Did you know? Revealing 8 types of leftover foods that should not be eaten
We are now all advocating for a healthy diet, and it is not recommended to eat too much for dinner. However, this poses a problem for those who cook. It's not worth making too little, but if you make too much, leftovers are inevitable. This raises a new question: when it comes to leftovers from the night before, can they be eaten the next day?
1. Overnight tea should not be drunk
Because overnight tea has been left for too long, most of its vitamins have been lost. Moreover, proteins, sugars, and other substances in the tea will become nutrients for the breeding of bacteria and molds. Therefore, it is generally believed that overnight tea should not be consumed.
2. Can overnight Tremella (silver ear fungus) be eaten?
Tremella soup is a high-nutrition health supplement, but after being left overnight, its nutritional content decreases and harmful substances are produced. This is because both indoor-cultivated and wood-cultivated Tremella contain a high amount of nitrates. After being cooked, if left for a long time, bacteria will break down the nitrates, reducing them to nitrites.
When a person drinks this soup, nitrites naturally enter the bloodstream. The red blood cells in the blood contain hemoglobin, which can carry large amounts of oxygen to meet the body's needs.
However, nitrites have the opposite effect. They oxidize the body's normal hemoglobin into methemoglobin, causing it to lose its ability to carry oxygen and resulting in a lack of normal hematopoietic function in the body!
3. Even overnight boiled water cannot be drunk?
Boiling tap water for 3 to 5 minutes minimizes the content of harmful substances such as nitrates and chlorides, making it most suitable for drinking.
Drink less overnight boiled water: Nitrites can form carcinogenic nitrosamines in the body. Experts have found that the nitrite content in boiled water is higher than in raw water.
Furthermore, repeatedly boiling water for too long or water that has been boiled for more than 24 hours will have a significantly increased nitrite content. After being left for 24 hours, the nitrite content in boiled water is 1.3 times that of freshly boiled water.
Chinese people have a habit of drinking boiled water. It is best to boil and drink it fresh, or only drink the boiled water from the same day. Do not drink water that has been boiled for too long.
4. Can overnight eggs not be eaten?
Overnight eggs, can they be eaten?
Northerner: Yes, don't you see tea eggs sold everywhere on the street!
Southerner: No, especially for men, because it can cause hernias and swollen testicles!
Scientist: Not necessarily! If the egg is not fully cooked, the uncooked yolk, if eaten overnight, can easily breed bacteria if not stored properly, which can be harmful to health, causing issues such as stomach discomfort and bloating. However, if the food (egg) is already fully cooked and properly sealed and stored at a low temperature (generally refrigeration temperature), it can generally be safely stored for up to 48 hours.
From the scientist's advice, we can understand: whether overnight eggs can be eaten depends not just on whether they are reheated, but on whether they were fully cooked the first time they were boiled. Only after being fully cooked the first time can overnight eggs be reheated and eaten without problem.
Tea eggs are made using this principle. Many people may not know that tea eggs are boiled twice. The first time they are boiled until cooked, and the second time the shells are cracked, and tea and other seasonings are added before being boiled again. Therefore, tea eggs are definitely cooked. Now, some people like to eat half-cooked eggs (with a semi-liquid yolk). Those eggs should not be eaten overnight, even if they are cooked a second time.
5. Do not eat overnight leafy green vegetables
Because some leafy green vegetables contain a high amount of nitrates, if they are cooked and then left for too long, bacteria will break down the nitrates, reducing them to nitrites, which are carcinogenic and cannot be removed by reheating.
Generally, stem and leaf vegetables have the highest nitrate content, followed by gourds, with root and stem vegetables and cauliflower-type vegetables in the middle. Therefore, if you buy different types of vegetables at the same time, you should eat the stem and leaf varieties first, such as Chinese cabbage and spinach.
If you plan to cook extra food to reheat the next day, you should try to make fewer stem and leaf vegetables and choose gourds instead.
6. Do not eat overnight homemade braised and marinated foods
Braised and marinated foods are popular seasonal dishes among Shanghai residents. Many people also like to put leftover braised and marinated foods in the refrigerator "for the night," but this practice poses a significant food safety hazard.
To prevent food poisoning, do not eat overnight braised and marinated foods during the spring and summer seasons.
Unpackaged braised foods should be finished on the same day and not left overnight. From a food safety perspective, this is unhygienic. If possible, it is best not to eat overnight marinated foods.
Food experts remind us that even food stored in the refrigerator is not absolutely "safe." Molds and psychrophilic bacteria can easily grow in refrigerators.
7. Seafood cannot be eaten overnight
Leftover foods that should not be eaten include fish, seafood, leafy green vegetables, and cold dishes.
When fish and seafood are left overnight, they can easily produce protein degradation products that can damage liver and kidney function.
Leafy green vegetables contain varying amounts of nitrates. If cooked for too long or left for too long, not only will the vegetables turn yellow and change flavor, but the nitrates will also be reduced by bacteria into toxic nitrites, which have carcinogenic effects.
Cold dishes are often contaminated during preparation. Even if refrigerated, they are very likely to have spoiled after being left overnight and should be made and eaten fresh.
8. What to do with overnight soup?
Cantonese people love to simmer soups. Leftover soup is put in the refrigerator and then reheated the next day. Is this overnight soup good for your health?
Healthy way to eat:
The best way to store soup is to not add salt or other seasonings to the base. After cooking the soup, use a clean spoon to scoop out the portion to be consumed that day. For the leftovers, it is best to store them in a clay pot in the refrigerator.
This is because storing leftover soup in aluminum or stainless steel pots for a long time can easily cause chemical reactions. It should be stored in glass or ceramic containers.