Effect of Potassium Bitartrate, (+)-Catechin and Wood Extracts on the Volatility of Ethyl Hexanaote and Octanal in Ethanol/Water Solutions

The volatility of wine aroma compounds can be affected by other components in solution. The aim of this work was to determine whether potassium bitartrate, (+)-catechin, and wood extracts influenced the activity coefficients of representative wine aroma volatiles in ethanol-water solutions. (+)-Catechin caused a small reduction in the activity coefficient of ethyl hexanoate in aqueous ethanol at 10-20 mL/100 mL, while octanal was affected by (+)-catechin and potassium bitartrate, suggesting that these components reacted with the aldehyde. Interactions between volatiles and macromolecules seemed to be the main source of flavour matrix interactions in wines, though specific interactions due to chemical properties of some volatiles also determine their impact on wine flavour.