olive leaves

The aim of this study was to evaluate the In vitro antioxidant activity of the phenolic extracts of olive leaves and olive mill wastewater and their protective effect against lipid peroxidation. The antioxidant activity of two varieties (Chemlal and Sigoise) of the tested olive leaves and olive mill wastewater was evaluated using three different antioxidant assays (DPPH radical scavenging test, ferric reducing antioxidant power (FRAP) assay, and hydrogen peroxide scavenging assay). The protective effect of the tested extracts against lipid peroxidation in an in vitro model of rat liver homogenate was evaluated through the production of thiobarbituric acid reactive substances (TBARS). The obtained results showed that the phenolic extracts of olive leaves and olive mill wastewater are rich in phenolic compounds mainly flavonoids, with the highest content found in the extract of Chemlal olive leaves (88.35±0.73 mg GAE/g of extract for polyphenols and 45.98±0.36 mg QE/g of extract for flavonoids). Furthermore, significant anti-free radical activity and reducing power have been shown by the tested extracts. In fact, hydrogen peroxide (H2O2) can be neutralized by the studied extracts. The extract of Chemlal olive leaves exhibited the most important antioxidant activity. The tested extracts showed a significant decrease in malonic dialdehyde (MDA) levels and a protective effect against lipid peroxidation. The high protective effect was exhibited by the phenolic extract of Chemlal olive leaves. According to the obtained results, it appears that the phenolic extracts of olive leaves and olive mill wastewater have an important antioxidant potential and protective effect against lipid peroxidation and they can be used as natural antioxidant agents in food and pharmaceutical industries.

Author(s) Details:

Fatiha Abdellah
Laboratory of Research on Local Animal Products at Ibn Khaldoun University, Tiaret, Algeria.


Also See : The Western Blot Assay Showed the Presence of 55kDa and 35kDa Bands : A Part from the Book Chapter : Midgut Binding Activity of Mosquitocidal Extracellular Protein of Pseudomonas fluorescens Strain


Recent Global Research Developments in  Antioxidant Properties of Olive Mill Wastewater

Olive Mill Wastewater (OMW) Extracts: [1]

  • Extracting polyphenols from olive mill wastewater using water (instead of methanol–water) yielded a similar content of phenolic compounds.
  • The main polyphenols in the water-extracted OMW were hydrotyrosol and tyrosol.
  • The antioxidant capacity of the water-based OMW extract was comparable to that of the methanol-based extract at very diluted concentrations.

Olive Leaf Extracts:

  • The methanol-free extract (recovered in water after initial extraction with methanol–water) had a lower total phenol content compared to the methanolic extract.
  • The primary polyphenol in the water-based leaf extract was oleuropein.
  • Both water-based extracts exhibited similar antioxidant capacity at very low concentrations.

New innovation in order to recover the polyphenols of olive mill wastewater extracts for use as a biopesticide against the Euphyllura olivina and Aphis citricola

  • Results from physicochemical analysis of olive mill wastewater (OMW) have shown that total suspended solids (5.170 to 0.658 g/L), chemical oxygen demand (124.400 ± 25.442 g/L), biochemical oxygen demand (60.593 ± 6.276), total organic carbon (3.317 ± 0.350 g/L), and Kjeldahl nitrogen (0.126 ± 0.044 g/L) far exceed discharge standards. The concentrations of the major constituents of phenolic extracts of OMW can cause mortality of the pests Euphyllura olivina and Aphis citricola. [2]

References

  1. Hernández-Fernández A, Garrido Y, Iniesta-López E, Pérez de los Ríos A, Quesada-Medina J, Hernández-Fernández FJ. Recovering Polyphenols in Aqueous Solutions from Olive Mill Wastewater and Olive Leaf for Biological Applications. Processes. 2023; 11(9):2668. https://doi.org/10.3390/pr11092668
  2. Larif, M., Zarrouk, A., Soulaymani, A. et al. New innovation in order to recover the polyphenols of olive mill wastewater extracts for use as a biopesticide against the Euphyllura olivina and Aphis citricola . Res Chem Intermed 39, 4303–4313 (2013). https://doi.org/10.1007/s11164-012-0947-5

To Read the Complete Chapter See Here

By Editor

Leave a Reply