Effects of chitosan-based coatings incorporated with e-polylysine and ascorbic acid on the shelf-life of pork

Chitosan is a food thickener with film-forming ability and antibacterial activity. e-Polylysine is a preservative with broad-spectrum antibacterial activity. Ascorbic acid is a food antioxidant. In this study, pork chunks were treated with four dipping solutions, i.e. purified water (control), 0.2% ascorbic acid (treatment-1), 0.02% e-polylysine (treatment-2), and 0.4% chitosan + 0.02% e-polylysine + 0.2% ascorbic acid (treatment-3), and stored at 3 degrees C for 12 days. All treatments suppressed bacterial growth, increases in pH and total volatile basic nitrogen (TVB-N) and thiobarbituric acid reactive substances and decreases in the red indices of pork chunks compared with the control during refrigeration. Based on the national standards of total bacterial number and TVB-N of pork, treatment-3 extended the shelf-life of pork chunks by six days compared with the control. The results verified that chitosan-based coatings may be a practical method for the preservation of pork chunks during refrigeration.