatsumi E,et al.Application of two-stage ohmic heating to tofu processing[J].Chemical Engineering and Processing,2006,46(5):486-490
[7]Juin K F,Wei S N,Hsiung L M.Effect of calcium sulfate concentration in soymilk on the microstructure of firm tofu and the protein constitutions in tofu whey[J].Journal of Agricultural and Food Chemistry,2003,51(21):6211-6216
[8]刘香英,田志刚,康立宁.大豆品种和凝固剂种类对豆腐保水性的影响[J].吉林农业科学,2012,6:56-60LIU Xiang-ying,TIAN Zhi-gang,KANG Li-ning.Effects of soybean varieties and coagulant types on the water holding capacity of tofu[J].Journal of Jilin Agricultural Sciences,2012,6:56-60
[9]Onodera Y,Ono T,Nakasato K,et.al.Homogeneity and microstructure of tofu depends on 11S/7S globulin ratio in soymilk and coagulant concentration[J].Food Science and Technology Research,2009,15(3):265-274
[10]Pang Z,Deeth H,Sopade P,et al.Rheology,texture and microstructure of gelatin gels with and without milk proteins[J].Food Hydrocolloids,2014,35(3):484-493
[11]Kamizake N K K,Silva L C P,Prudencio S H.Effect of soybean aging on the quality of soymilk,firmness of tofu and optimum coagulant concentration[J].Food Chemistry,2016,190:90-96
[12]Kohyama K,Sano Y,Doi E.Rheological characteristics and gelation mechanism of tofu(soybean curd)[J].Journal of Agricultural and Food Chemistry,1995,43(7):1808-1812
[13]Lee C Y,Kuo M I.Effect ofγ-polyglutamate on the rheological properties and microstructure of tofu[J].Food Hydrocolloids,2011,25(5):1034-1040
[14]Prabhakaran M P,Pereca C O,Valiyaveettil S.Effect of different coagulants on the isoflavone levels and physical properties of prepared firm tofu[J].Food Chemistry,2006,99(3):492-499
[2]Shurtleff W.Principles of tofu and soymilk production.In tofu and soymilk production[J].The Soyfoods Center:Lafayette,1990:123-126
[3]Shih M C,Hou H J,Chang K C.Process optimization for soft tofu[J].Journal of Food Science,1997,62(4):833-837
[4]Murdia L K,Wadhwani R.Effect of processing parameters on texture and yield of tofu[J].Asian Journal of Food and Agro-industry,2010,3(20):232-241
[5]Cai T D,Chang K C.Characteristics of production-scale tofu as affected by soymilk coagulation method:propeller blade size,mixing time and coagulant concentration[J].Food Research International,1998,31(4):289-295
[6]Wang L,Li L T,Tatsumi E,et al.Application of two-stage ohmic heating to tofu processing[J].Chemical Engineering and Processing,2006,46(5):486-490
[7]Juin K F,Wei S N,Hsiung L M.Effect of calcium sulfate concentration in soymilk on the microstructure of firm tofu and the protein constitutions in tofu whey[J].Journal of Agricultural and Food Chemistry,2003,51(21):6211-6216
[8]刘香英,田志刚,康立宁.大豆品种和凝固剂种类对豆腐保水性的影响[J].吉林农业科学,2012,6:56-60LIU Xiang-ying,TIAN Zhi-gang,KANG Li-ning.Effects of soybean varieties and coagulant types on the water holding capacity of tofu[J].Journal of Jilin Agricultural Sciences,2012,6:56-60
[9]Onodera Y,Ono T,Nakasato K,et.al.Homogeneity and microstructure of tofu depends on 11S/7S globulin ratio in soymilk and coagulant concentration[J].Food Science and Technology Research,2009,15(3):265-274
[10]Pang Z,Deeth H,Sopade P,et al.Rheology,texture and microstructure of gelatin gels with and without milk proteins[J].Food Hydrocolloids,2014,35(3):484-493
[11]Kamizake N K K,Silva L C P,Prudencio S H.Effect of soybean aging on the quality of soymilk,firmness of tofu and optimum coagulant concentration[J].Food Chemistry,2016,190:90-96
[12]Kohyama K,Sano Y,Doi E.Rheological characteristics and gelation mechanism of tofu(soybean curd)[J].Journal of Agricultural and Food Chemistry,1995,43(7):1808-1812
[13]Lee C Y,Kuo M I.Effect ofγ-polyglutamate on the rheological properties and microstructure of tofu[J].Food Hydrocolloids,2011,25(5):1034-1040
[14]Prabhakaran M P,Pereca C O,Valiyaveettil S.Effect of different coagulants on the isoflavone levels and physical properties of prepared firm tofu[J].Food Chemistry,2006,99(3):492-499