Antioxidant Activity of Pomegranate Peel Extracts (lat. Punica granatum L.): Effects of Extraction Solvent and Technique on Antioxidant Activity

Abstract

This study focuses on evaluating the antioxidant activity of pomegranate (lat. Punica granatum L.) peel extracts obtained through various extraction methods, including ultrasound-assisted extraction (UAE), Soxhlet extraction, and maceration, using methanol and 96% ethanol as solvents. These techniques were chosen for their differing effects on the preservation of thermosensitive phytochemicals. Antioxidant potential was assessed using the DPPH radical scavenging assay, with absorbance measured at 517 nm using a UV-Vis spectrophotometer. The results demonstrated that the efficiency of antioxidant activity largely depended on the extraction method and solvent used. A lower IC50 value indicates higher antioxidant activity, as it reflects a greater efficiency in neutralizing free radicals at a lower concentration. Extracts obtained by ultrasound-assisted extraction exhibited the highest radical scavenging capacity with an IC50 value of 19.049 μg/mL, while those obtained by Soxhlet extraction with ethanol showed comparatively weaker activity with an IC50 value of 34.210 μg/mL, likely due to the thermal degradation of sensitive bioactive compounds. The maceration method, although mild and solvent-efficient, yielded moderate antioxidant activity, highlighting the balance between extraction intensity and preservation of functional constituents. The study emphasizes the importance of optimizing extraction conditions to maximize the recovery of bioactive compounds from plant materials. Given the phytochemical richness and biological potential of pomegranate peel, the findings support its application as a natural source of antioxidants in the development of dermocosmetic and pharmaceutical formulations aimed at combating oxidative stress and disorders related to hyperpigmentation and skin aging.