Inactivation of Bacillus cereus Spores on Stainless Steel by Combined Superheated Steam and UV-C Irradiation Treatment.

Bacillus cereus spore contamination on food contact surfaces is of great concern in the food industry. Thus, in the present study, superheated steam (SHS) was used alone or combined with UV-C irradiation for inactivation of B. cereus spores inoculated on stainless steel coupons. Temperatures higher than 250°C were needed to effectively inactivate B. cereus spores by SHS treatment alone, while a synergistic bactericidal effect resulted from the sequential treatment of SHS before or after UV-C irradiation. The increased dipicolinic acid ratio obtained by the combined treatment had a significant role in the synergistic bactericidal effect. Therefore, the combined treatment of SHS and UV-C could be used effectively to inactivate B. cereus on stainless steel. It is recommended to use hurdle technology with reduced energy consumption to ensure microbiological safety on food contact surfaces.