Abstract: The volatile flavor components of cooked pig ear reheated by different methods (pasteurization, steaming, microwave and high temperature) were investigated by purge and trap-thermal desorption combined with gas chromatography-mass spectrometry. Thiobarbituric acid reactive substance (TBARS) value was used as an indicator to evaluate the degree of lipid oxidation. The results showed that a total of 58 flavor substances were identified in all reheated samples, the predominant ones being aldehydes and hydrocarbons. Hexanal, octanal, nonanal, decanal, (E)-2-decenal, (E,E)-2,4-decadienal, 1-octen-3-ol, phenol and eugenol contributed greater to the flavor of reheated pig ear based on their odor activity value (OAV). Principal component analysis (PCA) revealed that steam heating did not significantly change the flavor of cooked pig ear. The warmed-over flavor (WOF) profile of reheated cooked pig ear was dominated by linseed oil-like flavor with slighter metallic and rancid flavor. Pasteurization reheating significantly increased the contents of the key flavor factors responsible for WOF and TBARS value, while microwave heating avoided WOF formation better than other methods.

Key words: cooked pig ear, reheating, volatile flavor, lipid oxidation, warmed-over flavor