Study On The Preparation Of Modified Phospholipids Catalyzed By Lipase

Phospholipids are important component of the structure of biological membranes,and their structure and composition have significant effects on the various biological activities of cells.At the same time,different fatty acid molecules have different physiological functions.Among them,n-3 polyunsaturated fatty acids(n-3 PUFAs)have the effects of anti-inflammatory,promoting brain development,and alleviating cardiovascular diseases.The ratio of n-6/n-3 PUFAs has a certain correlation with chronic diseases and cancer.The Chinese Nutrition Society stated in the "Reference Intake of Dietary Nutrients for Chinese Residents" that the appropriate intake ratio of n-6/n-3 PUFAs in the diet is 4:1-6:1.The ratio of n-6/n-3 PUFAs of natural phospholipids(such as soybean phospholipids)is too high,which does not meet the requirements of health standards.In addition,the emulsifying properties of natural phospholipids need to be improved.Therefore,this paper uses lipase to catalyze the transesterification reaction between natural phospholipids and vegetable oils to adjust the ratio of n-6/n-3 PUFAs in natural phospholipids to prepare modified phospholipids and lysophospholipids with better emulsification properties.1.The ratio of n-6/n-3 fatty acids in soybean phosphatidylcholine(PC)is adjusted by using rubber seed oil(RSO)with a ratio of n-6/n-3 of 2:1 as a substrate.The optimal reaction conditions are:PC/RSO mass ratio 1/5,Lipozyme 40086 lipase dosage 20%wt,water addition 1%wt,45℃.After 3 hours of reaction,the PC content was 55.19%,and the ratio of n-6/n-3 PUFAs in PC decreased from 13 to 6.44.2.Perilla seed oil(PSO)with a ratio of n-6/n-3 of 0.2:1 was used as a substrate to adjust the ratio of fatty acids n-6/n-3 of soybean PC.The catalytic reaction conditions were optimized by response surface analysis.The optimal reaction conditions were:PC/PSO mass ratio 1/5,Lipozyme 40086 lipase dosage 19.6%wt,water addition 1.27%wt,44.5℃.After 12 hours of reaction,the content of PC was 57.87%,the content of n-3 PUFA in PC was 24.78%,and the ratio of n-6/n-3 PUFAs decreased from 13 to 1.49.3.Based on the above research,the ratio of n-6/n-3 PUFAs in PC has not yet fully met the 4:1～6:1 standard recommended by the Chinese Nutrition Society.Therefore,the method of using the compound reaction of RSO and PSO to adjust the ratio of n-6/n-3 fatty acids in soybean PC was explored.The optimal compound ratio RSO/PSO is 3/1,and other reaction conditions are the same as the RSO system.After 3 hours of reaction,the PC content was 60.77%,and the ratio of n-6/n-3 PUFAs decreased from 13 to 4.37,which reached the standard recommended by the Chinese Nutrition Society.Under optimal conditions,Lipozyme 40086 can be reused five times.4.Aiming at the problem that the emulsification properties of natural phospholipids need to be improved,lysophospholipids(LPC)were prepared by hydrolyzing soybean phospholipids(PC)by lipase.The reaction conditions are:PC is 3 g,Novozyme 435 lipase dosage is 30%wt,water added is 20%wt,55℃.After 24 hours of reaction,the product yield was 84.5%.The content of PC in the product phospholipid is only 9.61%,glycerol phosphorylcholine(GPC)is 33.11%,and LPC is 57.28%.The experiment of using phospholipids as emulsifiers to emulsify soybean oil and water proves that the emulsifying properties of lysophospholipids are better than soybean phospholipids,and their acid and alkali resistance,high temperature resistance and salt resistance are stronger,and they have better application prospects.