Postbiotics enhance the functionality of a probiotic edible coating for salmon fillets and the probiotic stability during simulated digestion

Abstract

This study developed a postbiotics fortified probiotic coating for salmon fillets. Postbiotics generated by a pre-fermentation of Lactiplantibacillus plantarum 299 V was added in the coating together with the probiotic bacteria cells. The microbiological analysis results revealed that the fortified coating significantly inhibited the proliferation of psychrophilic bacteria, Pseudomonas spp., Enterobacteriaceae, as well as the spiked Listeria monocytogenes on the salmon fillets during a refrigeration storage of 9 days (P < 0.05). Correspondingly, the generation of biogenic amines and total volatile basic nitrogen was also suppressed significantly by the postbiotics fortified coating (P < 0.05). L. plantarum 299 V on the coated fish fillets manifested excellent stability both during the refrigeration storage and the in vitro simulated digestion. Taken together, the postbiotic fortified probiotic coating reported in this study enhanced the microbial quality and safety of the salmon fillets, and was also recognized as a novel probiotic vector to promote human health.