Modelling the effects of food ingredients and pH on high-pressure processing inactivation of Bacillus cereus spores: a laboratorial study

P>The combination of high pressure and heat on Bacillus cereus spores in food matrix was investigated with the purpose of achieving a predictive model of microbial inactivation. The high-pressure processing (HPP) conditions were fixed at 540 MPa and 71 degrees C for 16.8 min, which were determined as the optimum conditions considering six-log-cycle reductions of B. cereus spores. The effects of soybean protein, sucrose, soybean oil and pH on the inactivation of B. cereus spores by HPP were evaluated, and a quadratic predictive model for the effects of food ingredients and pH on the reductions of B. cereus spores by HPP was built using response surface methodology. The experimental results showed that soybean protein, sucrose and pH significantly affected the reductions of B. cereus spores. The predictive model is significant, because the level of significance was P < 0.0001 and the calculated F-value is much greater than the tabulated F-value. The adequacy of the predictive model equation was verified effectively using the experimental test data that were not used in the development of the model.