Inactivation of bacillus cereus ATCC 14579 spore on garlic with combination treatments of germinant compounds and superheated steam

Abstract

Garlic is one of the most popular spices in the food industry because of its unique flavor, aroma, and health benefits. However, garlic is easily contaminated by spore-forming Bacillus cereus from the soil. We studied inactivation of B. cereus spores using superheated steam (SHS) and germinant compounds such as L-alanine, inosine, and disodium 50-inosinate. Treatment with SHS and germinant compounds (50 mM L-alanine plus 5 mM disodium inosine 50-monophosphate) on B. cereus spores was more effective than SHS treatment alone. The inactivation trends were analyzed using the Weibull model, and a time required to achieve a 3-log reduction was determined. These values at 1208C after SHS and germinant compounds plus SHS were 2.14 and 1.26 min, respectively. In addition, SHS and germinant compounds plus SHS treatments inactivated B. cereus ATCC 14579 spores effectively without causing sublethal injury. Levels of inactivation of B. cereus spores enumerated on mannitol–egg yolk– polymyxin and overlaid with Brilliance Bacillus Cereus were not significantly different for all treatment conditions. Therefore, germinant compounds plus SHS treatment can be used effectively to control B. cereus ATCC 14579 spores on garlic.