牦牛乳源乳糖水解工艺及美拉德反应抑制剂的研究

The research of yak milk lactose hydrolysis and Maillard reaction inhibitors

以甘肃天祝牦牛乳为原料,在不同温度条件下通过改变酶添加量、酶解时间,以70%乳糖水解率为试验指标,优化了牦牛乳乳糖水解条件;以5-羟甲基糠醛(5-HMF)作为美拉德反应指示物,添加不同种类的抑制剂,通过测定5-HMF的抑制率评价抑制剂的抑制效果。结果表明,在40℃条件下,酶添加量为0.15%,水解3h,可使乳糖水解率达到71.1%;在6℃条件下,酶添加量为0.20%,水解20h,可使乳糖水解率达到71.3%。在85℃加热10min热处理条件下,除抗坏血酸对美拉德反应有促进作用外,维生素E、BHT、蛋氨酸和半胱氨酸均能对低乳糖牦牛乳中美拉德反应具有抑制作用,其中蛋氨酸和半胱氨酸抑制效果明显。

With Gansu Tianzhu yak milk as a raw material and the ？0% lactose hydrolytic percentage as experimentindex ,the hydrolysis condition of yak milk was optimized by changing the dosage of enzyme and hydrolysis time atdifferent temperatures.In addition, with the 5- Hydroxymethyl Furfural （5- HMF） as indicator of Maillard reaction,adding different types of inhibitors,the indicatory effects of inhibitors was evaluated by measuring the inhibitionrate of 5-HMF.The results showed that on the condition of 40℃,0.15% enzyme concentration and 3h hydrolysistime,the lactose hydrolytic percentage reached 71.1%. Moreover, under the condition of 6℃, 0.20% enzymeconcentration and 20h hydrolysis time,the lactose hydrolytic percentage reached 71.3%.Under the heat treatmentcondition at 85℃ for 10rain, vitamin E, BHT, methionine and cysteine all had inhibitory effects on the Maillardreaction in low lactose yak milk but the ascorbic acid could promote the Maillard reaction,and the inhibitory effectof methionine and cysteine were significant.