Antioxidant Potential of Olive Pulp Phenolic Extracts and Their Protective Effect against Lipid Peroxidation

AbstractOlive (Oleaeuropaea L.) is one of the most widelyused medicinal plants in traditional medicine. It is rich in bioactivecompounds with beneficial properties. Extracts from its fruits contain various constituents, including polyphenols andflavonoids, which are known for their strong antioxidant activity.This study was conducted to evaluate the antioxidantactivity of phenolic extracts from olive pulp (Oleaeuropaea L.) of the Chemlal and Sigoise varieties using three standardassays: reducing power, DPPH radical scavenging, and hydrogen peroxide neutralization. Lipid peroxidation was assessed bymeasuring thiobarbituric acid reactive substances (TBARS). Quantitative analysis revealed that olive pulp is rich inpolyphenols and flavonoids, although flavonoid content was lower compared to polyphenols. The results showed that thephenolic extracts of olive pulp exhibited strong DPPH• scavenging activity, with IC50 values of 158.1 ± 2.57 μg/mL for olivepulp extract from Chemlalvariety and 174.11 ± 2.20 μg/mL for Sigoiseolive pulp extract. This antioxidant potential wasfurther supported by the reducing power assay, which showed EC50values of1301 ± 57.79 μg/mL and 1468.99 ± 0.94 μg/mLfor the Chemlal and Sigoise varieties, respectively. In addition, the extracts efficiently neutralized hydrogen peroxide (H2O2),with IC50 values of 117.32 ± 2.36 μg/mLforChemlal varietyand 493.29 ± 1.3 μg/mL for Sigoise variety. Moreover, bothextracts demonstrated a significant protective effect against lipid peroxidation. Overall, the findings highlight the richness ofolive pulp phenolic extracts in bioactive compounds with strong antioxidant activity, suggesting their potential application asnatural antioxidants in the food and pharmaceutical industries.