Assessing safety risks associated with Burkholderia gladiolus in soaked Auricularia auricula-judae: One instant...

Soaked Auricularia auricula-judae (A. auricula-judae) serves as a significant vehicle for foodbome disease caused by Burkholderia gladiol. This study aimed to develop predictive models that described the effect of temperature on the growth and bongkrekic acid (BA) toxin production of B. gladioli in soaked A. auricula-judae. The experiment involved inoculating soaked A. auricula-judae with B. gladioli and incubating it at 4, 10, 15, 20, 26, 30 and 36 °C. B. gladioli concentration data was used to develop a growth predictive model, while BA measurements were utilized to create a toxin predictive model. Model validation was conducted at 18 °C, 28 °C, and 33 °C. The results indicated that B. gladioli did not grow at 4 °C and 10 °C. The SGompertz model was identified as the most appropriate primary model, while a quadratic polynomial model was derived as a secondary model. The secondary model determined that the minimum temperature (T_min) required for the growth in soaked A. auricula-judae is 12.9 °C. Furthermore, the minimum detectable concentration of B. gladioli for qualitative BA production in soaked A. auricula-judae was approximately 8 log CFU/g, and a toxin-producing model has been developed to predict the time of BA production. Finally, the validation data obtained at 18, 28, and 33 °C showed RMSE and RE values of 0.30, 0.21, and 0.22 log CFU/g and - 2.2 %, -3.1 %, and - 2.5 %, respectively. This study revealed the growth kinetics of B. gladioli and provides information for the foodborne risk of bongkrekic acid production by B. gladioli on soaked A. auricula-judae.