Antibacterial Effects of Pomegranate Peel Extract on Staphylococcus

Abstract: 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<0.05)

indicating species-specific variability in response to extract composition. The extracts also generated inhibition levels greater than several standard antibiotics evaluated under identical conditions. Overall

the findings indicate that Zivzik pomegranate peel constitutes an effective natural antimicrobial source with practical applicability in food processing systems seeking to enhance microbial safety through non-synthetic preservation strategies.