Many people are accustomed to using rice cookers to keep food warm. They think that if the lid is tightly sealed and the power is continuously turned on to keep food warm, there will be no hygienic problems if the temperature is high enough. However, they do not know that this practice has hidden health risks.Xiong Zhujuan, chief physician of the Clinical Nutrition Department of Sichuan Cancer Hospital, reminded,Meals kept warm in a rice cooker for more than 4 hours can easily become a breeding ground for bacteria to multiply, and may even secretly produce harmful substances, threatening your health.
The World Health Organization clearly states that the "danger temperature zone" of food is 5°C to 60°C. This temperature range is the most suitable environment for pathogenic bacteria to breed, and most harmful bacteria will grow rapidly under this condition.
The heat preservation function of rice cookers is usually maintained at 60°C to 70°C. Although it seems safe, there are two major hidden dangers: First, uneven heating in the pot. When the upper layer of food comes into contact with the air, the temperature can easily drop below 60°C, directly falling into the dangerous temperature zone.
Second, secondary contamination is prone to occur. If the food has been eaten and the tableware is contaminated with saliva, pathogenic bacteria such as Staphylococcus aureus and salmonella will invade, and the number can double every 20 minutes at a suitable temperature.
Eating this kind of food that has been kept warm for a long time will cause abdominal pain, diarrhea and other discomforts in mild cases. In severe cases, it may cause acute gastroenteritis, accompanied by vomiting, diarrhea and other symptoms, seriously affecting physical health.
What is even more alarming is that keeping food warm for a long time will increase the risk of cancer. Green leafy vegetables contain natural nitrates, which are harmless to the human body when consumed normally. However, under the action of bacteria, nitrates are converted into nitrites. After entering the stomach, nitrites combine with protein decomposition products to form nitrosamines, a type of carcinogen recognized by the WHO, which is closely related to various cancers such as liver cancer, gastric cancer, and esophageal cancer.
The risky dose of a single consumption is low, but long-term and frequent consumption will continue to increase the metabolic burden on the liver, cause cell damage, and quietly increase the probability of cancer.Therefore, meals kept warm by a rice cooker must be consumed within 4 hours. If it is not expected to be finished in time, it should be refrigerated in time to prevent bacterial growth and health risks from the source.
