4-Ethylphenol and 4-ethylguaiacol depletion in wine using esterified cellulose

► Esterified cellulose fibres were tested to deplete volatile phenols in wine. ► Cellulose acetate propionate was the most effective, 4g/l reduced phenols of 30%. ► Wine treatment did not affect colour and polyphenol content and improve quality. ► The polymer is regenerable without notable changes in depletion efficiency. ► The study opens up interesting prospects for cheap treatments of defective wines. The ability of cellulose acetate, cellulose acetate propionate (CAP), cellulose acetate butyrate and cellulose propionate (CP) fibres to reduce 4-ethylphenol and 4-ethylguaiacol, causing the off-flavour named “Brett character”, was studied. CAP and CP performed best in a preliminary comparative test. The former was chosen because of its more favourable FDA classification for food contact substances. CAP effectiveness was studied in relation to the reduction in volatile phenols with doses of up to 20g/l and wine contact times of up to 60min. Using 4g/l, reduction of both phenols was, on average, 31–32% in defective red wines. Wine treatment affected neither colour nor total proanthocyanidins and catechins, and wines were judged to be better than the corresponding spoiled controls. CAP fibre can be regenerated by washing with ethanol or aqueous solution (pH 12), without notable changes in depletion efficiency. The technological characteristics of CAP and, to a lesser extent, CP offer interesting prospects for producing filtration beds, pads and membranes for the treatment of wines and beverages affected by “Brett character”.