A new method to bio-preserve sea bass fillets

In this work a bio-preservation technique was applied to sea bass fillets in order to preserve their quality. The preservation consisted in the application of two kinds of active coatings on the product surface differing in the fermentation time of alginate solution by L. reuteri plus glycerol (24 and 48 h). This technological strategy was chosen because it has been demonstrated that L. reuteri produces the reuterin as an intermediate metabolite during the anaerobic fermentation of glycerol. To assess the antimicrobial effects of sodium alginate with L. reuteri and glycerol, both in vitro and in vivo tests were carried out. The active films, in particular at 48 h fermentation, showed a good antibacterial activity, confirmed also by the major reuterin concentration. To prove the effectiveness of the treatments, microbial and sensory attributes were monitored by in vivo test on fish fillets. Results highlighted that the two active sodium alginate coatings showed a good antibacterial activity. In sea bass fillets stored at 4 °C, proliferation of main spoilage microorganisms was delayed with a consequent preservation of sensory attributes. In particular, it was found that improving the fermentation time (48 h) a better microbiological and sensory quality was achieved.