According to the National Health Service of UK, reheating food can cause food-poisoning depending on the way it’s stored. Uncooked rice can contain spores of Bacillus cereus, a bacterium that can cause the illness. When the rice is cooked, the spores can survive but if left at room temperature, the spores can grow into bacteria. These bacteria can multiply and may produce toxins that cause vomiting and/or diarrhoea. The longer the cooked rice is left at room temperature, the more likely it is that the bacteria or toxins could make it unsafe to eat.
Chicken
Chicken is one of the most commonly reheated foods but also the most dangerous to due to the high content of protein in it. Reheating it after a day or two can cause digestive problems. If it has to be eaten after a few days, it’s best to be consumed alone.
Mushrooms
These should be eaten right after preparation. Their composition of proteins can change after a day or two, so it can be harmful for the digestive system to consume them later. Mushrooms should be eaten cold or removed from the dish that is to be reheated.
Spinach
Reheating spinach is dangerous too since it comprises a high level of nitrates that, when reheated, cause the whole amount of spinach to become a complete nitrate. Spinach and other leafy vegetables contain high concentrations of nitrate. Nitrate itself is harmless, but can be converted to nitrites and then to nitrosamines, some of which are known to be carcinogenic.
Eggs
This breakfast staple becomes toxic when exposed to high heat. So, avoid reheating scrambled or boiled eggs. The protein present in eggs gets destroyed when exposed to heat over and over again.
Potatoes
Potatoes are nutritious but they lose their nutritional value if you let them be at room temperature for long. They can actually become toxic and cause illnesses, such as food-poisoning.
Cooked green vegetables
Vegetables, such as beets, spinach, lettuce, cress and celery, are rich in nitrates, which are beneficial to the body. Reheating them can turn them into nitrites and, in turn, into nitrosamines, as previously mentioned. These are known to be carcinogenic, so avoid reheating them after left for a few days.
