Phytochemical Screening and Assessment of The Antioxidant Activity of Bio-phenols of Olive Oil Mill Wastewater From The Cold Extraction of Olive Oil in Khenchela Region Eastern of Algeria

The objective of this study was to evaluate in vitro the antioxidant activity of polyphenols from olive oil mill wastewater in Khenchela region eastern of Algeria after conducting a phytochemical screening. The extraction of polyphenols was done by the maceration method. The quantitative estimate of the total polyphenols and flavonoids was evaluated by the colorimetric method. Antioxidant activity was evaluated in vitro using three tests DPPH, ABTS and FRAP and ascorbic acid as a reference antioxidant. The results obtained showed that the phytochemical screening carried out allowed us to highlight the presence of polyphenols, flavonoids, tannins and reducing sugars with large quantities, sterols and terpenoids in lesser amounts. The values of total polyphenols and flavonoids were sequential: (925.8 ± 8.1 µg GAE/mL) and (45.97 ± 9.5 µg QE /mL). The values of the antioxidant activity obtained from the three tests DPPH, ABTS, and FRAP were successively the followings: (IC 50: 144.52 ± 1 µg/mL), (IC 50 : 169.6 ± 35.3 µg/mL) and (IC 50 : 248.13 ± 10.1 µg/mL). At the end of this study, it appears that OMW polyphenolic extract has an important antioxidant power.