Volatile phenols depletion in red wine using molecular imprinted polymers

Abstract

Wines can be modified by microorganisms during the ageing process, by producing off-flavours like volatile phenols (VP), leading to their deterioration, with great economic losses. The development of methods to recover wines affected by unwanted VP became an important target. Molecular imprinted polymers (MIPs) are synthetic materials with artificially-generated recognition sites for selective extraction of organic compounds from different matrices. In this work, two MIPs to remove unwanted VP from wines were developed and their effects were evaluated. Volatile compounds were determined by GC-FID and GC-IT/MS and phenolic compounds (non-coloured and anthocyanins) by HPLC-DAD. The treatment with MIP-4EG and MIP-4EP significantly reduced the content of 4-ethylguaiacol and 4-ethylphenol, respectively. Nevertheless, the changes observed in wine non-coloured and coloured phenolics and sensorial analysis indicate that their specificity and selectivity regarding off-flavours still needs to be improved.