乳清蛋白凝胶条件的研究

Study on Gelatin Conditions of Whey Protein

以乳清蛋白为研究对象，研究了乳清蛋白浓度、温度、加热时间、pH值、金属离子等因素对乳清蛋白凝胶形成的作用。结果显示，乳清蛋白形成凝胶的基本条件是乳清液浓度大于0．133g／mL，温度高于85℃，当温度在85—90℃之间，凝胶形成时间随乳清蛋白浓度变大而减少，在沸水中乳清蛋白浓度对凝胶形成时间影响不大；酸性条件下乳清蛋白形成凝胶的最适pH为5.3，pH小于1．2在沸水中加热30min，乳清蛋白形成碎块状凝胶，碱性条件下形成凝胶的最适pH为83，pH大于12．8在沸水中加热30min，乳清蛋白变为红色；钙离子的添加可使乳清蛋白形成凝胶所需时间减少到6min。

Effects of whey protein concentration, temperature, heating time, pH and metal ions on gelatin formation were studied. The results showed that the conditions for gelatin formation of whey protein were： whey concentration higher 0.133 g/mL, temperature higher 85℃, the time for gelatin formation decreased as whey concentration increased between 85 ℃ and 90 ℃, the effect of whey protein concentration on gelatin formation was not distinctive in boiled water. The optimal pH for gelatin formation were respectively 5.3 and 8.3 at acidity and alkalescence, gel turned shiver and red color when pH was lower 1.2 and higher 12.8 respectively. The time for gelatin formation was reduced to 6rains by addition of Ca^2＋.