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Updated: May 12, 2025
Author Spotlight: Eco-Friendly Extraction of Bioactive Compounds Using Polyol-Based Microwave-Assisted Techniques
Published on: August 23, 2024
Microwave hydrodiffusion and gravity: A green extraction technology for phenylethyl isothiocyanate from watercress
Ana Sofia Sousa1, Sérgio Sousa2, Inês V Silva2
1Universidade Católica Portuguesa, CBQF - Centro de Biotecnologia e Química Fina - Laboratório Associado, Escola Superior de Biotecnologia, Rua Diogo Botelho 1327, 4169-005 Porto, Portugal; i3S-Instituto de Investigação e Inovação em Saúde, Universidade do Porto, 4200-135 Porto, Portugal; Institute of Molecular Pathology and Immunology of University of Porto, Ipatimup, 4200-135 Porto, Portugal.
Abstract:
Watercress is a cruciferous vegetable and the primary natural source of phenylethyl isothiocyanate (PEITC), a powerful health-promoting agent. Conventional extraction of PEITC relies on harmful solvents, which limits sustainability. This study introduces a novel, solvent-free method-microwave hydrodiffusion and gravity (MHG)-to extract PEITC from watercress by-products (WCBP). Results showed that freezing WCBP is fundamental for effective PEITC extraction via MHG. Using a three-level factorial experimental design, optimal MHG extraction conditions were determined (microwave power: 1.91 W g-1; extraction time: 29 min), yielding a PEITC content of 1818.26 microg g-1 WCBP (dry basis), along with extracts rich in polyphenols and possessing antioxidant properties. This work demonstrates that MHG is a sustainable method for extracting isothiocyanates, supporting a zero-waste approach since the clean residue from the extraction process can be reused to obtain new ingredients, thus enhancing resource efficiency and promoting a circular economy in the agro-food industry.
