Changes in volatile composition and sensory attributes of wines during alcohol content reduction

Rocco Longo, John W Blackman, Peter J Torley, Suzy Y Rogiers, Leigh M Schmidtke

A desirable sensory profile is a major consumer driver for wine acceptability and should be considered during the production of reduced alcohol wines. Although various viticultural practices and microbiological approaches show promising results, separation technologies such as membrane filtration, in particular reverse osmosis, evaporative perstraction, and vacuum distillation represent the most common methods employed at the commercial scale to produce this wine. However, ethanol removal from wine can result in a significant loss of compounds such as esters that contribute positively to the overall perceived aroma. Such losses can reduce the acceptability of the wine to consumers and decrease their willingness to purchase wines that have had their alcohol level reduced. The change in aroma as a result of the ethanol removal processes is influenced by a number of factors: the type of alcohol reduction process, the chemical-physical properties (volatility, hydrophobicity, steric hindrance) of the aroma compounds, the composition of the non-volatile matrix (through π-π stacking), and the ethanol level. This review identifies and summarises possible deleterious influences of the dealcoholisation process and describes best practice strategies to facilitate the minimisation of the modifications to the original wine composition.