Prediction of detection time of staphylococcal enterotoxin A formed in hydrated batter mix

Abstract

Staphylococcus aureus food poisoning is caused by the ingestion of staphylococcal enterotoxin (SE) produced in foods and SE type A (SEA) is the most common among many types. While SEA formation in hydrated batter mix can be a potential hazard in the production processes of foods, no information is available. Therefore, the growth kinetics of S. aureus and subsequent SEA formation in hydrated batter mix during storage were studied to estimate the detection time (DT) of SEA. At 30 °C and with different inocula (3–5 log CFU/g), SEA was detected when the population of S. aureus reached 5.5–5.9 log CFU/g in the samples. With an inoculum of 4 log CFU/g and isothermal storage between 14 and 34 °C, SEA was detected when the population reached approximately 6 log CFU/g. Therefore, the time to 6 log CFU/g was chosen to as the DT of SEA in the samples. With a kinetic model predicting the growth of S. aureus in hydrated batter mix, the DTs of SEA stored under both changing and constant temperatures were successfully predicted. These results suggested that the present kinetic model could predict the DT of SEA in hydrated batter mix during storage. Prediction of DT of SEA in batter mix would be useful information to prevent the outbreaks of staphylococcal food poisoning.