Study the effect of nanochitosan with sodium acetate coating on shelf life of Rainbow trout filet (Onchorynchus mykiss) in refrigerator temperature

Rainbow trout filet is a high nutritive value product that can be introduced to consumers successfully which have short shelf life. In this study, the effects of Nano-capsulated chitosan analyzed with and without sodium acetate coatings on increasing the shelf life of refrigerated Rainbow trout filets (Onchorynchus mykiss) during refrigerator storage (4±1°C) and in polyethylene with zipper bag during 16 days. For this purpose, the Rainbow trout filets were immersed in five treatments that included: solutions of NCH1%, NCH2%, NCH1%+NaOAC1.5%, NCH2%+ NaOAC1.5% and distilled water solution as a control sample. The antimicrobial effect of Nano-capsulated chitosan coating with and without sodium acetate was evaluated by counting of aerobic mesophilic bacteria, lactic, psychrophilic bacteria and chemical properties including pH, TBA, PV and TVB-N. Sensory evaluation determined by 5 evaluator persons who were asked to evaluate the flavor, odor, color, texture and overall acceptability of samples in days 0, 3, 6, 10, 12. Sensorial, chemical and microbial results evaluated by ANOVA and Duncan tests. Sensorial, chemical and microbial results showed that in end of storage Nano-capsulated chitosan with and without sodium acetate 1.5% were better significantly compared to control group (p<0.05). In this study, the sample contained NCH2%+ NaOAC1.5% coating treatment showed the best results of storage. The results of Sensorial, chemical and microbial tests of Nano-capsulated chitosan and Nano-capsulated chitosan with sodium acetate indicted that shelf life storage were increased from 6 days in control treatment to 12 and 16 days, respectively.