Growth dynamics of Clostridium perfringens superdormant spores in cooked ground pork under synergic treatment of heat and hydrostatic pressure

[Display omitted] •Heat shock (HS) combined with hydrostatic pressure (HP) effectively induces the germination of C. perfringens spores.•When HS and HP are combined with heat treatment (HT), C. perfringens spore counts are reduced by a maximum of approximately 3.8 log10 CFU/mL.•C. perfringens superdormant spores grow more slowly in cooked meat compared to the original dormant spores.•The modified Gompertz and square root models effectively predict the growth of C. perfringens superdormant spores. ’Germination-inactivation’ strategy is recognized as an effective approach for the control of C. perfringens spores. However, the presence of superdormant (SD) spores limits the implementation of ’germination-inactivation’ strategy. To enhance the effectiveness of ’germination-inactivation’ strategy. We investigate the synergic effects of heat shock (HS) and hydrostatic pressure (HP) treatments—especially moderate-high hydrostatic pressure (mHP) and vigorous high hydrostatic pressure (vHP), followed by heat treatment (HT) to eliminate the germinated spores. The optimal treatment duration for both mHP and vHP was determined to be 20 min. which effectively germinated most of the original spores but leaving 3 log10 CFU/mL of superdormant spores after treatment. Flow cytometry and phase-contrast microscopy demonstrated spores’ heterogeneity and classified spores into four subpopulations, allowing successful isolate of superdormant spores. Super-dormant spores (mHP-SD and vHP-SD) were then inoculated into cooked pork and stored at various temperatures (20, 25, 30, 36, and 45 °C), with the original dormant spores (D) serving as the control. Result shows that both super-dormant spores showed lower maximum specific growth rates (μmax), longer lag phases (λ), and extended assessment periods compared to the original dormant spores, regardless of storage temperature. Additionally, the modified Gompertz model (GOM) and the square root model were validated as effective primary and secondary predictive models for the growth kinetics of various C. perfringens spore types. This study shows the effectiveness of a synergic treatment of HS and HP in controlling C. perfringens and the growth dynamics of its SD spores, providing an innovative approach to controlling spore-forming pathogens.