Effect of a chitosan-based nanocomposite containing ZnO and Zataria multiflora essential oil on quality properties of Asian sea bass ( Lates calcarifer ) fillet.

This research aimed to estimate the effects of chitosan (CH) coating in combination with zinc oxide nanoparticles (ZnONPS) and  Zataria multiflora  essential oil (ZEO) on the bacterial and biochemical properties of the Asian sea bass ( Lates calcarifer ) fillets during refrigeration storage (4 ± 1 °C). The fillets were randomly divided into five treatments (CH, CH-ZnONPS, CH-ZEO, CH-ZnONPs-ZEO, and control). Then, the treated fillets were kept at 4 °C and quality analysis was performed on days 0, 4, 8, 12, and 16. The results revealed that the combination of ZnONPs and ZEO with CH coating is an active coating with antimicrobial effects. Also, the coated fillets improved the biochemical properties (such as FFA, TBA, TVBN, pH) as well as color properties during refrigeration storage. The highest rate of FFA (3.59 ± 0.08%oleic acid), TBA (1.43 ± 0.00 mg MDA/kg), TVBN (30.82 ± 0.30 mg/N100g), and pH (7.38 ± 0.03) was recorded in control fillets while the lowest rate of FFA (2.19 ± 0.00%oleic acid), TBA (0.61 ± 0.00 mg MDA/kg), TVBN (19.60 ± 0.20 mg/N100g), and pH (6.99 ± 0.04) was recorded in CH-ZnONPs-ZEO coated fillets ( p  < 0.05) on day 16. The sensory acceptance score was better than that of the control treatment on days 8 and 12 in Sea bass fillet coated with CH-ZnONPs, and CH-ZnONPS/CH-ZEO, respectively, and it was lower the critical score for fishery products. The combination of nanoparticles or essential oils (individually or in combination together) with edible coatings (chitosan) could increase and optimize the storage time of refrigerated seafood.