Chitosan Extends the Shelf-life of Filleted Tilapia (Oreochromis niloticus) During Refrigerated Storage

摘要

Shelf-life extension of aquatic products is of significant economical importance.To determine the potential effect of chitosan on the shelf-life of filleted tilapia,this study analyzed the bacterial community diversity in fresh and spoiled tilapia fillets stored at(4±1)℃ and examined the antimicrobial activity of chitosan against relevant bacteria isolates.Results showed that Pseudomonas(20％)and Aeromonas(16％)were abundant in fresh tilapia fillets,whereas Pseudomonas(52％),Aeromonas(32％)and Staphylococcus(12％)were dominant in the spoiled samples.Chitosan showed wide-spectrum antibacterial activity against bacteria isolated from tilapia and 5.0 g L-1 chitosan was selected for application in preservation.We further determined the shelf-life of chitosan-treated,filleted tilapia stored at(4±1)℃ based on microbiological,biochemical and sensory analyses.Results showed that the shelf-life of chitosan-treated,filleted tilapia was extended to 12 d,whereas that of untreated,control samples was 6 d.These indicate that chitosan,as a natural preservative,has great application potential in the shelf-life extension oftilapia fillets.