Microbial Inactivation under High-Pressure Carbonation

Abstract

The effects of temperature and concentration of dissolved CO₂ on the death kinetics of Saccharomyces cerevisiae were demonstrated. Several combinations of pressures (4, 6, 8, 10 MPa) and temperatures (30, 34, 36, 38°C) were used. The D-values obtained were 0.14 min at 8 MPa and 38°C, and 0.15 min at 10 MPa and 36°C. The log D-values were related linearly to the treatment temperature and to the dissolved CO₂ concentration. The thermal resistance constant was 9.5°C, and the CO₂ resistance constant was 7.2 γ. This work enables the estimation of the D-values at any temperature and any CO₂ concentration. Non-thermal inactivation of microorganisms would be realized by the present technique.