The reason you can't and shouldn't reheat rice is because of the potential to have the growth of a bacteria called Bacillus cereus which is also known as fried rice disease.
The Bacillus cereus bacteria is commonly found in dust and soil as well and can produce spores which can survive during the cooking and reheating process of the rice.
Fried rice disease which is also known as fried rice syndrome is a type of food poisoning caused by bacteria called Bacillus cereus.
Bacillus cereus is a kind of bacteria which forms spores which release harmful toxins.
One of the most common bacteria found in fried rice is Bacillus cereus.
It is a spore-forming bacterium also commonly found in soil and the environment.
It is quite rare to get sick with fried rice disease, especially when compared to other foodborne bacteria such as salmonella.
In the U.S.,there are about 63,000 cases a year, and in Canada, about 36,000 cases — which is relatively negligible, compared to other bacterial illnesses.
Intestinal Bacillus cereus infections are common in many countries and often mild.
About 63,400 outbreaks of B. cereus occur each year in the United States,
If you eat rice that contains Bacillus cereus bacteria, you may be sick and experience vomiting between 30 minutes to 6 hours after, or diarrhoea 6 to 15 hours afterwards.
Symptoms are relatively mild and usually last about 24 hours.
Fried rice syndrome is the vomiting type.
The incubation time of fried rice syndrome is very short, and the symptoms usually kick in within one to six hours after ingesting the contaminated food.
These symptoms include nausea, vomiting, and abdominal pain.
Symptoms of fried rice syndrome can be uncomfortable, but they're typically self-limiting and resolve within 24 hours,
Just remember that it's essential to stay hydrated, especially if you're experiencing vomiting or diarrhea.
To avoid the risk of fried rice syndrome you should serve rice as soon as it's been cooked.
If that's not possible, cool the rice as quickly as possible (ideally within 1 hour).
Keep rice in the fridge for no more than one day until reheating.