Herein we investigate the effect of multi-pulse high hydrostatic pressure (MP-HHP) on the inactivation of Bacillus subtilis spores. B. subtilis spores were subjected to MP-HHP under pressures at 200-500 MPa at temperatures of 40 and 60°C with 3 pulses (holding time of 3 min) with a total processing time of 10min and compared it with a single pressurization (S-HHP). Mechanism of spore inactivation by S-or MP-HHP was explored by assessing germination by heat shock treatment, spore susceptibility to lysozyme and hydrogen peroxide (H2O2), release of dipicolinic acid (DPA), and the permeability of inner membrane and cortex. Our results presented the highest spore inactivation (5.8 log reduction), when MP-HHP was applied under the highest temperature and pressure. The increased inactivation appears to be largely due to mechanical disruption of spore coat and inner and outer membranes, as evidenced by DPA release, increased susceptibility to lysozyme and...

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