New molecularly imprinted polymers for reducing negative volatile phenols in red wine with low impact on wine colour.

4-Ethylphenol (4-EP) and 4-ethylguaiacol (4-EG) formation in red wines by Dekkera/Brettanomyces yeasts reduce significantly wine consumer's acceptability. Polymers with specific adsorption for volatile phenols (VPs) could be a valuable tool for wine producers for removing this negative sensory defect. In this work, a new molecularly imprinted polymer (MIP) was synthesised using ethylene glycol dimethacrylate (EDMA) as cross-linker and ethylene glycol methyl ether acrylate as functional monomers. Although there was observed a competitive binding of the more abundant structurally related phenolic compounds of the wine matrix, it was still able to reduce 38 to 63% the wine VPs, depending on the wine VPs levels, presenting higher performance than the respective non-imprinted polymers (NIP). Sensory analysis of the MIP treated wine resulted in a significant decrease in the phenolic attribute and significant increase of the fruity and floral attributes, with no significant differences in the wine colour perceived by the expert panel. The sensory improvement of the MIP was significantly higher than that observed for the correspondent NIP.