New technique for improving fish packaging hygiene and prolonged shelf life

Abstract

Zinc oxide nanoparticles (ZnO NPs) have received great attention due to their optical, physical, and antimicrobial properties. They have toxic effect against microbes without any effect on mammalians cells. They are used in several applications including extending the shelf life of food. The study aims to determine the minimum inhibitory concentrations of ZnO NPs against different aquaculture fish fungus species and their storage period. A total of 160 samples were collected from different types of aquaculture fish samples as follows: rabbitfish, bream, red mullet, saddle grouper, spangled emperor, gilthead seabream, mackerel fish, and Asian seabass. ZnO NPs activity against the isolated fungus species was evaluated by estimating minimum fungicidal inhibitory concentration and inhibition of fungal enzymes (amylase, protease, and lipase). The storage period of the fish in a package containing ZnO NPs was determined by estimating the sensory characteristics of the treated fish. The results obtained recorded the following fungus species from aquaculture fish samples: Aspergillus niger (gi: JX112703), Aspergillus oryzae, Aspergillus awamori, Penicillium species, Aspergillus tubingensis, Trichosporon montevideense, A. niger (gi: MG889596), and Byssochlamys spectabilis, respectively. This study is the first to apply ZnO NPs for fish preservation which have a powerful antifungal effect against all the isolated fungi. The study recommends using 3% ZnO NPs in fish packaging film; it inhibited most of the fungus species, extending the shelf life of most of the fish species to more than 15 days.