Promoting lipid oxidation and release of volatiles of pork fat pulp by lipase, blue light with riboflavin in liquor immersion

Abstract

The deeply oxidized pork fat (PF) is the key in the production of Chi-aroma Baijiu, a Chinese distilled spirit. Previous studies have not proposed an integrated method to promote lipid oxidation of PF, and the formation of volatiles has not been studied. In this work, an efficient method was established to promote lipid oxidation and release of volatiles of pork fat pulp (PFP) in an integrated treatment for the production of Chi-aroma Baijiu. The results showed that the acid value of PFP by lipase pretreatment (T1) was significantly elevated (p < 0.05), compared to the control (T0). Lipase-blue light-riboflavin-25°C (T2), lipase-open vial-dark-25°C (T3), and lipase-dark-40°C (T4) further promoted lipid oxidation and reached the oxidation level of PFP by F0, while T2 show the best results. The peroxide value of PFP by T2, T3, and T4 was 41.96-, 16.70- and 14.20-fold higher, and the para-anisidine value was 27.13-, 6.94- and 6.70 fold higher than that in T1. The flavor and volatile analyses showed that PFP by T2 had higher response values than T0 at six electronic nose sensors. T2-T4 promoted the release of volatiles and T2 showed the best result. T2 potentially facilitated lipid oxidation, esterification, and substance exchange of PFP, resulting in a higher type (78.57%) and content (114.50%) of volatiles than T0. The integrated treatment with lipase hydrolysis, blue light with riboflavin could promote lipid oxidation and volatiles release to improve production efficiency of deeply oxidized PF. The results would be viably applied to the production of Chi-aroma Baijiu. PRACTICAL APPLICATION: Deeply oxidized pork fat was the key to the production of Chi-aroma Baijiu, while it took a long time (at least 4 months) to prepare. The integrated treatment with lipase hydrolysis, blue light with riboflavin could promote lipid oxidation and volatiles release to improve the production efficiency of deeply oxidized pork fat. The results would be viably applied to the production of Chi-aroma Baijiu.

Keywords: blue light with riboflavin; distilled spirit; lipase; lipid oxidation; pork fat.