Waste from olive oil production, such as olive leaves, is a potential source of high-value phenolic compounds. This study evaluated the extraction of these compounds using natural deep eutectic solvents (NADES) as a sustainable alternative.
Seven NADES were tested in comparison with conventional extraction with 70% ethanol, identifying oleuropein, luteolin-7-O-glucoside, and verbascoside as the main bioactive compounds present in the extracts. The extracts based on glycine and lactic acid showed higher polyphenol content, while those based on choline chloride and oxalic acid exhibited the highest antioxidant activity.
The study confirms that NADES are a sustainable and highly efficient alternative for recovering polyphenols from olive leaves. However, it is necessary to evaluate the safety of the extracts for their incorporation into food formulations.
The results were published in a poster at the International Conference on Sustainable Foods, held on 24 and 25 July.
