Effects Of Sugar Structure On The Formation Of Advanced Glycation End Products In Model Systems

Advanced glycation end products(AGEs)are products of a nonenzymatic reaction between the carbonyl group of reducing sugars and the free amino group of proteins,peptides or amino acids.The formation of AGEs is affected by food formulation and processing conditions.Sugar is a common ingredient in food processing,and there are many types of sugar.However,the effect of sugar on the formation of AGEs is still not clear.Therefore,the effects of structure and type of sugar on the formation of AGEs in the sugar-lysine system were studied under different reaction temperatures(80°C~120°C)and time(20~120 min)First,the LC-MS/MS method was established for determination of three AGEs(N?-(Carboxymethyl)lysine,CML;N?-(Carboxyethyl)lysine,CEL;Pyrraline,Pyr),and another method was also established for determination of three ?-dicarbonyl compounds(Glyoxal,GO;Methylglyoxal,MGO;3-deoxyglucosone,3-DG).The monosaccharide-lysine systems were developed to compare the effects of two aldoses(glucose and galactose)and two ketoses(fructose and sorbose)on the formation of AGEs.The results showed that the degree of lysine loss,color increase and pH decrease in the aldose systems were higher than that in the ketose systems.Therefore,the aldose systems were more prone to the Maillard reaction.For AGEs intermediates,the aldose systems were more prone to form 3-DG and fructosylysine(FL),while the ketose systems were more prone to form MGO.The ?-dicarbonyl compounds were formed largely within the first 20 min,but the FL formation was suppressed at 120°C.At 120°C,the content of CML and CEL in ketose systems was higher than that in aldose systems,which was the opposite of the result at 80°C.The content of Pyr was much lower than that of CML and CEL.The AGEs were mainly formed by ?-dicarbonyl compounds pathway at 120°C.The disaccharide-lysine systems were developed to compare the effects of three common disaccharides(sucrose,maltose,and lactose)on the formation of AGEs.The effect of disaccharide on the degree of Maillard reaction was lactose>maltose>sucrose.For AGEs intermediates,the lactose system was more prone to produce GO and MGO,while the sucrose and maltose systems were more prone to 3-DG.The content of FL in the maltose system was higher than that in the sucrose and lactose systems.The lactose system was more prone to form CML and CEL.At 80°C,the level of FL content was much higher than that of ?-dicarbonyl compounds,which indicated that the AGEs were mainly formed by the FL pathway.At 120°C,the AGEs were mainly formed by FL and ?-dicarbonyl compounds pathway.The maltodextrin-lysine systems were developed to compare the effects of four different dextrose equivalent(DE)values of maltodextrin on the formation of AGEs.The degree of Maillard reaction of the system was increased as the increase of DE value.The content of three AGEs and four intermediates of AGEs were increased with the increase of DE value.The level of FL content was much lower than that of ?-dicarbonyl compounds,which indicated that the AGEs were mainly formation by ?-dicarbonyl compounds pathway.In addition,the level of AGEs formation of all maltodextrin-lysine systems was much lower than those of monosaccharide and disaccharide systems.Based on different formula levels and processing conditions,the effects of structure and type of sugar on the formation of AGEs were studied.It is important for reducing the content of AGEs in food systems and improving food safety in the future.