Modeling the inactivation kinetics of Bacillus coagulans spores in tomato pulp from the combined effect of high pressure and moderate temperature

High hydrostatic pressure processing (HHP) have been widely studied as a means to reduce and/or eliminate microbial spoilage and the presence of pathogenic microorganism. The present study evaluated the combined effect of HHP and moderate temperature on inactivation kinetics of Bacillus coagulans spore in tomato pulp. Pressures from 300 to 600 MPa and temperatures of 50 and 60 degrees C were applied. Inactivation kinetic parameters were obtained through the application of a primary biphasic model and classical secondary models to describe the influence of pressure and temperature on spore inactivation. Processes of 300 MPa combined with temperatures of 50 and 60 degrees C showed 2 and 2.4 log reductions, respectively, after 15 min of treatment. For processes at 600 MPa and 50 or 60 degrees C temperatures with the same holding time, the reductions were 3.1 and 5.7 log reductions, respectively. These findings illustrate the improved efficiency of HHP with the application of moderate temperatures on the inactivation of B. coagulans spores, and how variations in pressure and temperature impact the effectiveness of the process. Results shown in this study may help in the design of processes for food preservation based on HHP technology. (C) 2013 Elsevier Ltd. All rights reserved.