Formation mechanism of aroma compounds in a glutathione-glucose reaction with fat or oxidized fat.

Glutathione and glucose with or without chicken fat/oxidized chicken fat were thermally reacted for generation of stewed meat-like aroma, where 42 sulfur-containing odorants were identified by gas chromatography-mass spectrometry (GC-MS) and gas chromatography-olfactometry (GC-O). The observed effects or interactions on meat flavor formation due to the fats were similar to previous reports of cysteine-reducing sugar reactions. Carbohydrate module labeling approach demonstrated ten alkyl chain compounds were indeed resulted from the lipid degradation-Maillard reaction interactions, whereas the fats had little effect on formation pathways of compounds only derived from the Maillard reaction. Formation pathways of 26 potent aroma compounds were proposed, particularly, involving two benzene derivatives and seven complex thiophenes. Notably, it was found for the first time just 2-ethylthiophene could result from both an intact skeleton of glucose and the lipid degradation product of 2,4-hexadienal, and the carbohydrate modules methylglyoxal and hydroxyacetone could arise from the glutamic acid of GSH.