Effects of heat treatments, storage and reheating on volatile compounds in pork and screening for characteristic volatile compounds

Precooked pork products subjected to different heat treatments (boiling, frying, and roasting; until reaching 75 °C of internal temperature) were used to evaluate the changes in volatile compounds of these products during their later storage (0 °C, 0–14 d) and reheating. The volatile compounds were collected simultaneously with the reheating of the precooked pork. The extent of oxidation in precooked pork increased during the storage, and the roasted pork had the highest degree of oxidation, with the mean levels of thiobarbituric acid reactive substances ranging from 3.41 to 7.70 mg malondialdehyde/kg and carbonyl values from 1.65 to 4.85 nmol/mg protein, respectively. Ten characteristic volatile compounds including 5 aldehydes, 3 alcohols and 2 alkanes were selected as indicators for quality deterioration of precooked pork during storage and reheating. All 10 volatile compounds were positively correlated with lipid oxidation (r = 0.912–0.966) and protein oxidation (r = 0.854–0.948), while the formation of 8 selected aldehydes or alcohols could be deduced from the autoxidation of unsaturated fatty acids of pork fat.