Effects Of Different Saturated Fatty Acids On Glycosylation Model System

Different fatty acids have different effects on glycosylation reaction.Based on the establishment of Maillard reaction system of D-glucose and L-lysine,different saturated fatty acids(oleic acid,linoleic acid,EPA,palm oil)-containing systems were used to compare the production of GLY1,GLY2,GLY3,GLY4 and Maillard’s non-fat system(GL).The production and processing of normal food were simulated at 100℃ for 40 h.The contents of intermediate products glyoxal(GO),methylglyoxal(MGO),the final product carboxymethyllysine(CML),pentosidine,and fluorescent AGEs were analyzed.The final products of pentosidine and fluorescent AGEs were analyzed by fluorescence,the CML was analyzed by liquid chromatography-mass spectrometry to investigate the effect of various lipids on the glycosylation systems.Next,the Maillard-containing lipid system(GLY)represented by oleic acid was heated at different temperatures(60℃,80℃,100℃,120℃)40 hours or 2 hours,respectively.By analyzing the contents of GO,MGO,pentosidine,fluorescent AGEs and CML to explore the effects of oils on glycosylation at different temperatures.Finally,we established a lipid-containing Maillard system containing [13C6]-glucose and normal glucose at a molar ratio of 1:1 and no lipid-containing Maillard system,using labeled CML and non-labeled CML as indicators to explore the percentage of different fatty acids involved in the Maillard reaction.The main findings are as follows:1.By changing the reaction system substrate concentration and reaction temperature,the optimal reaction concentration of each substrate was determined to be 0.05 mol/L,the molar ratio was 1:1:1,the reaction temperature was 100℃,and the reaction time was 40 h.2.The presence of oil promotes the formation of dicarbonyl compounds.The higher the degree of unsaturation is,the more obvious the effect is.The GO content of all lipid-containing systems was significantly higher than the Maillard system.The palm oil with the highest saturation had no obvious effect on the formation of pentosidine.As the degree of unsaturation increased,all oils had a significant effect on pentosidine(p<0.01).The effect of different fatty acids on the fluorescence AGEs was small,and the amount of fluorescent AGEs produced by the GL system was slightly higher than the lipid-containing system(p<0.01).The content of CML produced in GLY4 system is higher than GLY1 and GLY2,indicating that in the reaction stage,the main reaction is unsaturated fatty acid.However,with the prolongation of reaction time,the amount of CML produced in GLY4 system is higher than that produced by GLY1 and GLY2.The lower amount of CML indicates that with the consumption of unsaturated fatty acids,the increase in the proportion of saturated fatty acids inhibits the reaction.4.The content of MGO in GLY system was significantly higher than that in GL system(p<0.01).In the GLY and Y systems,MGO drops first,then rises,then falls,finally stabilizes.The reason is that MGO itself is not stable.It was initially decomposed rapidly due to heat,and then it rose due to increased oxidation of diglycerides.The GO concentration of GLY system and GL system showed a gradual increase,and the GO concentration of GLY system was higher than GL system(p<0.05).It indicates that the presence of oil promoted the formation of dicarbonyl compounds.The pentosans in the GLY system are slightly higher than those in the GL system because the presence of carbonyls contributes to the formation of pentosidines.In the GLY and GL systems,high temperature promotes the increase of pentosidine content,and long-term high temperature accelerates its decomposition.The content of fluorescent AGEs in GLY system was higher than GL system(p<0.05),which indicates that the presence of lipids promoted the production of AGEs.In the same system,different temperatures had a great influence on the production of AGEs(p<0.01).The higher the temperature,the more Maillard reaction is promoted.CML increases gradually with reaction time.The higher temperature is in the same reaction time,the higher amount of CML generated.4.The proportions of oleic acid,linoleic acid,EPA,and palm oil fatty acids involved in the formation of CML were 23%,25%,20%,and 16%,respectively.The amount of CML generated in different GLY systems is 27%,23%,20%,and 52% less than that of the GL system.The participation ratios of oleic acid at 8h,16 h,24h,32 h,and 40 h were 2.2%,4.6%,7.1%,8.3%,and 2.0%;The proportions of linoleic acid participating in 8h,16 h,24h,32 h,40h were 2.9%,4.3%,9.3%,6.5%,2.0%;The proportion of EPA participating in 8h,16 h,24h,32 h,40h was 4.9%,3.2%,2.8%,2.5%,2.1%;The proportions of palm oil participating in 8h,16 h,24h,32 h,40h were 2.6%,2.9%,2.8%,2.6%,2.5%.