Abstract
A rapid and simple method was developed for the determination of emetic toxin (CER; cereulide) produced by Bacillus cereus
in processed foods. CER was extracted using 70% hydrated acetonitrile and n-hexane. The n-hexane layer was separated and
evaporated. The residue was redissolved in acetonitrile and defatted with n-hexane saturated with acetonitrile, and The acetonitrile
layer was then analyzed using LC-MS/MS. To validate this method, foods that cause food poisoning by B. cereus, including cooked
rice, fried rice, pilaf, and pasta, were spiked with 1 ng/g or 100 ng/g CER, and recovery test were performed. CER recovery rates
from these 4 processed foods were 75%–92% at 1 ng/g, and 70%–91% at 100 ng/g with satisfactory repeatability and all other
parameters. It was possible to detect CER in fried rice about 6 hours after inoculation with B. cereus.
