Antioxidant Properties and Protective Effect of Olive Mill Wastewater Against Lipid Peroxidantion

Abstract

Olive mill wastewater generated from olive oil industry can indeed be a significant environmental concern due to its pollution potential. It contains various pollutants, including organic matter, phenolic compounds, which can be harmful to the environment if not properly managed. Despite its pollution olive mill wastewater is a rich source of natural antioxidant (polyphenols). The objective of this study is to evaluate the antioxidant activity and the protective   effect of the phenolic extracts of olive mill wastewater against lipid peroxidation. The antioxidant activity of the phenolic extracts of olive mill wastewater (OMWW) was evaluated using three tests, DPPH radical scavenging test, ferric reducing antioxidant power (FRAP) assay and the neutralization of hydrogen peroxide. The protective effect of the tested extracts against lipid peroxidation was evaluated in an in vitro model of rat liver homogenates through the production of thiobarbituric acid reactive substances (TBARS). The results showed that the phenolic extracts of olive mill wastewater are rich in phenolic compounds mainly flavonoids, with the highest content found in Chamlal OMWW (43.53±0.56 mg GAE/g of dried extract for polyphenols and 14.12± 0.014 mg QE/g of dried extract for flavonoids). Moreover, the studied extracts have demonstrated an important anti-free radical activity and reducing power. Indeed, these extracts are also capable to neutralize hydrogen peroxide (H₂O₂). Chamlal OMWW showed the highest antioxidant activity.  The studied extracts exhibited a protective effect against lipid peroxidation and decrease malonic dialdehyde (MDA) level. Chamlal OMWW showing the highest protective effect. In the light of the obtained results, olive mill wastewater has an important antioxidant potential   and it can be used as natural agents in food and pharmaceutical industries further its negative environmental impact can be reduced.