Fatty Acid Variation of Pasteurized Milk under Different Processing Temperatures and Storage Periods

This study aimed to analyze the impact of different pasteurization temperatures and storage periods on fatty acid composition of pasteurized milk.Raw milk was pasteurized at 65 ℃ for 30 min or at 85 ℃ for 15 s,sealed and then stored at 4 ℃.The fatty acid composition of raw milk and pasteurized milk during storage was analyzed by gas chromatography.The results indicated no significant difference in fatty acid composition was present among pasteurized milks treated at different temperature(P 0.05).In addition,the fatty acid composition of pasteurized milk was quite stable during storage.However,the content of fatty acid C4:0 in pasteurized milk treated at 65 ℃ for 30 min and stored for 8 d was significantly higher than in raw milk.This might be due to the bacterial proliferation.The content of CLA declined following temperature processing and storage whereas no significant difference was found(P 0.05).This study indicated that pasteurization had no effect on the contents of characteristic fatty acids in the milk.Therefore pasteurization could be used as an effective way to produce milk rich in CLA.