Effect of tannic acid-grafted chitosan coating on the quality of fresh pork slices during cold storage.

Tannic acid (TA)-chitosan (CH) conjugate (TA-g-CH) was prepared using a free radical grafting procedure to increase the antimicrobial and antioxidant performance of CH. The effect of TA-g-CH coating on the quality of fresh pork during 15 days of refrigerated storage was investigated. The pork samples were analyzed regularly for microbiological (total viable counts (TVC), Pseudomonas spp. and lactic acid bacteria (LAB)), physicochemical (pH, thiobarbituric acid-reactive substances (TBARS), protein oxidation and color) and sensory attributes. The results showed that both TA + CH and TA-g-CH coatings dramatically extended the shelf-life of pork slices by suppressing microbial proliferation and delaying lipid and protein oxidation. Specifically, the TA-g-CH coating exhibited the best performance on pork preservation, which can delay the quality deterioration of fresh meat by 3-6 days during cold storage. The study suggests that the TA-g-CH edible coating has considerable prospects for maintaining the storage quality of fresh meat.