Bacillus cereus is a gram-positive spore-forming bacterium and produces an emetic or diarrheal syndrome induced by an emetic toxin and an enterotoxin, respectively. In this study, the effect of different types of media, temperature, and time on the sporulation of B. cereus, and thermal resistance of B. cereus spores produced in various temperatures were evaluated. The highest levels of spores were detected when they are produced at 25℃. There were no significant differences in levels of spores produced at 25℃ among culture media and times while levels of spores produced at 43℃ were significantly reduced with the increase of time. However, thermal resistance of B. cereus spores could be affected by incubation temperature. In fact, higher D-values (12.0, 10.1, and 5.9 min for 2, 4, and 6 weeks, respectively) of spores produced at 43℃ were observed than did in samples produced at other temperatures (25 and 37℃). D-values of spores were 7.7, 8.2, and 12.0 min when they were produced at 25, 37, and 43℃ for 2 weeks, respectively. The sporulation of B. cereus at 25℃ could result in high amounts of spores however the sporulation at 43℃ for 2 weeks could be effective to produce thermal resistant spores.

The aim of this study is to evaluate the estrogenic activity of Cucurbita pepo seed extract which includes β-sitosterol and other phytosterols. Sample was extracted from Cucurbita pepo seed by supercritical carbondioxide method and resuspended with ethanol. Estrogenic activity was measured by recombinant yeast assay which detects estrogenic activity using recombinant yeast with high level of estrogenic receptor. However, estrogenic activity of pumpkin seed extract was not found in this study. Based on this data, pumpkin seed extract will not cause estrogenic disturbance.