Antioxidant and Antibacterial Activities of Juniperus phoenicea Leaf and Berry Extracts

AbstractThe leaves and berries of Juniperus phoenicea L., collected from eastern Algeria, wereanalyzed for their phenolic composition, antioxidant activity, and antibacterial effects againstselected foodborne pathogens. The dried plant material was extracted with a methanol/water(80:20, v/v) solution and subsequently fractionated into chloroform, ethyl acetate, and n-butanol. The extracts and fractions were assessed for total phenolic content (TPC), totalflavonoid content (TFC), antioxidant activity using DPPH, ABTS, CUPRAC, and galvinoxylassays, and antibacterial activity through disk diffusion and minimum inhibitoryconcentration (MIC) determination. The leaves exhibited a higher phenolic content comparedto the berries, with the ethyl acetate fraction of the leaves demonstrating the highest TPC(459.78 ± 9.60 μg GAE/mg extract) and TFC (47.34 ± 2.45 μg QE/mg extract). This fractionalso exhibited the most potent activity in the ABTS (IC50 = 4.39 ± 0.12 μg/mL), CUPRAC(A0.5 = 8.17 ± 0.62 μg/mL), and galvinoxyl (IC50 = 9.19 ± 0.29 μg/mL) assays.Antibacterial activity was predominantly associated with the methanolic fractions,particularly the berry methanolic extract against Salmonella enteritidis (13.5 ± 0.71 mm; MIC= 0.15625 mg/mL). Overall, J. phoenicea exhibited distinct organ- and solvent-dependentprofiles: the leaf ethyl acetate fraction was the most potent antioxidant, whereas themethanolic fractions were more significant for antibacterial screening. These findings warrantfurther investigation of J. phoenicea extracts as natural, multifunctional ingredients for foodpreservation.