In the past, experts have warned that eating leftover rice could cause a case of food poisoning. Cooking rice unfortunately doesn’t always destroy all the pathogens residing on it; there is also a higher risk of food poisoning when rice is left at room temperature.
Dr. Bejamin Chapman, North Carolina State University’s resident Food Safety Specialist, said in an interview that a pathogen, known as Bacillus cereus, is prevalent in dried rice. Although the pathogen is commonly found in soil and food, some strains can cause harm to humans.
According to Dr. Chapman, Bacillus cereus spores can survive on rice — even when cooked. If the rice is stored at room temperature after cooking, the spores can grow and propagate. As soon as these spores germinate, they release toxins which include those resistant to heat. Although it is not clear how many infection incidents of Bacillus cereus there are, a report suggest that it constitutes up to two percent of food-borne diseases.
A study published in Epidemiology and Infection stated that boiled rice must be kept hot (more than 63 degrees Celsius) or cooled immediately, and be placed in a refrigerator within two hours after cooking. Fried or boiled rice must not be kept in warm conditions, especially in the range of 15-50 degrees Celsius; this temperature is ideal for the bacteria to multiply.
Meanwhile, Dr. Donald Shaffner, Rutger University’s food scientist, warned that there are restaurants who cook a large batch of rice, then keep it at room temperature all day. The best way for these restaurants to fend food poisoning is to refrigerate rice leftovers two hours after cooking.
It is important to note that their are different kinds of rice, and some can be stored at room temperature without risking a case of food poisoning. Sushi rice, for instance, can be left out at room temperature due to its content, which includes vinegar. The acidic properties due to the vinegar make it impossible for bacterial growth.
Foods you must not reheat
While on the subject of leftovers, here is the list of the foods you must not reheat. These foods cause food poisoning, especially if they were incorrectly stored. Also stay safe by avoiding microwaves when reheating food.
Potatoes – Potatoes must be immediately refrigerated. If they are left to cool down at room temperature, a bacteria known as Clostridium botulinum may develop. It can lead to botulism; a rare disease that could lead to paralysis.
Mushrooms – Mushrooms must be consumed at least 24 hours after they are prepared. Mushrooms are rich in proteins, but proteins quickly deteriorate as soon as you slice the mushroom. It is safe to eat mushrooms if they are reheated at a high temperature.
Eggs – Eggs may be reheated, but it must be done properly. When reheating, eggs should reach an internal temperature of 74 degrees Celsius to ensure they are safe for consumption. It is wise to skip reheating eggs in the microwave if you do not have a food thermometer.
Chicken – Reheating chicken might lead to digestive problems. The protein composition of the meat may be altered during reheating.
Spinach, celery, and beets – Spinach, celery, and beets contain high levels of nitrates that can be carcinogenic when reheated. This happens when these foods are heated, stored, then reheated.