The effect of heat treatments coupled with high pressure on Clostridium sporogenes putrefactive anae4robe spores in a model system was stuided. A meat broth used as model system was sterilised and inoculated with spores of Clostridium sporogenes putrefactive anaerobe 3679 ATCC 7955 (2 x 10~6 spores/ml). The inoculated meat broth (2.5 ml) was packaged in sterilised PE vials. The vials were kept at 0 deg C until processed. The packages were subjected to pressures from 600 to 800 MPa and the processing time was up to 20 min using an experimental press (the ABB QFP 15000 high pressure food processor). The temperatures of the samples (from 90 to 110 deg C) were kept constant during the process using an internal control system placed into the press vessel. The processed samples were aseptically opened and the surviving spores were counted using TSC Agar Base (OXOID). The plates were incubated at 30 deg C for 7 d under anaerobic conditions. "D" and "z" values were calculated for various processing pressures (600, 700 and 800 MPa). The "D" values decreased from 1.28 to 0.69 min as the processing pressure increased from 600 to 800 MPa. The "z" values increased from 16 to 17.9 deg C as the processing pressure increased from 600 to 800 MPa. The heat treatment in combination with high pressure appears to be as effective or better than thermal processing alone (D_(120)=1.9', z=11.8 deg C at ambient pressure). From these results it has been possible to establish a relation between time, temperature and pressure. This relation is able to calculate the D value at known pressure and temperature in a predictive way. This relation seems to have a good correlation with reality. Its use will allow the calculation and prediction of the effect of any processing at high pressure conditions for Clostridium sporogenes putrefactive anaerobe 3679 ATCC 7955. Further studies are performed to verify and optimise the relation founded.
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