Spatial Variation of Phytochemical and Antioxidant Activities of Olive Mill Wastewater: A Chemometric Approach

Abstract

Olive mill wastewater (OMW) was obtained during the extraction of olive oil. It is typified by an elevated concentration of sugars, acids, proteins, polyphenols, and organic matter. This makes the removal of OMW problematic for all olive oil-producing countries. Due to their high concentration in polyphenols, these wastewaters are a source of danger to the environment. This research aimed to study the spatial distribution effect in terms of geographical origin production of olive oil on the phenolic content and the antioxidant activity of the OMWs. A chemometric approach using principal component analysis (PCA) and hierarchical cluster analysis (HCA) was utilized. Physico-chemical characterization of OMWs was performed to evaluate their pollutant load by setting the following parameters: pH, dry matter, conductivity, and chemical oxygen demand. Quantitative analysis of the phenolic compounds shows that the extract of all samples had a high content of phenolics varying from 238.26 ± 5.67 to 534.16 ± 3.83 mg GAE/g of extract, flavonoids varying from 179.89 ± 1.64 to 421.47 ± 3.42 mg QE/g of extract, and tannins varying from 101.66 ± 0.65 to 216.28 ± 3.41 mg CE/g of extract. Antioxidant activity was determined by two testing systems: DPPH and ABTS assay. The IC50 DPPH varied from 0.30 ± 0.08 to 1.93 ± 0.34 µg/mL, while it varied between 2.04 ± 0.16 and 6.11 ± 0.25 µg/mL for the IC50 ABTS method. The principal component analysis indicated that the two methods DPPH and ABTS are strongly correlated. Furthermore, important correlations were shown by the principal component analysis (PCA) on the one hand between the phenolic compounds and on other hand between their antioxidant activities (DPPH, ABTS).

Fungal Strain as Biological Tool to Remove Genotoxicity Effect of Phenolic Compounds from Olive Mill Wastewater

“…In Morocco, a discharge of about 250,000 tons of olive mill wastewater containing high contents of toxic organic chemical substances material, mainly the phenolic compounds, are produced by olive oil production units [2]. The olive mill wastewaters are discharged into the sewerage network and/or stored in evaporation ponds to reduce their volume and/or are spread directly on the soil and result in adverse environmental impacts [3][4][5]. Their high pollution load is due to their high organic matter content such as sugars, tannins, phenolic compounds, polyalcohols, pectins and lipids compounds [3].…”