Effects of phospholipids and reheating treatment on volatile compounds in phospholipid-xylose-cysteine reaction systems.

Volatile compound profiles in phospholipid (lecithin and cephalin)-xylose-cysteine reaction systems before and after reheating treatment were determined by solid phase micro-extraction combined with gas chromatography-mass spectrometry to investigate the development mechanism of the warmed-over flavor. The contents of sulfides in the four groups containing added lecithin were significantly higher than those in the other groups, indicating that lecithin had a strong promoting effect on the formation of Maillard reaction products at the intermediate-end stages in the reaction system. The coexistence of phosphatidylcholine and lecithin accelerated the Maillard reaction and fatty acid oxidation. Reheating treatment could promote the simultaneous generation of final-stage Maillard reaction products, the formation of fatty aldehydes, and the reaction of fatty aldehydes with intermediate-stage Maillard reaction products of the mid-stage, which ultimately leads to a decrease in the contents of sulfursulphur-containing Maillard reaction products such as those leading to aroma and an increase in the content of aldehydes in meat and demonstrated good consistency with the results of the sensory evaluation. Odour activity values showed that decanal was the main substance contributing to the warmed-over flavor after reheating treatment in the reaction system. The decrease in meaty flavors, such as 2-methylpentane-3-thiol and furfuryl mercaptan also resulted in flavor deterioration after reheating.