Lactoperoxidase System and Its Applications in the Dairy Refreshing

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 life 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.