Inactivation of yeasts in grape juice using a continuous dense phase carbon dioxide processing system

The effects of dense phase CO₂ processing parameters, including temperature (25 and 35°C), CO₂ concentration (0, 85 and 170 g kg^-1) and pressure (6.9, 27.6 and 48.3 MPa), on yeast survival and sensory properties of grape juice were investigated. The dense phase CO ₂ process resulted in more than a 6 log reduction in yeast population. As the CO₂ to juice concentration, temperature and pressure increased, the inactivation rate increased. CO₂ in the supercritical state was more effective in inactivating yeast than in the subcritical state. The process did not cause detectable flavor degradation. Dense phase CO₂ processing can be an effective non-thermal alternative process for pasteurization of grape juice.