Linear tuning of microwaves power for the extraction of bioactive molecules from citrus peels

In the last years, an alternative and convenient way to composting and/or bio-gasifying food waste is represented by the extraction of high value bioactive components from such materials. In particular, essential oils contained in matrices such as orange or lemon peels may represent high value bioactive components for the nutraceutical and pharma industry. In recent years, microwave assisted processes have been considered for use in solvent-free extraction. However, the microwave assisted extraction is often performed in very simple microwave systems, without an accurate control, if any, of the power release.In this work, the linear tuning of microwave power for the extraction of bioactive components from citrus peels is discussed, with emphasis on the consequent process yield and extract characteristics. Chemical analysis of the extracted mixture showed the presence of quite a number of active molecules of relevant interest for pharmaceutical and nutraceutical industries, such as glycoside flavanone (Hesperidin and Eriocitrin) in lemon peels, and polymethoxylated flavones (Nobiletin and Sinensetin) in orange peels.