Effect of the activation of Lactoperoxidase System on Maintaining the Quality of Cows' raw Milk

Abstract

This study was carried out to evaluate the effect of activated Lactoperoxidase system by different levels of sodium thiocynate and sodium percarbonate, on the keeping quality of raw cow's milk. The milk was collected and used from the dairy farm, Faculty of Animal Production Science and Technology. Three levels of sodium thiocynate (12, 16, 20 mg/L) and sodium percarbonate (20, 30 40 mg/L) were used. The samples were activated at about 30 min followed by storing at 37°C for 8 hours and at 4°C for 7 days. Physiochemical and microbiological characteristics of milk were determined at 0, 2, 4, 6 and 8 hr intervals for milk stored at 37°C and 0, 1, 2, 3, 4, 5, 6 and 7 day intervals for milk stored at 4°C. In VII each case, the keeping quality of activated samples was compared with that of the control. The results showed that there were significant differences (P<0.01) between the activated and control samples. While, at 37°C and 4°C control milk samples were clearly spoiled at about the 4th hour and the 4th day, the activated milk samples were not spoiled until the end of storage period for milk stored for 8th hrs and 7 days. Also the results revealed no significant differences in milk composition (fat, protein, density and total solid) among control and activated milk samples.