Conversion of Glucose-Glycine Amadori Compound to 2-Furfural Induced by Glyoxal

2-Furfural is a potential genotoxic compound that could be generated through the Maillard reaction. Clarification of reaction pathways affecting the 2-furfural formation shows great significance. 2-Furfural formation from the glucose-glycine Amadori compound (AC) was found to be greatly influenced by the intermediate glyoxal. 2-Furfural tended to be formed at neutral or slightly alkaline pH levels, but its yield was elevated with the involvement of glyoxal. With the increase in glyoxal dosage, 2-furfural formation was promoted. However, pyrazine concentration was reduced by about 50% as the glyoxal dosage increased, and methylpyrazine was not detected regardless of glyoxal dosage. The content of free glycine was also decreased with the additional glyoxal involvement in the reaction, indicating an ineffective formation of pyrazines from glycine generation and Strecker degradation. When the molar ratio of glyoxal to AC was increased to 1:1, deoxyglucosone conversion to short-chain α-dicarbonyls was inhibited. The adducts formed between one molecule of AC and one or two molecules of glyoxal were observed in the products when the glyoxal dosage increased. The degradation of glyoxal-AC adducts could probably effectively convert into 2-furfural but block the yield of pyrazine.