Olive Oil Dregs as a Novel Source of Natural Antioxidants: Extraction Optimization towards a Sustainable Process
Open Access
- 18 June 2021
- Vol. 9 (6), 1064
- https://doi.org/10.3390/pr9061064
Abstract
Olive oil dregs (OOD), which are an underutilized by-product from oil mills, were used for the extraction of antioxidant compounds. The residues from three oil mills located in Campania (Southern Italy) were extracted with acidified methanol, and hydroxytyrosol (HT) was the main phenolic compound detected. Total phenolic content (TPC) and HT amount were measured. EVO Campania oil mill provided the residue with the highest TPC and HT quantities: 6.801 ± 0.159 mg Gallic Acid Equivalents (GAE)/g OOD and 519.865 ± 9.082 μg/g OOD, respectively. Eco-friendly extractions at different temperatures and times were performed on EVO Campania OOD, obtaining 9.122 ± 0.104 mg GAE/g OOD and 541.330 ± 64.087 μg/g OOD for TPC and HT, respectively, at 121 °C for 60 min. Radical Scavenging Activity (RSA), Superoxide Scavenging Activity (SSA), and Ferric Reducing Antioxidant Power (FRAP) were measured in OOD aqueous extracts. Extract prepared at 37 °C for 60 min showed the greatest RSA and SSA values (44.12 ± 1.82 and 75.72 ± 1.78, respectively), whereas extract prepared at 121 °C for 60 min exhibited the highest FRAP value (129.10 ± 10.49 μg Ascorbic Acid Equivalents (AAE)/mg). OOD extracts were able to protect sunflower oil from oxidation for 4 weeks at 65 °C. The overall results suggest that this novel residue can be usefully valorized by providing HT-rich extracts to use as antioxidant agents.Funding Information
- Fondazione Cariplo (2018-1001)
This publication has 41 references indexed in Scilit:
- Polyphenols: Multipotent Therapeutic Agents in Neurodegenerative DiseasesOxidative Medicine and Cellular Longevity, 2013
- Antioxidants, their properties, uses in food products and their legal implicationsInternational Journal of Food Studies, 2013
- Effects of Temperature and Time on Polyphenolic Content and Antioxidant Activity in the Pressurized Hot Water Extraction of Deodorized Thyme (Thymus vulgaris)Journal of Agricultural and Food Chemistry, 2012
- Determination of antioxidant properties of lyophilized olive leaf water extracts obtained from 21 different cultivarsFood Science and Biotechnology, 2012
- Improved Pyrogallol Autoxidation Method: A Reliable and Cheap Superoxide-Scavenging Assay Suitable for All AntioxidantsJournal of Agricultural and Food Chemistry, 2012
- Wastes Generated during the Storage of Extra Virgin Olive Oil as a Natural Source of Phenolic CompoundsJournal of Agricultural and Food Chemistry, 2011
- Phenolic and antioxidant potential of olive oil mill wastesFood Chemistry, 2011
- Dietary flavonoids: effects on endothelial function and blood pressureJournal of the Science of Food and Agriculture, 2006
- A Critical Evaluation of the Factors Determining the Effect of Intramolecular Hydrogen Bonding on the O-H Bond Dissociation Enthalpy of Catechol and of Flavonoid AntioxidantsChemistry – A European Journal, 2004
- Free Radical-Scavenging Properties of Olive Oil PolyphenolsBiochemical and Biophysical Research Communications, 1998