Preservative effects of cumin (<i>Cuminum cyminum</i>) and black zira (<i>Bunium persicum</i>) essential oil emulsion-based gelatin coating on rainbow trout (<i>Oncorhynchus mykiss</i>)

Abstract In this study, gelatin-based edible coatings loaded with Cuminum cyminum essential oil (CEO) and/or Bunisum persicum essential oil (BEO) emulsions were fabricated and their effect on extending the shelf life of whole ungutted rainbow trout fish was investigated. The physicochemical, microbial, and sensory properties of the fish during 20 days of storage were examined. The gas chromatography (GC) analysis of EO components revealed that cuminaldehyde (31.36%) and gamma-terpinene (36.12%) were the major components of CEO and BEO, respectively. The total viable, psychrophilic, and lactic acid bacteria count of samples treated with active edible coatings were significantly lower than those coated with gelatin and control samples. The highest and lowest pH values were obtained for the control sample (6.87) and the samples containing CEO (6.40), respectively. The lowest thiobarbituricacid reactive substances and total volatile basic nitrogen values were obtained in fish coated with gelatin containing 1.5% CEO and BEO. The best sensory score was achieved for the sample treated with both EOs. Therefore, using gelatin coating loaded with CEO and BEO can improve the shelf life of fish.