Enhancement of Supercritical CO2 Inactivation of Spores of Penicillium oxalicum by Ethanol Cosolvent

Abstract

The inactivation of spores of Penicillium oxalicum by supercritical carbon dioxide (SC-CO2) was optimized by response surface methodology. The optimal inactivation conditions of 16.8 MPa, 49 degrees C, and 20 min were determined using ridge analysis, at which the predicted and experimental log(10) reductions were obtained as 5.74 and 6.12, respectively. The synergistic effect of a cosolvent (ethanol), which was used to modify SC-CO2, on the inactivation of the fungal spores was investigated. At less severe conditions of 10 MPa and 40 degrees C, I oxalicum spores of 10(7) CFU/ml were completely inactivated within 45 min by SC-CO2 modified with ethanol.