蛋白酶对豆乳的凝固作用研究

以凝固时间和凝固强度为指标,考察了13种蛋白酶的豆乳凝固能力,发现胃蛋白酶、凝乳酶和风味蛋白酶没有豆乳凝固活性,Alcalase、木瓜蛋白酶和菠萝蛋白酶具有较强的豆乳凝固能力。各种蛋白酶的最适豆乳凝固温度范围比最适水解温度范围高20℃左右,豆乳凝固能力随pH的降低而增强。40℃和70℃下用蛋白酶作凝固剂得到的豆乳凝块破断强度最大为105.2Pa和148.2Pa,小于用氯化钙作凝固剂的豆乳凝块的破断强度(40℃,142.4Pa和70℃,198.4Pa),而且用酶凝固的豆乳凝块黏度较大,乳清不易排出。Alcalase具有较强的豆乳凝固能力,而且形成的豆乳凝块质地细腻,无苦味,具有一定的实际应用价值。

The clotting time and breaking strength of soymilk curds coagulated by 13 proteinases were investigated. Pepsin, rennin and flavourzyme were found to have no soymilk coagulating activity （SCA）, while Alcalase, papain and bromelain showed high activity. The optimum SCA temperature of every soymilk clotting proteinase was about 20℃ higher than that of hydrolytic activity, and the SCA value increased with the decrease of pH value. The maximum breaking strength of the proteinase coagulated soymilk curd was 105.2Pa at 40℃ and 148.2Pa at 70℃, respectively, which was lower than that of calcium coagulated soymilk curd （142.4Pa at 40℃ and 198.4Pa at 70℃）. The soymilk curd coagulated by Alcalase formed a fine texture and had no bitter taste, indicating its potential practical use for this purpose.