点浆条件对酸浆豆腐品质的影响

Effect of Curdling Parameters on Qualities of Fermented Soy Whey Tofu

为探究点浆时豆乳温度、点浆后蹲脑温度和蹲脑时间对酸浆豆腐品质的影响,提高酸浆豆腐品质,本研究利用质构分析、SDS-PAGE和低场核磁等技术分析了豆腐品质、豆乳中蛋白凝固过程、大豆蛋白各亚基含量和水分分布的变化规律。结果表明,点浆时豆乳温度对豆乳沉淀中蛋白和大豆蛋白各亚基含量无显著影响,但对豆腐品质和水分分布有较大影响。当点浆时豆乳温度为75℃时,豆腐的硬度最小,而其弹性、得率、含水量、保水性、感官得分和T 21弛豫时间最大。蹲脑温度和蹲脑时间对豆腐品质、豆乳沉淀中蛋白含量和大豆蛋白各亚基含量影响显著,当蹲脑温度75℃和蹲脑时间20 min时,豆腐硬度最小为15.80 N,而弹性、得率、含水量、保水性和T 21弛豫时间最佳,分别为5.15 mm、241.3%、76.36%、65.68%、43.29 ms,且豆腐品质豆乳沉淀中蛋白含量最佳。当点浆时豆乳温度为75℃、蹲脑温度为75℃和蹲脑时间20 min时,豆腐品质和感官得分最优。

To investigate the effects of soymilk temperature at the curdling,coagulation temperature and coagulation time on the quality of fermented soy whey(FSW)tofu,and to improve the quality of soy whey tofu,in this study,the changes in tofu quality,soymilk coagulation process,the content of protein subunit and water distribution using mass spectrometry,SDS-PAGE and low-field NMR techniques were analyzed.The results indicated that the soymilk temperature at the curdling had no significant effect on the protein content in soymilk precipitation,but had a significant effect on the tofu quality.When the soymilk temperature at the curdling was 75℃,the hardness of tofu was the lowest,while its elasticity,yield,water content,water retention,sensory score,T 21 fraction and relaxation time were highest.The coagulation temperature and coagulation time had a greater effect on the quality of tofu and protein content in soymilk precipitation.When the coagulation temperature and coagulation time were 75℃and 20 min,respectively,the hardness of tofu was low(15.80 N),and the best elasticity,yield,water content,water retention and relaxation time of T 21 were 5.15 mm,241.3%,76.36%,65.68%and 43.29 ms,respectively.Moreover,the protein content in soymilk precipitation of tofu quality was the highest.In conclusion,the best quality of tofu was obtained when the soymilk temperature at the curdling was 75℃,the coagulation temperature was 75℃and the coagulation time was 20 min.