The effect of chitosan edible coating containing garlic extract and coriander essential oil on microbial and sensory properties of rainbow trout fillet in refrigerated storage

Fish is a highly perishable food and it seems necessary to use natural preservative with antimicrobial properties. This study aimed to evaluate the effect of chitosan coating with garlic extract and coriander essential on microbial and sensory quality of rainbow trout fillet during 12 days at refrigerator storage condition. For this purpose, 8 treatments were prepared with chitosan coating containing garlic extract and coriander essential oil both separately and in combination forms (in amounts of 0.1 and 0.5%) and 2 control samples including control 1 (without coating) and control 2 (chitosan coating without extract and essential oil). Then all samples were evaluated by microbiological tests including total microbial counts, total psychotropic counts, and coliforms, and sensory properties including texture, color, odor, and overall acceptance at days of 0, 3, 6, 9, and 12 during storage. The results showed that the treatment coated with chitosan containing 0.5% garlic extract and 0.5% coriander essential oil had the lowest total microbial counts, total psychotropic counts and coliforms during 12 days of storage, and the highest amounts of microbial counts were observed in control 1 and then control 2 samples (P<0.05). Also the treatment with the highest amounts of garlic extract and coriander essential oil had better sensory scores by the end of storage period compared to control samples. So, it is suggested that chitosan coating with garlic extract and coriander essential oil as an antimicrobial agent, can be used for extending shelf-life of fish fillet.