Optimizing Natural Methods to Extract Antioxidants from Olive Waste

Jenn Hoskins
22nd May, 2024

Optimizing Natural Methods to Extract Antioxidants from Olive Waste

Image Source: Natural Science News, 2024

Key Findings

  • Researchers at Universidad de la República studied extracting antioxidants from Uruguayan olive pomace using natural deep eutectic solvents (NADES)
  • They found lactic acid-glucose (La-Gc) to be the most effective NADES for extracting phenolic compounds
  • Optimal extraction conditions were 80°C, 68% water in NADES, and a solid-liquid ratio of 0.014 g/mL, yielding higher antioxidant activity than conventional solvents
The study conducted by researchers at Universidad de la República explored the use of natural deep eutectic solvents (NADES) for extracting phenolic compounds with antioxidant activity from Uruguayan olive pomace (OP), a by-product of olive oil mills[1]. This research aimed to find an efficient and environmentally friendly method to extract valuable phenolic compounds from OP, which is often considered waste. The researchers tested nine different NADES and found that lactic acid-glucose (La-Gc) was the most effective solvent for phenolic compound extraction. They then focused on optimizing the extraction process using La-Gc. To do this, they employed response surface methodology, a statistical technique that helps analyze the effects of multiple variables. In this case, they looked at the impact of extraction temperature, water content in NADES, and the solid-liquid ratio on total phenolic content (TPC) and antioxidant activity. The study found that temperature and the solid-liquid ratio greatly influenced both TPC and antioxidant activity, while the water content in NADES significantly affected only the antioxidant activity. The optimal extraction conditions were determined to be 80 °C, 68% (w/w) water in NADES, and a solid-liquid ratio of 0.014 g/mL. Under these conditions, the researchers achieved a TPC of 15.56 mg GAE/g db, a Ferric Reducing Antioxidant Power (FRAP) of 178.14 μmol FSE/g db, and a DPPH radical scavenging activity of 72.75 μmol TRE/g db. Additionally, the hydroxytyrosol content was found to be 1.24 mg/g db. These values were significantly higher than those obtained using conventional solvents under identical conditions. This study builds on prior research that has explored various methods for extracting phenolic compounds from olive oil by-products. For example, one study investigated the hydrothermal treatment of olive oil waste and found that it led to a high concentration of simple phenolic compounds with significant antioxidant activities[2]. Another study evaluated the use of steam explosion and phenol extraction from Olive Mill Solid Waste (OMSW), showing that steam explosion could double the total phenol content compared to raw OMSW[3]. Additionally, previous research has demonstrated the effectiveness of NADES in extracting phenolic compounds from virgin olive oil, highlighting their efficiency and environmental friendliness[4]. The current study expands on these earlier findings by demonstrating that NADES, specifically La-Gc, can be used to extract phenolic compounds from OP more effectively than conventional solvents. This is significant because it provides a more sustainable and efficient method for utilizing a by-product that is often discarded. Moreover, the use of NADES aligns with the growing interest in green chemistry, which seeks to reduce the environmental impact of chemical processes[5]. In summary, the research conducted by Universidad de la República highlights the potential of using La-Gc NADES for extracting phenolic compounds with high antioxidant activity from olive pomace. This method not only enhances the value of olive oil by-products but also offers a more sustainable and efficient alternative to conventional extraction methods. By optimizing the extraction conditions, the researchers have demonstrated that this approach can yield higher concentrations of valuable phenolic compounds, contributing to the broader field of sustainable and green chemistry.



Main Study

1) Extraction of phenolic compounds with antioxidant activity from olive pomace using natural deep eutectic solvents: modelling and optimization by response surface methodology

Published 21st May, 2024


Related Studies

2) New phenolic compounds hydrothermally extracted from the olive oil byproduct alperujo and their antioxidative activities.


3) Phenols recovery after steam explosion of Olive Mill Solid Waste and its influence on a subsequent biomethanization process.


4) Phenolic compounds from virgin olive oil obtained by natural deep eutectic solvent (NADES): effect of the extraction and recovery conditions.


5) Tailoring properties of natural deep eutectic solvents with water to facilitate their applications.


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