乳过氧化物酶体系及其在乳品保鲜中的应用

Lactoperoxidase System and Its Applications in the Dairy Refreshing

本文主要介绍了乳中的一种天然抗菌活性体系—乳过氧化物酶体系(LPS),该体系由乳过氧化物酶、硫氰酸盐(SCN_)和过氧化氢(H2O2)共同组成。该体系3组分的浓度分别不低于0．5 ppm,12 ppm和8．5 ppm时,可表现出显著的抗菌效果;在30℃、25℃、20℃、15℃和3-5℃条件下,乳的保鲜期可分别达到7天、11天、16天、24天和120天。本文还介绍了乳过氧化物酶体系在乳品保鲜中的实际应用,对其应用前景进行了展望。

This paper mainly summarized one of the natural antibacterial activity systems in milk, which is called lactoperoxidase system. The characteristics, components and antibacterial mechanism of the lactoperoxidase system are summarized in the paper. The three components of the lactoperoxidase system are lactoperoxidase, thiocyanate ions and hydrogen peroxide. Results showed that concentrations of 0.5 ppm （LPO）, 15 ppm （SCN-） and 10 ppm （H2O2） would be adequate for activation of the natural lactoperoxidase systems. In particular, the lactoperoxidase system has the ability to catalyse the oxidation of thiocyanate by hydrogen peroxide with the production of the antibacterial hypothiocyanite （OSCN-） and other intermediates. These compounds, which can be further oxidized to end-products that are harmless to humans, have the ability to reduce bacterial growth by damaging the cell membrance and inhibiting the activity of many cytoplasmic enzymes. Milk preserved by lactoperoxidase system and stored at 30 ℃, 25℃, 20℃, 15℃and 3-5℃, would be kept fresh for 7 days, lldays, 16 days, 24 days and 120 days, respectively. The lower the temperature is, the longer the shelf life of the milk would be. when the temperature is low to 3-5℃,the shelf llfe can be 120 days. The progress of studies on the latest application of lactoperoxidase system in dairy refreshing, which shows wide application prospect, has also been introduced.