Effects of bacteriocine Z on the shelf-life of silver carp fillets during refrigerated storage

Because of the high perishability of fish, keeping the quality of fresh fish is one of the most important problems in the fish-processing industry and for the consumers. The aim of this study was to determine the antibacterial and antioxidant effects of bacteriocine Z on silver carp fillets during refrigerated storage. After being weighed, fish fillets were sprayed with nisin Z (0.2 g/kg) packaged in vacuum and refrigerated (4°C). Microbial (TVC, PTC, LAB) and chemical (PV, TBA, TVB-N) parameters were measured at days 0, 3, 6 and 9. As compared with the nisin Z-treated fish samples, the psycrotrophic, lactic-acid, and aerobic-mesophilic bacterial counts were higher in the control samples. The microbial parameters decreased significantly in the nisin Z-treated samples at the beginning of the period, followed by a slower rate of increase than the control; the chemical parameters showed a slower rate of decrease. Using metabolites as natural preservatives in fish fillets may increase shelf-life of silver carp fillets during refrigerated storage. Bacteriocine Z may extend their shelf-life at 4˚C by 3 days.