Natural Biopreservation of Sea Bream Fillets Using Bioactive Fractions Extracted from Echinoderms

In the last decade, researchers’ attention has focused on the study of antimicrobial peptides (AMPs), small protein molecules that constitute the first line of defence of organisms against a great variety of external agents, and they have been isolated from several prokaryotic and eukaryotic organisms, such as echinoderms. In this study, the extracts of Arbacia lixula (sea urchin) and Holothuria tubulosa (sea cucumber) coelomocytes were tested to evaluate their antimicrobial activity. The results highlighted the greater antibacterial efficacy of sea cucumber compared to sea urchin. For this reason, to evaluate the efficacy as natural preservatives, sea cucumber extract was dispensed on pieces of sea bream fillets (Sparus aurata). The results obtained showed that the H. tubulosa extract exerted a selective inhibitory effect on specific bacterial groups (staphylococci and presumptive E. coli) and contributed to better-preserved freshness of the product, as indicated by the assessment performed with the modified Quality Index Method (QIM).