ECOFRIENDLY MICROWAVE-MEDIATED APPROACH FOR THE EXTRACTION OF BIOACTIVE COMPOUNDS FROM WASTE MATRICES IN THE AGRO-ALIMENTARY SECTOR

Microwave assisted extraction (MAE) is a relatively new class of extraction procedures which is gaining increasing interest mainly due to the smaller quantity of solvents employed, with respect to traditional techniques, together with microwave inherent advantages of being a rapid, volumetric and selective heating source, leading to considerable extraction time reduction and to a better extraction efficiency [1,4] In the present work different MAE techniques, such as solvent-free microwave extraction (SFME) and microwave hydro-diffusion and gravity (MHG), were exploited for the extraction of worn out plant matrices, such as grape marc (from the wine-making process) olive solide waste (from olive oil industry) and rose petals, leaves and stalks, (from rose syrup production). The aim was the development of an eco-sustainable microwave mediated extractive method to be applied to exhauste matrices in order to obtain new bioactive extracts with potential nutraceutical and cosmeceutical properties, leading to matrices with an added value as recycled sources. In order to optimise the MAE process employed to the particular target compounds, the design and development of customized microwave applicators is required. Numerical simulation and design of experiments (DoE) techniques will be highlighted as powerful tools in pursuing optimisation of extraction procedures, by allowing to achieve both highly efficient applicators design and proper processing condition with maximum yield. Examples of the designed microwave applicators and optimized extraction procedures will be presented.