Antibacterial activity of pomegranate fruit peels and arils

The in vitro antibacterial activities of different extracts of pomegranate fruit peels and arils (with seeds) were investigated by agar-well diffusion and broth dilution methods against four food-related bacteria (Bacillus subtilis, Staphylococcus aureus, Escherichia coli, and Salmonella typhimurium). The solvents used as extractants in this study were hot water, 95% ethanol, and acetone. Their total phenolic contents were also evaluated. All pomegranate extracts contained high levels of phenolics and exhibited antibacterial activity against all bacteria tested. The hot-water extract of the peels was the most potent with the minimal inhibitory concentration of 207 mg/ml against E. coli and less than 103.6 mg/ml against the other bacteria. Gram-positive bacteria were generally more sensitive to the extracts than Gram-negative ones.