Study On The Texture Properties And Oxidation Characteristics Of Egg Yolk Powder Gel

In eggs,egg yolk accounts for 28%-29%,Egg yolk contains egg yolk lecithin,low density lipoprotein,high density lipoprotein,Phosvitin,cholesterol and other biologically active substances.Therefore,egg yolk has high nutrients and various functional properties(such as gelatinous and emulsibility).Egg yolk processed into egg yolk powder,it will not affect functional characteristics and can be eaten more conveniently and safely.Egg yolk has more proteome components and therefor has good gel properties.Adding gel properties to foods is a good application effect.In this study,egg yolk powder was used as raw material to study the heat-induced gel formation of egg yolk powder and its gel properties.The lipid component of the egg yolk powder gel was examined and compared with the lipid component of the egg yolk powder.On the basis of determining the lipid component of egg yolk powder gel,the oxidation characteristics of egg yolk powder gel.The main research results are as follows:(1)Investigate factors such as water addition,NaCl content,heating temperature and heating time in the preparation of egg yolk powder gel.The optimal conditions are egg yolk powder with 150%deionized water,3%sodium chloride,after 10min stirring with a magnetic stirrer,15min heat treatment at a temperature of 100 0C.(2)The analysis of the texture characteristics(hardness,elasticity,adhesion,cohesiveness,chewiness and recovery)of the formed egg yolk powder showed that the effect of water addition on the texture characteristics of egg yolk powder gel and its correlation Sexual analysis showed a significant positive correlation between gel strength,hardness and chewiness(p<0.01),a significant negative correlation with elasticity(p<0.01),and a significant negative correlation with adhesion(p<0.05),positively correlated with cohesiveness and recovery.The effect of sodium chloride concentration on the texture properties of egg yolk powder gel and correlation analysis showed that there was no significant correlation between gel strength and other texture properties,and negative correlation with elasticity and recovery,hardness and adhesion.,cohesiveness,etc.are positively correlated.The effect of heating temperature on the texture properties of egg yolk powder gel and the correlation analysis showed that the gel strength was significantly positively correlated with hardness,adhesion and chewiness(p<0.01),and elasticity and cohesion.Negatively correlated with resilience.The effect of heating time on the texture characteristics of egg yolk powder gel and correlation analysis showed that the gel strength was significantly positively correlated with hardness,adhesion and viscous chewability(p<0.01),and the recovery was extremely significant.Negative correlation(p<0.01)was positively correlated with elasticity and negatively correlated with cohesion.(3)The lipid components of egg yolk powder gel were analyzed by gas chromatography and nuclear magnetic resonance(31P-NMR),and 19 fatty acids,three phospholipid components(PC,PE,PI)and cholesterol were detected,which were the same as the lipid composition of egg yolk powder.The preparation of egg yolk powder gel process reduced lipid content,and there was a significant difference between cholesterol content and monounsaturated fatty acid content(p<0.01).There was significant difference in polyunsaturated fatty acid content(P<0.05),polyunsaturated fatty acid.There were no significant differences in phospholipid components.(4)During the accelerated oxidation of the schaal oven,the fatty acid content of the egg yolk powder gel tends to decrease,and various fatty acids are significantly reduced during the 2-6 days of oxidation(p<0.05).Cholesterol content also decreases faster during 2-6 days.The content of phosphatidylcholine(PC)and phosphatidylethanolamine(PE)in the phospholipid fraction of egg yolk powder was significantly reduced(p<0.05),and the content of phosphatidylinositol(PI)was not significantly changed.The peroxide value of egg yolk powder gel increased significantly with the increase of storage time(p<0.05)and the high-measurement resveratrol sample had better oxidation stability;Nuclear magnetic resonance spectroscopy confirmed that the primary oxidation product produced by the egg yolk powder gel had a chemical shift of conjugated peroxide of 5.7 ppm(conjugated form)and a chemical shift of secondary oxidation product(n-alkanal)of 9.75 ppm.