Study on the volatile compounds generated from lipid oxidation of Chinese bacon (unsmoked) during processing

In order to investigate the generation of aroma in Chinese bacon (unsmoked), the changes of lipolysis, lipid oxidation, and volatile compounds derived from lipid oxidation (VCDFLO) during processing were analyzed. The results showed that acid lipase activity decreased during the entire process, while neutral lipase and lipoxygenase (LOX) increased from raw meat to the 1 day of dry-ripening then decreased. Phospholipase increased during dry-curing then decreased during dry-ripening. Thiobarbituric acid reactive substances increased from raw meat to the 7 days of dry-ripening thereafter decreased. Total free fatty acids increased at the end of 1 day of dry-ripening and decreased subsequently. Thirty-five VCDFLO were identified; the total peak area of these compounds increased by almost double at the 4 days of dry-ripening than raw meat and indicated 47.37-50.85% of total 78 volatile compounds in the final products. In conclusion, VCDFLO generation was attributed to lipid-related enzymes and contributed mainly to the aroma. Practical applications: Chinese bacon (unsmoked) usually produced from high intramuscular fat pork has more intense and long-lasting aroma, since intramuscular triglycerides are good precursors for most volatile compounds. Understanding the mechanism of aroma formation related to lipid oxidation could help us to improve the product quality and optimize the duration of processing. Therefore, the present work identified the characteristic flavor compounds and provided the changing regularity of these compounds at various stages to facilitate the generation of them by regulating lipases and lipoxygenase (LOX) activities. The work showed that neutral lipase and lipoxygenase (LOX) played important roles during dry-curing and dry-ripening. The regulation of lipases and LOX activities can facilitate the generation of volatile compounds of Chinese bacon (unsmoked).