Enhancing microbial management and shelf life of shrimp Penaeus vannamei by using nanoparticles of metallic oxides as an alternate active packaging tool to synthetic chemicals

Abstract

Abstract Extensive use of chemicals in food processing and packaging attracted the public attention because of serious health problems. Hence, the application of inorganic antimicrobial compounds can be a safe and potential approach in this regard. In this study nanocomposite films containing NPs of three metallic oxides alone i.e. SiO, ZnO and CuO or in combinations i.e. SiO-ZnO, SiO-CuO, ZnO-CuO supported by 4A zeolite (4A z) were evaluated for their antibacterial potential to manage the microbial load in both raw and inoculated refrigerated shrimp. The antibacterial potential of NPs doped on 4A z determined through well diffusion method, MIC, MBC, FIC and %live/dead proportion, indicated strong activity of NPs against a range of food born and pathogenic bacteria i.e. Staphylococcus aureus, Listeria monocytogenes, Escherichia coli, Pseudomonas fluorescens, Vibrio parahaemolyticus and Aeromonas caviae. Nanocomposite films containing NPs were also found active against the in vitro growth of these bacteria. It was shown that nanocomposite film having NPs significantly reduced the total viable, Shewanella putrefaciens, Enterobacteriaceae and Pseudomonas spp. count in raw shrimp and L. monocytogenes, S. aureus and E. coli count in inoculated shrimp as well as exhibited higher scores for sensory evaluation as compared to control. Generally, the treatment SiO-ZnO NPs was more effective than other treatments while the CuO NPs was least effective. From these results it is concluded that nanocomposite films, by limiting chemical use, could act as novel, low cost, safe and effective packaging approach for microbial management as well as enhancing the shelf life of refrigerated shrimp.