Volatile Organic Compounds Generated from the Maillard Reaction between l-Ascorbic Acid and Glycine in Hot Compressed Water

Abstract

The impact of pH and temperature on the volatile organic compounds (VOCs) produced from the Maillard reaction between l-ascorbic acid (ASA) and glycine (Gly) was investigated in hot compressed water (HCW) in the study. The results showed that VOCs generated from the reaction were mainly the derivatives of pyrazines, pyrroles, and pyridines. The effects of reaction temperature and pH on the generation of pyrazines, pyrroles, and pyridines were different. The higher temperature would promote the generation of pyrrole and pyridine derivatives, while the effect was not obvious to pyrazine derivatives. For some pyrrole derivatives, they were only detected under the reaction temperature of 210 °C. The pH of the solution would influence the types of VOC generation. According to the analysis of variance (ANOVA) and the p-value, it was found that the influences of pH on the formation of pyrazine derivatives were much more remarkably than those on generating pyrrole and pyridine derivatives. The alkaline reaction environment would promote the formation of nitrogen-containing heterocyclic VOCs. Based on the experimental results, the mechanism for the formation of pyrazine, pyrrole, and pyridine derivatives from the reaction of ASA with the Gly Maillard system was proposed in HCW.