Antibacterial and Cytotoxicity Functions of Pomegranate Peel Extracts in Fish Processing

Pomegranate peel extracts, both ethanolic (PPE) and aqueous (PPA), demonstrated a broad spectrum of antibacterial action against Gr+ve and Gr-ve bacteria, with bacterial isolate B2 (G+ve cocci) having the maximum inhibition zone (IZ) 10.5–26.5 mm at concentrations 4.2 mg mL-1 to 267 mg mL-1. PPE's minimum inhibitory concentration (MIC) varies among bacterial strains, with the lowest being 8.3 mg mL-1. Ball-milled nano-scale pomegranate peel (NSPP) with 89.09 nm particle increased IZ 3-fold and decreased MIC significantly. MTT was used to assess the NSPPE's cytotoxicity against the Vero normal kidney and caco cell lines. At lower doses, NSPPE was safe, but increasing concentrations gradually lethal against Vero normal kidney cell line. NSPPE was highly toxic to caco cells, with an IC50 339.76 ± 13.9 µg mL-1. Fish kofta samples treated with NSPPE were completely free of Escherichia coli and Staphylococcus aureus after 8 weeks of storage. This study demonstrates that NSPPE may improve fish food safety and shelf life as a natural preservative.