Antibacterial Effects of Pomegranate Peel Extract on Staphylococcus, Bacillus, and Salmonella spp.

This study examined the physicochemical properties and antibacterial activity of fresh fruit peels of the local Zivzik pomegranate (Punica granatum L.) grown in the Şirvan district of Siirt. Total phenolic content, antioxidant capacity (CUPRAC and DPPH), pH, oxidation-reduction (O/R) potential, water activity (aw), and soluble dry matter content were analyzed in extracts prepared from the fresh peels. Antibacterial activity was evaluated against Staphylococcus aureus, Bacillus subtilis, and Salmonella Typhimurium and compared with reference antibiotics. The total phenolic content of the peel extract was 6.827±0.495 mg GAE/mL, while antioxidant capacity measured 17.872±0.541 mg TE/mL (CUPRAC), and DPPH radical scavenging activity reached 1.332±0.003 mg AAE/mL. The extracts exhibited a pH of 3.657±0.031, an O/R potential of 201.200±0.721 mV, and an aw of 0.952±0.001. Soluble dry matter contents were 17.833±0.208 °Brix for the ethanol extract and 11.400±0.541 °Brix for the methanol extract. Microbiological assessments showed that the ethanol extract produced the strongest inhibition against Bacillus subtilis (14.33 mm; ++), while Salmonella Typhimurium exhibited the lowest sensitivity (10.33 mm; +). A statistically significant interaction between solvent type and extract concentration was observed only for B. subtilis (P