The effect of chitosan-based edible coating containing Dunaliella algae extract on the qualitative and microbial characteristics of Beluga Sturegeon (Huso huso) fillet during the storage period

The rate of spoilage and oxidation in fish and the change in color of fish tissue, its shelf life is limited; therefore, it is necessary to use natural antioxidants to delay, control or inhibit these adverse reactions and prevent the reduction of food quality. The current study was conducted to determine the effect of chitosan-based edible coating containing Dunaliella alga extract on preservation the quality of fresh Huso huso fillet during storage in refrigerator. Microbial and chemical tests including total bacterial load and saline bacteria, pH, TBA as well as sensory evaluation were performed periodically for all samples and for algae extract, antioxidant activity was measured by DPPH method. The total bacterial count on the 10th day of storage for samples coated with algae extract was 6.17±0.22 log CFU/g, which was in the acceptable range for human consumption, but in control samples was 9.41±0.20 log CFU/g on the 10th day, which is beyond the permissible limit. The amount of psychotropic bacteria for the control treatment significantly (p<0.05) increased compared to the chitosan-coated treatment containing the extract. The values of pH and TBA in the control sample were significantly higher compared to the treated sample on the 5th and 10th days of storage (p<0.05). This study showed that the growth of bacteria in fresh fish fillets can be prevented by using chitosan coating containing algae extract, and its sensory characteristics, including texture, smell, color, and general acceptability, have been preserved to a great extent and increased the period of keeping fish in the refrigerator.