Irradiation of spores of Bacillus cereus and Bacillus subtilis with electron beams

The effect of irradiation with accelerated electrons on Bacillus cereus and Bacillus subtilis spore counts and spore heat resistance was investigated. Spore counts reduced approximately two log cycles for B. cereus and up to five log cycles for B. subtilis after a radiation dose of 7.6 kGy, with D10 values ranging from 1.5 to 3.8 kGy. Radiation had an important heat-sensitising effect on bacterial spores. After a 3.3 kGy treatment DT values were reduced more than three times for both B. cereus and B. subtilis spores. This study indicates the potential use of accelerated electrons, alone or followed by a heat treatment, for food preservation.