Investigation of desirable hydrostatic pressure required to sterilize Bacillus stearothermophilus IFO 12550 spores and its sterilization properties in glucose, sodium chloride and ethanol solutions

Desirable hydrostatic pressure required to sterilize Bacillus stearothermophilus IFO 12550 spores and its sterilization properties in glucose, sodium chloride and ethanol solutions were investigated. Spores were inactivated as treatment temperature (35 to 95 degreesC) increased at 50 and 100 MPa. The Pt (pressure z) values were 29.32 MPa under the pressure ranged from 10 to 60 MPa and 545.6 MPa in under 60 to 100 MPa at 95 degreesC. Therefore, 60 MPa was the desirable pressure to sterilize the spores at 95 degreesC. Glucose, sodium chloride and ethanol respectively decrease the inactivation rate of the spores significantly (P < 0.05) except for 6% glucose. The spores were inactivated at 60 MPa, 95<degrees>C for 420 to 540 min in the media with various food additives. The PD (pressure D) values ranged from 75.2 min (containing no food additives) to 86.2 min (containing 20% ethanol). (C) 2000 Elsevier Science Ltd. All rights reserved.