Growth and survival of heat-, cold-, and acid-stressed Salmonella Typhimurium and native bacteria on chicken wings during refrigerated storage and temperature abuse.

During food processing, Salmonella is frequently exposed to environmental stresses that may alter its growth and survival, thereby influencing food safety and accuracy of microbial risk assessment. This study investigated the behavior of Salmonella Typhimurium (ST), unstressed (USST), heat-stressed (HSST), cold-stressed (CSST), and acid-stressed (ASST) on chicken wings and developed models to predict shelf life during storage at 4, 10, and 20°C. At all temperatures, native bacteria (NB) grew and were modeled using a no-lag phase (primary) model and Ratkowsky square-root (secondary) model for chicken wing shelf-life prediction. At 4 and 10°C, the ST populations, stressed or unstressed, gradually declined, whereas full growth curves were observed at 20°C. At 4°C, USST and stressed ST followed linear survival kinetics and the D value of CSST was 3-4 d longer than those of USST, HSST, and ASST. At 10°C, USST maintained a linear decline trend, whereas all stressed ST declined nonlinearly with shape parameters greater than 1. These results suggested that stressed ST may have potentially developed a defense mechanism during low-temperature storage. At 20°C, stress influenced ST's lag phase, growth rate, and maximum population, particularly for ASST. These findings demonstrated that stress effects on ST behavior were temperature- and stress-dependent. The estimated ST kinetic parameters provide valuable information for understanding stress-induced changes in ST behavior and support future development of predictive models incorporating temperature and stress factors for microbial risk assessment.