两种乳源切达干酪成熟期间蛋白质降解状况对比

Comparison on proteolysis during ripening of cheddar cheese-making from two different raw milk

为了了解中国特色水牛乳切达干酪成熟过程中蛋白质降解的情况,以荷斯坦牛乳切达干酪为对照,用凯氏定氮法研究两种干酪的磷钨酸可溶性氮(PTA-SN)、三氯乙酸可溶性氮(TCA-SN)和pH 4.6可溶性氮(pH 4.6-SN)在干酪成熟期间的变化情况。结果表明:在成熟期90 d内,两种切达干酪在成熟过程中PTA-SN、TCA-SN和pH 4.6-SN含量随着成熟时间的延长逐渐增大,且成熟温度越高,增加得越多,最终分别上升了约5%～10%,1%～10%,2%～5%。中国水牛乳切达干酪蛋白降解程度更深。

In order to investigate the proteolysis of Cheddar cheese made from Chinese buffalo milk, the cheese made from Holstein milk was regarded as control, the kjeldahl was used to study this two kinds of Cheddar cheeses changes of phosphotungstic acid soluble nitrogen, trichloroacetie acid soluble nitrogen and pH 4.6 soluble nitrogen, . The results indicated that： In the mature period of 90 days, the PTA-SN, TCA-SN and pH 4.6-SN of this two kinds of Cheddar cheese increased gradually with higher the temperature and more the increment, and rose about 5%-10%, 1%-10%, 2%-5%, respectively. The Cheddar cheese made from Chinese buffalo milk had deeper protein degradation.