Preparation Of Enzyme Modified Phospholipids And Study On Emulsification

Phospholipids are lipids containing phosphoric acid,which are natural Surfactant and have many functions such as emulsification,wetting,viscosity regulation,preventing resistant starch formation and promoting nutrient absorption,widely used in feed,food,medicine,chemical industry,leather,textile,cosmetics and other fields.Although phospholipids are good natural Surfactant,their application is limited because of their poor hydrophilicity and poor emulsifying ability.In order to reduce the production cost of phosphatides,it is necessary to further develop phosphatides with high hydrophilicity and emulsifying ability,which is also a hot topic in this field.The modification of phospholipids is to optimize the properties of ordinary phospholipids by physical,chemical or enzymatic methods.The modified phospholipids are better than ordinary phospholipids in emulsifying properties and stability,among which the enzyme modified phospholipids because it belongs to the natural substances in the organisms,so the use of high safety,wider application range,and the manufacturing process is mild,does not produce harmful substances,low production cost,so has more technical and commercial advantages.This paper aims to study the technology of preparing enzymatic modified soybean phospholipid concentrate by using PLA₂to hydrolyze and remove the fatty acids on the phospholipid molecules to obtain enzymatic hydrolyzed phospholipid.The results can provide the basis for the industrial production process of enzyme-modified phospholipids.The main research contents and results are as follows:The reaction conditions were optimized by single factor method.Independent variables such as initial p H、substrate concentration、temperature、enzyme addition、CaCl₂concentration,and time were taken as reaction variables,The reaction was optimized by measuring the conversion rate,and the preparation scheme of enzymatic modified phospholipids with a conversion rate of 61.33±1.24%was obtained.The change of fatty acid type and content before and after soybean concentrated phospholipase solution were analyzed using gas chromatography（flame ion detector）method.Sixteen fatty acid metabolites were detected in the sample and showed a significant increase in unsaturated fatty acids after enzymatic hydrolysis process,with linoleic acid（c18:2n6c）increased by 137.32 mg/g Lecithin,linolenic acid（c18:3n3）by29.31 mg/g Lecithin.The content of oleic acid（c18:1n9c）increased by 29.21 mg/g Lecithin,while the saturated fatty acid,including c06:0 and c08:0,did not change significantly before and after enzymatic lysis.The changes of phospholipids types and contents before and after enzymatic hydrolysis of soybean concentrated phospholipids were by lc-ms.Seven kinds of lipids were detected,among which diacylglycerol,monogalactosyl diacylglycerol and digalactosyl diacylglycerol had no obvious changes in the whole enzymatic hydrolysis process.The content of phosphatidylcholine and Phosphatidylethanolamine was reduced by 102.72μmol/g Lecithin and 148.27μmol/g Lecithin respectively,the content of lysophosphatidyl Choline and Lysophosphatidyl ethanolamine increased by 97.60μmol/g Lecithin and 135.59μmol/g Lecithin respectively.The analysis of the types and contents of free fatty acids and phospholipids showed that the sn-2 fatty acids of the main phospholipids hydrolyzed by PLA₂had high enzyme activity and high specificity.Compared with ordinary phospholipids,the content of unsaturated fatty acids in enzymatic modified phospholipids is lower and its stability is enhanced.The effects of free fatty acids,temperature,p H and inorganic salts on the emulsification ability of enzymatic modified phospholipids with different conversion rates were also studied.The results showed that a small amount of free fatty acids in phospholipid products had no adverse effect on the emulsification ability of phospholipid emulsion.The higher the concentration of CaCl₂,the worse the emulsifying ability.The effect of Na Cl on the emulsifying ability of phospholipid emulsion was not significant.Acid and high temperature conditions are not conducive to the stability of phospholipid emulsion.The emulsification ability of enzyme-modified phospholipids is better than that of ordinary phospholipids,and the higher the degree of enzyme-modified phospholipids,the better the emulsification ability.