Extraction Of Lecthin By Enzymatic Hydrolysis Assisted And Catalytic Synthesis Of Phosphatidylserine

Phosphatidylserine has high nutritional value and can prevent many diseases.It is widely used in medical care,food processing and other industries.However,phosphatidylserine is very low in nature and difficult to extract from its sources.In this paper,duck egg yolk lecithin was extracted by protease at first,and then phosphatidylserine was synthesized by phosphatidylserine D catalysis.Finally,phosphatidylserine was separated and purified to obtain high purity phosphatidylserine.The main contents of this study are as follows:In this work,protease-assisted extraction of yolk lecithin from duck egg was studied.Single factor and orthogonal experiments were employed to optimize the extraction process,respectively.The effects of enzymatic dosage,ethanol concentration,material-liquid ratio,and extraction temperature on the extraction rate of lecithin were investigated.Infrared Spectroscopy(IR)was used to analyzed the properties of yolk lecithin.Protease-assisted extraction of yolk lecithin from duck egg was optimized with the amount of neutral protease added 0.2g/100 g egg yolk,95% ethanol concentration,extraction temperature 35?,and the ratio of material to liquid 1:5(g/mL).Under the optimal conditions,the yield of phospholipids was 84.47% containing phosphatidylcholine of 71.57%,which was detected using high performance liquid chromatography(HPLC).Phosphatidylserine was synthesized by phospholipase D catalyzed.The synthesis process was optimized by single factors and orthogonal experiments.The effects of pH,temperature,serine concentration and volume ratio of two phases on the yield of phosphatidylserine were investigated.The results showed that the optimum synthesis process was that the volume ratio of organic phase to inorganic phase was 10:1 in serine buffer solution of 0.14 g/ml,and the reaction time was 4 hours at pH 6.0 and 30 ?.The maximum yield of phosphatidylserine serine was 42.92%.Phosphatidylserine was separated and purified by column chromatography.The static adsorption properties of silica gel for phosphatidylserine were investigated.The binding properties of silica gel to phosphatidylserine were studied by kinetic adsorption equation and isothermal adsorption equation.The results showed that the purity and recovery of phosphatidylserine were 67.28% and 48.62% respectively.