Study On The Mechanism Of Alkyl Gallates Inhibit Glyoxal

Studies have shown that in the food processing,especially at medium to high temperature processing,the Maillard reaction produces partially detrimental products,such as 12-dicarbonyl compounds and advanced glycation end products(AGEs),which in vivo accumulation can lead to diabetes,Alzheimer’s disease and other diseases.This article focuses on the activity,reaction pathway and inhibition mechanism of the food additive gallic acid alkyl ester to remove the highly active Maillard reaction intermediate product glyoxal(GO).And verified in the cookie system.The main research is as follows:1.The inhibitory activity of gallic acid and gallic acid alkyl ester(PG,OG,DG)on GO was studied.The results showed that the inhibitory rates of three gallic acid alkyl esters on GO were over 51%,and PG,OG,DG and GO reaction system,an addition product of alkyl gallate and GO was synthesized and prepared.MG-PG,MG-OG and MG-DG were purified by ODS,TLC and other chromatographic techniques.Their structures were characterized by HPLC-MS/MS and nuclear magnetic resonance(NMR)MG-PG,MG-OG and MG-DG are formed by adding one molecule of GO to the C-2 position of PG,OG and DG.2.The functional activity of the adducts(MG-PG,MG-OG,MG-DG)was investigated with gallic acid alkyl ester as control.(1)MG-PG,MG-OG and MG-DG have good anti-oxidative properties.Alkalic acid alkyl ester adducts(MG-PG,MG-OG and MG-DG)Slightly lower than the same concentration of PG,OG,DG,but higher than Vc.The DPPH radical scavenging rate of MG-PG,MG-OG and MG-DG reached more than 85%when the concentration of DPPH radical was 500 μmol/L at room temperature.The effect of oil on lipid oxidation stability was evaluated by Rancimat method.The induction time of lard was 4 to 5 times longer than that of PG,OG and DG by MG-PG,MG-OG and MG-DG Much higher than BHT.(2)MG-PG,MG-OG and MG-DG had good anti-carbonyl free radical performance.In GO PBS system,the inhibition rate of GO reached 54.1%,47.8%and 39.9%respectively.During the heating process of oil,the inhibitory rates of GO,MG-OG and MG-DG reached 55.6,52.6 and 49.1%respectively,which were slightly lower than that of PG,OG and DG(58.1,57.3 and 54.9%respectively).In the Arg-glucose system,the inhibitory rates of GO produced by MG-PG,MG-OG and MG-DG at the concentration of 100 μmol/L were 43.2%,40.7%and 35.6%,respectively.In the 11S protein-glucose system,the inhibitory rates of GO on MG-PG,MG-OG and MG-DG were 47.1%,41.4%and 39.7%,respectively.At the same time more than three adducts of six substances on Arg-glucose and 11S protein-glucose system AGEs also have the same inhibitory effect.3.The reaction system of MG-PG,MG-OG,MG-DG and GO was constructed.The reaction products were analyzed by LC-MS/MS.The results showed that all three compounds could further capture GO formation of DG-PG,DG-OG and DG-DG,thus explaining that MG-PG,MG-OG and MG-DG have the mechanism of action to inhibit the follow-up effect of GO formation in different systems.Furthermore,LC-MS/MS analysis of the changes of PG,OG and DG in the cookie during processing sho wed that one of the adducts and the two adducts of PG,OG and DG with GO respectively.Thus,the pathways and mechanisms by which PG,OG and DG inhibit GO were validated.In addition,three kinds of gallic acid alkyl ester and three kinds of one adduct had certain inhibitory effect on the GO and AGEs produced in the actual system of cookie.At the dosage of 100 mg/kg,MG-PG,MG The inhibition rates of GO,GO and MG-DG on GO wre 37.7%,31.4%and 29.0%,respectively.The inhibitory activities of GO,OG and DG on GO were 44.5%,40.5%and 36.8%Adduct products were also found to have AGE-scavenging activity of 39.1%,31.6%,23.5%,respectively.