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Name: Clarence A.
Status: Other
Age: 20s
Location: N/A
Country: N/A
Date: N/A 

I read somewhere that eating overnight rice is bad for you. It seems that the rice produce a toxin once it is left over night. Can you tell me more about this? Any truth in this?

I am not referring to spoilage but rather a 'toxin' that rice produces once left to stand overnight. I read this somewhere but I cannot remember where or the details of this. I think it has to do with the rice fermenting and producing a chemical that can be toxic if consumed. Anything on this?

It is true. I will look into the specific details, but what happens is that rice often contains hardy bacterial spores that can withstand the cooking process. Cooking the rice, however, awakens the spores and they become living, metabolizing bacteria once again. If the conditions are right for the bacteria to grow (say, if the rice is allowed to stand without refrigeration), the bacteria produce a toxin that causes diarrhea. This is sometimes called "fried rice diarrhea" because fried rice is often made with yesterday's steamed rice.

I will see if I can find the name of the specific bacterium responsible.

Richard E. Barrans Jr., Ph.D.
Assistant Director
PG Research Foundation, Darien, Illinois

Following up on my reply yesterday - the bacterium responsible is Bacillus Cereus.

Richard E. Barrans Jr., Ph.D.
Assistant Director
PG Research Foundation, Darien, Illinois

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