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 degrees 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 CO2 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.