Abstract

Using natural preservatives has a probability to improve the quality and integrity of fish products. Such research investigated the antimicrobial and antioxidant effects of chitosan and chitosan nanoparticles casing on the quality of tilapia (Oreochromis niloticus) fish fillets through refrigerated storage. In the present investigation solutions of chitosan (1 and 2%) and nanochitosan (1 and 2%) were applied for the casing of tilapia fish slices thereafter stored at 4°C for 15 days. Uncoated (control) and coated fish fillets pieces were examined intermittently for bacteriological parameters (Total bacterial count, Proteolytic bacterial count, Lipolytic bacterial count, and Staphylococcus aureus count), quality parameters (pH, total volatile basic nitrogen (TVB-N), and thiobarbituric acid reactive substances, TBARS) and sensory features. Results showed that 2% chitosan and 2% chitosan nanoparticle solutions were the optimal concentrations for improving the quality of tilapia fish fillets until 10 days of refrigerated storage period compared to the control group. However, using 2% chitosan nanoparticles showed higher antimicrobial activity, strong ability in preventing protein degradation, retarding lipid oxidation, accepted pH values and delay in declining of sensory score more than 2% chitosan solution during the storage period. Therefore, 2% chitosan nanoparticles as a natural preservative can be utilized for the conservation of quality properties and expanding the shelf life of tilapia fish slices through chilled storage.