Lei Zang¹, Xinping Jin¹, Xiaopei Liu¹, Dongdong Wang¹, Ying Xu¹, Shanshan Li¹, Nan Xue¹, Rongrong Liang², Huawen Zhang³, Hailian Wang³, Shubing Liu¹, Yuye Wu^1,

As one of the favorite foods, lipid oxidation of pork meat has always been a problem faced by meat industry. Meat producers typically add synthetic antioxidants to mitigate lipid oxidation in pork. With the growth of health awareness and pursuit of natural products in recent years, there is a growing demand to develop natural antioxidants. The aim of this work was to extract tannins from sorghum grain and theninvestigate its effect on lipid oxidation of chilled pork. The tannins extracted from sorghum grain contained three monomers (15.17 mg/g for catechin, 9.74 mg/g for epicatechin and 17.2 mg/g for epicatechin gallate, individually) and exhibited higher antioxidant capacity than rutin in vitro. The addition of 0.2% tannin on pork meat significantly inhibited the increase of pH value, TBA value, TVB-N and total number of colonies (by 2.4%, 64%, 35%, 7.5%, respectively) and maintained the desired red color of chilled pork during refrigerated storage of 10 days. The antioxidant effect of 0.2% tannin treatment was better than that of BHT. Further, higher sensory scores were observed for the tannin-incorporated samples. The addition of 0.2% tannin significantly inhibited the lipid oxidation of pork, slowed down the meat color change, and prolonged the shelf life of pork while maintaining the sensorial characteristics intact. This study indicates the feasibility of sorghum tannin as a natural antioxidant for pork preservation, further boosting the commercial value of sorghum.

sorghum tannin, natural antioxidant, meat preservation, lipid oxidation