Adsorption properties of molecularly imprinted polymers designed for removal of smoke taint compounds from wine

The presence of elevated concentrations of smoke-derived volatile phenols (and their glycoconjugates) in wine after grapevine exposure to wildfire smoke can give wine unpleasant smoky and ashy characters. To date, options for remediation of ‘smoke taint’ are limited, therefore, this study evaluated the potential for a commercially developed molecularly imprinted polymer (MIP) to remove smoke taint compounds from wine. A single-solute adsorption study was conducted in model wine and demonstrated adsorption of guaiacol, phenol and m-cresol by a diverse range of binding sites on the MIP surface. The adsorption capacity of the MIP towards guaiacol was estimated to be 1.2 μmol/g, with a higher capacity and affinity estimated for m-cresol (being 1.7 μmol/g). When a fixed-bed column packed with MIPs was used to treat smoke tainted Chardonnay, rosé and Cabernet Sauvignon wines the MIP column removed up to 47 % of the volatile phenols present in wine (but not volatile phenol glycoconjugates), with no detrimental effect on wine colour density and phenolic composition. Experiments evaluating column break-through and the reusability of MIPs were also performed to further establish the application potential of MIPs for remediation of smoke taint in wine.