Optimization of Extraction Process and Composition Identification of Polar Lipids in Milk

In order to develop and utilize the milk polar lipids, the chloroform-methanol extraction method was used to extract the polar lipids from buttermilk. The phosphorus content as an index, the condition of chloroform-methanol volume ratio, liquid-to-methanol ratio, extraction temperature and time were optimized by single-factor experiment and the analysis of response surface methodology determined the optimum extraction conditions. The obtained samples were analyzed and identified by thin-layer chromatography(TLC). The results indicated that the optimal extraction conditions for polar lipids were: Chloroform-methanol volume ratio 2:1(v/v, %), 1:4(v/v, %) for the ratio of material to liquid, 20 ℃ for extraction temperature, and 10 min for extraction time. The phospholipid contents in the sample under this extracted condition was (1.647±0.010) mg/g, and there were polar lipids such as phosphatidylcholine, phosphatidylethanolamine, phosphatidylserine, and sphingomyelin. This process aims to provide a research basis for the extraction and development of milk polar lipids.