Effect of Chitosan Extracted from Shrimp (Metopenaus affinis) on the Shelf life of Grass Carp (Ctenopharyngodon idella) Fillet in Vacuum Packaging

In this study, the effect of chitosan extracted from Metopenaus affinis was investigated in five treatments of 0, 0.5, 1, 1.5 and 2% on the shelf life of grass carp (Ctenopharyngodon idella) fillets in vacuum packaging for 15 days at refrigerator temperature. Chemical parameters of sp (pH, TVB-N, TBA, PV, FFA) and microbial count (TVC) as well as tissue properties, including hardness, cohesion, elastic, gum and chewing factors were measured. The results showed that there was a significant increase in pH during the storage, and in all treatments, changes were significant on day 15 compared to the zero day. By the 12th day, the amount of peroxide increased. The amount of TBA was exceeded at the 9th, 12th and 15th days except in the 2% chitosan treatment (on day 9). The amount of volatile nitrogen basic in the 15 days increased and from day 9 all treatments (except 2% chitosan) were desirable. The amount of microbial count of control treatment was eliminated on days 12 and 15. In addition, the results showed that chitosan had no significant changes in tissue properties (P>0.05). The results showed that the grass carp fillet with 2% chitosan coating until 15 days had a good quality.