Tannin Extraction from Chestnut Wood Waste: From Lab Scale to Semi-Industrial Plant

The chestnut tree (Castanea sativa, Mill.) is a widespread plant in Europe whose fruits and wood has relevant economic impact. Chestnut (CW) rich high-value compounds that exhibit various biological activities, such as antioxidant well anticarcinogenic antimicrobial properties. These metabolites can be mainly divided into monomeric polyphenols tannins. In this piece of work, we investigated sustainable protocol to isolate enriched fractions the above-mentioned from CW residues. Specifically, sequential extraction protocol, using subcritical water, was used pre-fractionation step, recovering approximately 88% tannins 40% first second steps, respectively. optimized also tested at pre-industrial levels, treating up 13.5 kg 160 L solution with encouraging results. Ultra- nanofiltrations were further enrich recovered fractions, achieving more than 98% tannin content heavy fraction, whilst removed permeate achieved 752.71 mg GAE/gext after concentration (75.3%). Samples characterized by means total phenolic (TPC), activity (DPPH· ABTS·), composition (hydrolysable condensed). addition, LC-MS-DAD for semiqualitative purposes detect vescalagin/castalagin vescalin/castalin, gallic acid ellagic acid. developed valorization allows efficient fractionation recovery major polyphenolic components approach evaluates scaling-up.