Proposed approach for determining minimal pasteurization conditions for refrigerated processed foods by combined challenge tests and probabilistic analysis

In this study, to minimize the degradation caused by pasteurization in processed foods, pasteurization conditions of 98 °C were determined for the preservation of curry sauces inoculated with psychrotrophic Paenibacillus spores for 12 weeks at 10 °C, leading to a proposed approach. Paenibacillus spores underwent vegetative growth in some samples heated for 25 min. Probabilistic analysis predicted that 16–51 of the spores survived in those samples. The number of surviving spores that did not exhibit vegetative growth during 12-weeks of storage was estimated by comparing the ratio of the samples without vegetative growth to the cumulative probability of spore survival, with this number, estimated to be below 43 spores per sample. Theoretically, this value could be achieved by heating for 27.1 min at 98 °C equivalent. For challenge tests alone, samples should be heated for at least 31 min; however, combining challenge tests with probabilistic analysis could shorten the pasteurization time.