Regulation Of Maillard Harmful Products In Gluten Glycosylation Modification And Baking Processing

Wheat gluten plays a critical rolein the processing of flour products and imposes great effect on structuretaste and color of products.However,the poor solubility of wheat gluten limits its application in food as a food ingredient.The functionality of protein could be modified by glycation reaction which is a commonly used processing approach.However,some detrimental substances such as 1,2-dicarbonyl compounds(glyoxal,methylglyoxal,etc.)and advanced glycation end products(AGEs)were inevitably produced by the Maillard reaction between wheat gluten and sugar in the processing of flour products and glycosylated modification.These substances can cause chronic diseases such as diabetes and aging.In this paper,the system of gliadin-dextran and glutenin-dextran were established to simulate the system of glycosylated modification,and the gluten-glucose system was established to simulate the system of baking.The effects of different factors on the formation of MGO/GO/AGEs in these syetem were studied.According to the investigation of MGO/GO/AGEs-inhibiting efficacy of different natural products,the inhibition mechanism was studied using HPLC-MS/MS.Thus providing a theoretical basis for the safety of food processing and production.1.The effect of sugar(monosaccharides,disaccharides,polysaccharides),dextran concentration,modified temperature,time and natural inhibitors on the formation of MGO/GO/AGEs in the system were studied.In the two protein systems,the harmful products produced during the glycosylation of glutenin were higher than those of the gliadin.The amount of various harmful products produced by the monosaccharide was much higher than that of the polysaccharide,especially the amount of MGO was much higher than GO.Futhermore,the formation of MGO/GO and AGEs stably increased along with the elevation of dextran concentration,temperature and time in the two wheat protein systems.In alkaline gliadin-dextran modified system,the instability of catechins,quercetin,rutin,genistein,ferulic acid,chlorogenic acid,emodin,capsaicin led to their poor inhibitory efficacy.But the inhibitory rate of cysteine on MGO and AGEs can reach more than 70%,and the emulsification of modified protein is still improved.2.The effects of processing conditions(time and temperature),reaction substrate(sugar type,sugar concentration,gluten content),additives(salt,baking powder,tartan powder),main ingredients(starch,protein,oil)and inhibitors on the formation of MGO/GO/AGEs were studied in the gluten-glucose system.The formation of MGO/GO/AGEs was positively correlated with time,temperature,sugar concentration and pH,and the amount of MGO was greater than GO.From 15 min to 20 min,the increase of MGO and fluorescence AGEs was significant.The the amount of the three harmful products increased with the increase of different temperatures(160,180,200?).Pentose(arabinose and xylose)produced more GO and fluorescent AGEs than hexose(fructose and glucose),while fructose produced the largest amount of MGO.Three kinds of harmful products produced by hexose are more than disaccharide(maltose,sucrose).The formation of MGO/GO/AGEs was negatively correlated with the addition of additives(salt,baking powder,tartan powder),but the addition of main ingredients(starch,ovalbumin and corn oil)had little effect on the formation of harmful products MGO/GO/AGEs.Capsaicin(alkaloid),quercetin(flavone),PG(polyphenol)and ferulic acid(phenolic acid)were separately mixed with luteolin(flavonoids)and these mixtures were dividually added into wheat gluten-glucose system.The results clearly indicated that different inhibitors could additively inhibit MGO/GO/AGEs.In particular,PG and luteolin showed synergistic effect.3.The products of luteolin,PG,quercetin,capsaicin,luteolin-PG,luteolin-quercetin and luteolin-capsaicin with MGO/GO were analyzed by LC-MS/MS to study the mechanism of inhibition.The results showed that there were similar mechanisms in the three systems:the activity and the pathways of the complex system were maintained in the single system.1,Inhibitors captured MGO to form the additive products MM and DM;2,Forming quinone indicated that the adduct product has antioxidant activity and can continue to play a follow-up effect in the system.In the complex system of luteolin and PG,luteolin inhibited MGO/GO through two pathways.One is that luteolin trapped MGO and formed the additive products MM-L(1)and DM-L(3).Another is that MGO adducts of luteolin continued to conduct antioxidant activity and dehydrogenated to form quinone MMQ-L(1),DMQ-L(1)to inhibit formation of MGO/GO and AGEs.At the same time,PG trapped MGO and GO and formed MG-P and MG-P respectively so as to reduce the formation of MGO/GO.The species of the complex system was consistent with that of the use alone.In contrast to the system of luteolin-MGO/GO,PG enhanced the conversion of luteolin products and acted synergistically in the complex system of luteolin and PG.In the luteolin and capsaicin complex system,the species of the adduct product in the complex system was consistent with that of the use alone.but capsaicin had no change under low temperature condition.The adduct product of capsaicin was formed under high temperature condition,resulting in active superposition effect.In the complex system of luteolin and quercetin,both flavonoids can form adduct MM-L-1(1),DM-L-1(1)and DM-Q-1(1 species)to reduce the amount of MGO in the system;secondly,MGO adducts of two flavonoids can continue to developed antioxidant activity and form quinone DMQ-L(3)and DMQ-Q(1)to inhibit the formation of MGO/GO.The two flavonoids were used alone,and the reaction of luteolin and quercetin was promoted.The reaction of luteolin and quercetin with MGO was accelerated and additively inhibited MGO/GO in the complex system of luteolin and quercetin.