Abstract: The volatile profiles and warmed-over flavor (WOF) of precooked pork patties reheated by microwave for different periods of time (0, 30, 60, 90, 120 and 180 s) were investigated to analyze the correlation among lipid oxidation, water distribution and WOF. The results showed that a total of 25 volatile compounds were identified using solid phase microextraction combined with gas chromatography-mass spectrometry, with aldehydes being predominant. Microwave reheating treatment for 30 s could accelerate lipid oxidation, and promote the formation of volatile flavors, especially WOF, but did not result in a significant change in the relaxation time and proportion of water in different states (P > 0.05). The content of WOF decreased with increasing reheating time up to 120–180 s, and the water content declined significantly (P < 0.05), together with a shift of T21 (bound water) and T22 (immobilized water) to a shorter relaxation time. Principal component analysis demonstrated that moderate microwave reheating (60–90 s) could play a critical role in inhibiting WOF and maintaining the flavor quality of precooked minced pork.

Key words: precooked minced pork, microwave reheating, warmed-over flavor, lipid oxidation, water distribution