超高压处理对豆浆凝胶特性的影响

The Effect of Ultrahigh Pressure on the Gel Property of Soybean Milk

豆浆在２００～５００ＭＰａ超高压处理后，葡萄糖酸内酯点浆后加热时开始出现凝结的时间变迟，所形成的豆腐持水性升高、质地细腻，形成豆腐后的豆清中氮的含量降低，豆腐的得率提高。超高压的作用使得豆浆中蛋白质发生解聚和伸展，暴露了内部的－ＳＨ基团并促进二硫键的形成或交换，有利于豆浆形成豆腐。压力所导致的凝胶效果随压力的增大而增加，当压力≥３００ＭＰａ时即可使点浆后的豆浆形成质地细腻，持水性良好的豆腐凝胶。２００ＭＰａ超高压处理对豆腐的影响不大，但４００ＭＰａ超高压处理后，豆腐略有收缩并析水，豆腐的持水性下降、硬度略有增加。

After the soybean milk was treated with the pressure at the range of 200～400MPa, the clotting time increased after adding 0.25%(g/100ml) gluconolactone as a coagulation accelerator and being heated. The formed tofu had high water holding capacity and fine texture. The yield of tofu also incresead. All these changes became more obvious as the treating pressure increased. The ultrahigh pressure made protein in soybean milk disassociated and unfolded. The internal -SH groups demasked which improved the formation and exchange of disulfide bonds and benefited to the formation of tofu. The gelatination induced by pressure increased as the pressure increased. The pressure of ≥300MPa made the soybean milk added with 0.25% gluconolactone forming fine gel(tofu) with a high water holding capacity. The ultrahigh pressure treatment with the pressure at 200MPa had no effect on tofu gel. When the pressure reached 400MPa, the treated tofu had a little bit of shrinkage and water liberation. Water holding capacity of tofu decreased, and the hardness of tofu increased a little.