Lot of people, very often, prepare meals for several days. However, some foods then change their composition and lose their nutritional properties after reheating them and some can even become toxic.
It would be best if nothing is heating up, because every time you heat up the food comes to the different chemical reactions. Of course, not everything depends on reheating, but also on how long the food stands and whether it was in the fridge and kept properly, but imply, some food should never reheat.
The following foods are accredited by the Food Standards Agency and the European Food Information Council as foods which reheat should be avoided:
Reheating potato is not a problem by itself, as far as its storage after heat treatment.
If the potato is allowed to cool to room temperature, particularly if the aluminum foil is covered thereby, creates conditions for occurrence of the bacteria Clostridium botulinum.
Chicken, cooked and smoked fish (salmon, mackerel, cod), raw or lightly cooked shellfish, dairy products and foods made with milk, cheese and eggs are becoming high-risk foods after reheating if they are pre-treated on low temperatures. Chicken contains parasites Salmonella, so it’s not recommended to reheat it. Chicken meat has a higher density of red meat, but when reheating different proteins break down and can cause stomach problems also.
Mushrooms is best eaten immediately after preparation, but if stay for another day, it is better to eat them cold. This is true for soups, as well as the risotto, which is made with mushrooms. When warming mushrooms there is a change in the composition of protein, and even a change in taste. They then can cause a variety of gastrointestinal problems, and lose their health benefits.
Eggs is high-risk food for reheating which also becomes toxic due to exposure to high temperatures. It does not apply to foods where the eggs are scrambled in sauces such as béchamel, but refers to dishes with boiled or fried eggs.
Spinach and other types of leafy vegetables contain high concentrations of nitrates which under the action of microorganisms during reheating passes in very harmful and carcinogenic substances. Spinach is the most risky when it comes to reheating and yet it should be consumed freshly prepared.