牛乳中乳过氧化物酶活性的影响因素

Factors Affecting Lactoperoxidase Activity in Milk

牛乳中乳过氧化物酶活性是巴氏杀菌热处理强度的重要指标,过度热处理会明显破坏牛乳本身的营养,也会导致不良物质的产生。测定经不同工艺处理后的牛乳中乳过氧化物酶活性,研究贮藏温度、贮藏时间对牛乳中乳过氧化物酶活性的影响。结果表明:经低温陶瓷膜过滤处理的牛乳中乳过氧化物酶活性损失率明显小于经75℃、15 s巴氏杀菌处理的牛乳;过多的工艺流程也会导致乳过氧化物酶活性损失,同时过高的贮藏温度会导致牛乳中乳过氧化物酶失活更快,且随着贮藏时间的延长,牛乳中乳过氧化物酶活性逐渐降低,原料乳中乳过氧化物酶活性降低更快。

The activity of lactoperoxidase in milk is an important index of the extent of pasteurization heat treatment.Excessive heat treatment will obviously destroy the nutrition of milk,and also lead to the production of some undesirable substances.In this investigation,the activity of lactoperoxidase in milk subjected to different treatments was determined,and the effect of storage temperature and time on the enzyme activity was also explored.The results showed that low-temperature ceramic membrane filtration resulted in significantly lower loss of lactoperoxidase activity than did pasteurization treatment at 75℃for 15 s.Excessive treatments also led to the loss of lactoperoxidase activity.Moreover,excessively high storage temperature led to a faster reduction of lactoperoxidase activity,and the enzyme activity gradually decreased with storage time.The activity of lactoperoxidase in raw milk decreased more rapidly than that in pasteurized milk during storage.