INNOVATIVE MICROWAVE-MEDIATED PROCEDURES FOR NADES SYNTHESIS AND GREEN EXTRACTION OF SUSTAINABLE COSMETIC INGREDIENTS FROM AGRI-FOOD WASTE

The aim of this research was the development of innovative eco-sustainable microwavemediated extractive procedures, using synthetic NADES (natural deep eutectic solvents), as eco-friendly solvents, to obtain new sustainable bioactive ingredients from beetroot stalks (an agri-food waste), according to the green extraction and circular economy principles. A selection of natural compounds acting as hydrogen bond acceptors (choline hydrochloride or betaine) and hydrogen bond donors (fructose, urea, or glycerol) were used to prepare NADES as the extraction solvents and to develop a new in situ procedure which allowed a contemporary NADES synthesis and matrix extraction. The botanical waste was treated in a dedicated microwave oven (multimode scientific prototype), as an alternative energy source, without any other organic solvent. The extracts were characterized from a quali-quantitative point of view, evaluating the total phenolic content and the radical scavenging activity for their direct use as active ingredients in cosmetic formulations. Results indicate that NADES microwave-mediated extractions allowed for a fast and efficient recovery of bioactive compounds from the worn-out matrix, providing very good stability to the complex. The in-situ procedure proposed can be used for preliminary analysis making work up easier