Abstract: Purpose: Non-enzymatic glycation reaction can be induced during the glycosylation modification of soybean 7S protein, which can give rise to the production of harmful advanced glycation end products (AGEs). In order to improve the safety of foods, soybean 7S protein-sugar system was established to find out the factors affecting the formation of AGEs and effectively control the glycosylation reaction under simulated food processing conditions. Methods: The influencing factors including sugar type, sugar concentration, pH, temperature, inhibitor type and inhibitor concentration were detected by fluorescence spectrometry (λex/λem = 340 nm/465 nm). The formation and inhibition of harmful products were characterized by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). Results: The use of fructose as a sugar, a ratio between sugar and protein concentrations of 1:4, a pH value of 9.2, and a reaction temperature of 121 ℃ were the best conditions for the formation of fluorescent AGEs. The flavonoids quercetin, genistein, rutin and luteolin could effectively and dose-dependently inhibit the formation of fluorescent AGEs. Conclusion: The types of sugar and inhibitor have a certain effect on the formation of fluorescent AGEs. We can inhibit the formation of fluorescent AGEs by reducing the ratio between sugar and protein concentrations, pH and reaction temperature as well as increasing the concentration of the inhibitor.

Key words: soybean 7S globulin-sugar system, glycosylation, fluorescent advanced glycation end products, fluorescence spectrometry, sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE)