Effect of Edible Chitosan Coating Containing Froriepia subpinnata Extract on Shelf life of Nile tilapia (Oreochromis niloticus) Fillet at Refrigerated Temperature

Natural antimicrobial and antioxidant compounds in extracts and essential oils of plant can be used in the edible coatings for packaging of food product. The aim of this study was to investigate the effect of edible chitosan containing Froriepia subpinnata extract on storage time of Nile tilapia (Oreochromis niloticus) fille After preparation of fresh fish, except the control group (first treatment), fish fillets were coated with 2% chitosan solution (second treatment), 2% chitosan solution and 1% F. subpinnata extract (third treatment) and 2% chitosan solution and 2% F. subpinnata extract (fourth treatment) then kept at refrigerator temperature for 21 days. At the beginning of the experiment and at 7th, 14th and 21st days, chemical indexes (pH, total volatile nitrogen bases and thiobarbituric acid), microbial count (mesophilic bacteria, enterobacteriaceae, psychrophile bacteria and mold and yeast) and sensory evaluation of samples were analyzed. Generally, coated treatments showed better quality than the control group in terms of investigated microbial and chemical indexes. Also, the treatment coated with chitosan and 2% of F. subpinnata extract showed significant differences (P˂0.05) compared to the control group in terms of studied indexes until 21st day, and was known the best treatment beside the other treatments. Coating of tilapia fillets with chitosan containing 2% of F. subpinnata extract improves chemical and microbial indexes and increases their shelf life up to 14 days in comparison with control.