Abstract: The volatile compounds of cooked minced pork with different water-bath reheating times (0, 5, 20, 35, and 65 min), were investigated by dynamic headspace combined with gas chromatography-olfactometry-mass spectrometry. A total of 54 volatile compounds were identified, with 36 of these being common to all samples. Aldehydes accounted for the highest proportion of the total volatile compounds in the samples heated for 5-20 min, and acid contents significantly increased after 35-65 min of reheating. The contents of pentanal, hexanal, octanal, and (E,E)-2,4-nonadienal were increased firstly and then decreased with increasing reheating time. 1-Octene-3-ol and 2-pentyl furan contents were not affected significantly by reheating time (P > 0.05). Odor activity value (OAV) analysis and principal component analysis (PCA) suggested that reheating had a significant effect on the flavor of cooked minced pork. The proportion of warmed-off flavor (WOF) in cooked minced pork was decreased slightly with reheating time, when using pentanal, hexanal, octanal and (E,E)-2,4-decadienal as WOF markers. Therefore, lipid oxidation may be the main formation pathway for reheating flavor in cooked minced pork, and WOF is more easily formed in a shorter reheating time.

Key words: cooked minced pork, reheating time, volatile compounds, warmed-off flavor