Factors affecting the occurrence of viable but non‐culturable state in Salmonella, Escherichia coli and Staphylococcus aureus during thermosonication and prevent it with sodium pyruvate

Abstract

AbstractConcerning potential food safety and/or public health risks raised by viable but non‐culturable (VBNC) state bacteria, factors affecting its occurrence during thermosonication were summarised. The relative ratios of Salmonella and Escherichia coli in the VBNC state were higher than that of Staphylococcus aureus, suggesting that the tested gram‐negative bacteria would be more likely to survive in this state than S. aureus (gram‐positive). The culturability of bacteria was easier to be retained in neutral pH environment, resulting in a reduced likelihood of entering into a VBNC state. Non‐occurrence of a VBNC state by moderate heat of 32–57 °C was observed, facilitated in combination with sonication and being correlated with thermosonication conditions. Adding sodium pyruvate before thermosonication treatments could prevent the occurrence of a VBNC state, though the molecular mechanism of it is not clearly known and needs further elucidation.