大豆籽粒蛋白质和磷含量及凝固剂浓度对豆腐加工品质的影响

对6个大豆品种的种子蛋白质含量、磷含量及凝固剂MgCl2浓度（0.25%、0.30%、0.35%、0.40%、0.45%）对豆腐加工品质（豆奶蛋白质浓度、豆腐硬度）的影响进行了研究。结果表明，豆奶蛋白质浓度与大豆种子蛋白质含量显著相关（r=0.93）；种子蛋白质含量与0.25% MgCl2时豆腐断裂应力的相关不显著（r=－0.11），而与最大断裂应力极

Effects of Contents of Protein and Phosphorus in Soybean Seed and Coagulant Concentrations on Processing Quality of Tofu

Effects of soybean protein content of seed, phosphorous concentration of soymilk and coagulant (MgCl_2) concentrations(0.25%, 0.30%, 0.35%, 0.40% and 0.45%) on processing quality of tofu (protein concentration of soymilk and tofu consistency) were studied using six cultivars as experimental materials. The results showed that the protein concentration of soymilk was significantly correlated with the protein content of soybean seeds, with a correlation coefficient of 0.93. The seed protein content was not correlated with the breaking stress of tofu prepared by 0.25% MgCl_2 (r=-0.11) while it exhibited a strong positive correlation (r=0.90) with maximum breaking stress. MgCl_2 concentration for the maximum breaking stress differed among the six cultivars. The tofu made from Fukuyutaka showed the highest breaking stress when prepared with 0.25% MgCl_2 and required the lowest MgCl_2 concentration for the maximum breaking stress. Therefore, Fukuyutaka is the most suitable cultivar for tofu making. Tofu made from soymilk with high phosphorous content showed lower consistency than that with low phosphorous content (normal seed) when the concentration of MgCl_2 was 0.25%, i.e. tofu with higher consistency would be got from soymilk with lower phosphorous content. When tofu consistency reached the highest, soymilk with higher phosphorous content needed higher concentration of MgCl_2 than soymilk with lower phosphorous content. But too high concentration of MgCl_2 would make tofu bitter. Within a certain MgCl_2 concentration range, tofu consistency increased with the increment of MgCl_2 concentration. But after consistency reached the highest, the consistency decreased as MgCl_2 concentration continually increased.