Development of a new process for wine dealcoholisation using supercritical CO₂ extraction-distillation coupling

Abstract

The global wine sector is currently facing a significant crisis driven by declining consumption and changing consumer preferences. In this context, fully dealcoholised wines emerge as a promising diversification strategy to adapt to new markets and consumption patterns. Current processes, such as membrane separation or vacuum distillation, do not generate a finished product with good olfactory qualities because there is a lack of selectivity between alcohol and aromas and the use of exogenous aromas became a common practice. The purpose of our work is to develop a process that combines distillation and supercritical CO2 (scCO2) extraction to produce a dealcoholised wine with an alcohol by volume content below 0.1% v/v. Studies showed that the aroma extraction by scCO2 extraction enabled the obtention of high-quality aromatic extract. Thanks to this selective process, the aroma fraction recovered could be reintroduced into the dealcoholised wine, significantly reducing the aroma loss occurring during other processes [1]. Various process couplings are being studied (distillation-distillation, distillation-scCO2 extraction, scCO2 extraction-distillation, scCO2 extraction-scCO2 extraction) using numerical simulation with ProSimPlus software (v3.7.10, Fives ProSim, Toulouse). Simulations are conducted on model wine composed with nine volatile molecules representative of the main aromatic chemical families present in wine (alcohols, carbonyl compounds, acetates, ethyl esters, volatile phenols, monoterpenes and sesquiterpenes). The first results of process simulation for the distillation-distillation coupling, based on the thermodynamic behaviour of the mixture, showed that the alcohol could be completely removed from wine while preserving most of the aroma compounds. However, specific aromas like acetates or carbonyl compounds could not be effectively separated from ethanol and therefore preserved. Although no sensory studies have been conducted, this loss is likely to directly influence the sensory profile of the product and highlights the obstacles associated with current processes. Therefore, the combination of distillation and scCO2 extraction whose study is still under progress could improve the preservation of these missing aromas and improve overall quality. The optimal operating conditions for this innovative combined process are being identified through simulations and will be subsequently validated and refined based on additional experimental results.

References

[1] Geffroy, O.; Morère, M.; Lopez, R.; Pasquier, G.; Condoret, J.-S. (2020). Investigating the Aroma of Syrah Wines from the Northern Rhone Valley Using Supercritical CO2-Dearomatized Wine as a Matrix for Reconstitution Studies. J. Agric. Food Chemistry, 68(41), 11512‑11523.