Inactivation of microorganisms by supercritical CO2 in a semi-continuous process

摘要

The anti-microbial effect of CO 2 in a semi-continuous experimental set-up was investigated and different values of temperature, pressure and treatment time were applied. Microorganisms were suspended in a phosphate buffer solution and inactivated under a continuous flow of supercritical CO2 (SC-CO2). Three microorganisms with different features were treated as models: S. cerevisiae, B. subtilis and S. marcescens. Exposure of the cells to SC-CO2 was investigated and the mass transfer and thermodynamics of a CO2-water system were studied by theoretical modeling. Results confirmed that the microorganisms considered were sensitive to the SC-CO2 treatment at mild temperatures and, showed that the semi-continuous experimental set-up is much more efficient than a batch one. The development of SC-CO2 pasteurization units for heat-sensitive foodstuff at the industrial level is proposed.