Changes in aroma components and potential Maillard reaction products during the stir-frying of pork slices

Stir-fried pork slices are kinds of traditional pork processing products in China, which are usually cooked at high temperature with different seasonings. Because of their special quality and flavor, these products gain consumers' preference. However, there are few studies on their physicochemical properties, aroma composition and safety. In this study, the changes in basic components, aroma components and potentially hazardous substances during the stir-frying of pork slices were determined. The effects of the different ratios of fat meat to lean meat and vinegar on these indicators were evaluated, and the formation of potential Maillard reaction products was also analyzed. The results indicated that water content, chrominance values of L* and b* exhibited decreasing trends; a* value displayed a trend of decline first and then rising, while the fat content showed a rising trend during the processing. Appropriate stir-frying can promote the formation of aldehydes, while the content of acids, ketones, and terpenes decreased during processing. The change of alcohols has no obvious rule. Some sulfur compounds not found in raw meat were also detected. Different ratios of fat meat and lean meat changed the kinds of aroma components, while vinegar altered the types and their contents. Besides, the contents of acrylamide and 5-HMF changed significantly, and that of benzo(a)pyrene remained at a low level. The addition of vinegar can enhance the amount of acrylamide and 5-HMF but has no obvious effect on benzo(a)pyrene. Besides, 8 kinds of Maillard reaction products (acrylamide, 5-HMF, benzo(a)pyrene, 5-methylfurfural, pyrazine, 4-methylimidazole, pyrraline, and 5- hydroxymethyl - 2-furancarboxylic acid) were determined, and some of them were harmful to product quality and human health. The results showed that the processing time of pork slices should be controlled within 60 min.