转谷氨酰胺酶对牛乳酪蛋白功能性质的影响

The Effects of Transglutaminase on Functional Properties of Casein in Milk

采用微生物转谷氨酰胺酶 (TG)对牛乳中的酪蛋白进行了酶法改性 ,并对改性后牛乳中酪蛋白功能性质如溶解性、起泡性、泡沫稳定性和持水性进行了研究 .结果表明 ,牛乳经TG作用后 ,其酪蛋白功能性质发生了较大变化 ,酪蛋白的起泡性、泡沫稳定性和持水性都有不同程度的增加 ,而溶解性略有下降 .实验中考察了TG作用的时间、温度、剂量等因素对酪蛋白功能性质的影响 ,结果显示 ,要获得综合性能优良的酪蛋白 ,TG最佳的作用条件为 :pH 7.0 ,5 0℃ ,6 0min ,酶的添加量0 .1～ 0 .2U/mL .

Casein in milk was modified by transglutaminase (TG) from microorganism. Modified casein was analyzed for their functional properties, such as solubility, foaming capacity, foam stability, and water capacity ability.The results showed that the functional properties of casein greatly changed after milk was modified by transglutaminase. Foaming capacity, foam stability and water capacity ability of casein were improved to different degrees. Solubility of modified casein was reduced slightly .In addition, the optimum conditions of TG reaction were obtained: pH 7.0, incubation time 60 min, enzyme concentration 0.1～0.2 U/mL, and reaction temperature 50 ℃.