激活乳过氧化物酶体系对牛乳的保鲜

Influence of activating lactoperoxidase system on keeping quality of milk

用硫氰酸盐和过碳酸钠为激活剂,对牛乳中乳过氧化物酶体系(Lactoperoxidase system,LPS)进行激活,研究了在30℃条件下不同激活浓度对牛乳的pH、乳酸度、细菌总数和大肠菌群的影响.结果表明,牛乳的保鲜期与添加激活剂的浓度有关,添加中(硫氰酸钠/过碳酸钠=70∶150mg/L)、高(硫氰酸钠/过碳酸钠=140∶300 mg/L)浓度激活剂对牛乳的保鲜效果优于低(硫氰酸钠/过碳酸钠=14∶30 mg/L)浓度激活剂的处理组.添加低浓度激活剂可使牛奶新鲜度保持12 h,而中、高浓度激活剂可使牛奶新鲜度最少保持15 h.

The effects of pH, lactic acidity, total colony counts and coli group were investigated by activating Lactoperoxidase system （LPS） with adding different concentrations thiocyanate and sodium percarbonate at 30℃. The results showed that the shelf-life of milk was prolonged by activation of the LPS. The higher concentration （70：150 and 140：300 mg/L） of additives were more effective than the minimum levels （14 ： 30 mg/L） tested, The added reagents of 14 ： 30 mg/L can preserve raw milk above 12 hours, and at least 15 hours by added reagents.