Comparison of Lipids in Four Kinds of Milk Powder of Cow and Goat

Objective: To compare and analyze the lipid characteristics of common and organic milk powder. Methods: Taking common milk powder, common goat milk powder, organic milk powder and organic goat milk powder as research objects, lipids in milk powder were extracted by chloroform methanol method, triglyceride and phospholipid were separated by aminopropyl silica gel solid phase extraction column, Sn-2 monoglyceride was obtained by hydrolyzing 1,3-fatty acid of triglyceride molecule with porcine pancreatic lipase, and Sn-2 fatty acid was obtained by hydrolyzing phospholipid with phospholipase A₂. The composition and content of triglycerides and phospholipids were analyzed by gas chromatography, the configuration of triglycerides was analyzed by ultra-high performance liquid chromatography coupled with mass spectrometry, and the composition and content of phospholipids and cholesterol were determined by high performance liquid chromatography. Results: The contents of lipid, triglyceride and phospholipid in goat milk powder were higher than those in cow milk powder, and the content of common milk powder was higher than that of organic milk powder. Palmitic acid was the main saturated fatty acid and oleic acid was the main monounsaturated fatty acid in milk powder, and the content of common goat milk powder was significantly higher than the other three kinds of milk powder(P<0.05). The content of n-6 series polyunsaturated fatty acids in ordinary goat milk powder was the highest, and the content of n-3 series polyunsaturated fatty acids in organic goat milk powder was the highest. The four kinds of milk powder Sn-2 fatty acids were mainly saturated fatty acids, and lauric acid, myristic acid and palmitic acid were more likely to be distributed in the Sn-2 position of triglycerides, and palmitic acid was also more likely to be distributed in the Sn-2 position of phospholipids. The medium chain triglycerides(MCT) of four kinds of milk powder were mainly composed of Ca-Ca-Ca(Ca:C_10:0) and Ca-Ca-La(La:C_12:0), and the MCT of goat milk powder was higher than that of cow milk powder. The contents of medium and long chain triglycerides(MLCT) in goat milk powder were higher than those in cow milk powder(P: C_16:0), Ca-Ca-O(O:C_18:0) and la-m-p (M:C_14:0) (P<0.05). The highest content of LCT was O-P-O(O:C_18:0). Conclusions: The lipid of goat milk powder was more easily absorbed than that of cow milk powder. Compared with ordinary milk powder, organic milk powder had more security, higher n-3 PUFA content and higher nutritional value.