Purpose: The purpose of this study was to evaluate the survival characteristics of B. cereus spores throughout the noodle manufacturing steps and cooking.
Methods: B. cereus spore cocktail of 5 strains was added when preparing dough, and resulted in 5 log CFU/g concentration. The dough was aged for 0, 1, 2, 4, 6 and 8 hours at 20, 25, 30, 35 and 40 °C. The number of spores was estimated at each manufacturing step and the survival of spores was evaluated with times (2, 4, 6, 8, 10 and 12 min) while the noodles were cooked at boiling water.
Results: The number of B. cereus was not significantly different with aging times and temperatures, which indicates no growth in wet noodle environment even though it may germinate. All spores in wet noodles without aging were destroyed after 12 min cooking and D110°C value was found as 1.8 min. After 1 hour aging, the cooking time was shortened to 10 min at 20 °C and reduced by 2 min with increase of aging temperature by 10 °C. This means that the higher aging temperature induces more germination of spores and results in faster destruction of B. cereus in wet noodles.
Significance: These results suggest that higher temperature may be applied for wet noodle aging to kill B. cereus faster during cooking and thus may not pose the risk of food poisoning.