|
The Chinese take-out was great, but it's now 2 a.m. and
you've got a serious case of vomiting and diarrhea. Could it
have been the fried rice? Quite possibly, and the culprit is
often a bacteria called Bacillus cereus.
B. cereus comes in different forms. One of these forms is
frequently found in uncooked rice. This form is particularly
hardy and can survive cooking. If the cooked rice is then held
at room temperature, the surviving bacteria may multiply and
produce a heat-stable toxin that can survive acidic conditions
and brief reheating, such as in stir frying.
In Oriental restaurants, large batches of rice are
frequently left to cool at room temperature. Refrigeration is
said to make the rice sticky, yielding a less desirable fried
rice product, so rice is cooled at room temperature. This
cooling, especially if prolonged, creates ideal conditions for
the organism to grow and create a toxin.
As an example, in one outbreak involving a catered lunch
served to children in two day care centers, cooked rice was
cooled to room temperature before being placed in the
refrigerator. The next morning it was pan-fried in oil with
pieces of cooked chicken and delivered to the day care centers
where it was held for one and one-half hours before being served.
Within six hours 14 of the 67 children and staff who ate the
fried rice became ill with nausea, vomiting, abdominal cramps and
diarrhea. B. cereus was isolated as the culprit. What was
disturbing was that neither the day care staff nor the restaurant
food handlers were aware that cooked rice was a potentially
hazardous food.
Luckily, B. cereus food poisoning usually only lasts six to
24 hours and is seldom associated with long-term complications.
Regardless, any form of food poisoning is best avoided.
How does one avoid B. cereus food poisoning? Treat cooked
rice as you would a cooked meat product. Refrigerate leftovers
promptly in shallow containers to encourage rapid cooling. If
you're cooking rice for use later in fried rice, refrigerate the
cooked rice in shallow containers within one hour of preparation.
Keep cooked rice refrigerated until ready to stir fry. Once
prepared, keep fried rice hot (above 140 degrees Fahrenheit)
until ready to serve.
For more information, contact your local
Colorado State University Extension office.
|
