8 Foods That Can Cause Problems When Eaten Overnight
Introduction: Wasting food is a desecration of it. To avoid leftover food, many people will save the food from the evening to enjoy the next day. However, not all foods can be eaten overnight. Even if you have stored the food in the refrigerator at a low temperature, some foods can cause big problems if eaten carelessly overnight!
1. Seafood
Foods that should not be eaten overnight include fish, seafood, green leafy vegetables, and cold salads.
Fish and seafood can easily produce protein degradation products overnight, which can damage liver and kidney function. Green leafy vegetables contain varying amounts of nitrates. If overcooked 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 are carcinogenic. Cold salads are more contaminated during processing, so even if refrigerated, they are likely to have spoiled overnight and should be eaten fresh.
2. Family-style 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 "overnight," but this practice poses significant food safety hazards. To prevent food poisoning, do not eat leftover braised and marinated foods overnight during spring and summer.
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's best not to eat leftover marinated foods. Food experts remind us that even food stored in the refrigerator is not absolutely "safe." The refrigerator is a place where molds and psychrophilic bacteria can easily grow.
3. Undercooked Eggs
Many trendy people nowadays like to eat undercooked eggs, believing that semi-liquid, incompletely cooked eggs will not destroy their nutritional value. However, raw eggs contain many bacteria and viruses, and the nutritional difference between fully cooked and undercooked eggs is not significant. Moreover, undercooked eggs are particularly prone to bacterial growth overnight, causing gastrointestinal discomfort, bloating, and other issues.
Someone might ask, "Isn't tea egg just boiled one day and sold the next day?" But tea eggs are boiled twice during the production process: first, they are boiled until cooked, then the shells are cracked and various seasonings like tea are added for a second boil. If the eggs are already fully cooked, they can be eaten the next day if stored properly in a sealed container at a low temperature.
4. Overnight Tea
Because overnight tea has been steeped for too long, most of its vitamins are lost, and the proteins and sugars in the tea become nutrients for the growth of bacteria and molds. Therefore, people generally believe that overnight tea should not be drunk.
5. Overnight Boiled Water
Boiling tap water for 3-5 minutes minimizes the content of harmful substances like nitrates and chlorides, making it most suitable for drinking.
Although the water has been boiled thoroughly, it is still advisable to drink less overnight boiled water because nitrates can form carcinogenic nitrosamines in the human body. Experts have found that the nitrate content in boiled water is higher than in raw water. Furthermore, the nitrate content significantly increases in water that has been boiled repeatedly for too long or for more than 24 hours. After being left out for 24 hours, the nitrate content in boiled water is 1.3 times higher than when it was first boiled. Chinese people have a habit of drinking boiled water. It is best to boil and drink it fresh or only drink the water from the same day, and avoid water that has been boiled for too long.
6. Overnight Tremella (Silver Ear Mushroom)
Theoretically, any food with high nutritional value should not be eaten overnight. Not only do the nutrients decrease, but it also easily becomes a breeding ground for bacteria. The same goes for tremella soup. Both cultivated and wild tremella contain a lot of nitrates. After cooking and bacterial decomposition, the nitrates are reduced to nitrites. If consumed on the same day, the nitrites can 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, overnight tremella causes the nitrites to have the opposite effect, oxidizing the body's normal hemoglobin into methemoglobin, which loses its ability to carry oxygen, leading to a lack of normal hematopoietic function.
7. Overnight Leafy Green Vegetables
Vegetables from the same day are best eaten on the same day and not left until the next day. Besides being unappetizing, these overnight leafy greens not only lose their nutrition but also produce pathogenic nitrites. Although refrigeration can reduce the nitrate content, over time, the nitrite content will still increase. Under the same storage conditions, stem and leaf vegetables produce the most nitrites, followed by gourds, with root and stem vegetables and cauliflower-type vegetables in the middle. Therefore, when storing vegetables at home, you should eat stem and leaf vegetables first, such as spinach and cabbage.
8. Overnight Soup
People in the south, especially the Cantonese who are famous for their love of soups, enjoy drinking soup. It is perfectly acceptable to put leftover soup in the refrigerator and reboil it the next day. In fact, the carefully made soup from the previous day can be used to cook fantastic noodles. However, you should pay attention to the storage method for overnight soup. First, when the soup is freshly made, use a clean, uncontaminated ladle to serve it out, and then add seasonings. For any leftover soup, it should be stored in a refrigerator in a clay pot, glass, or ceramic container. It is particularly important not to use aluminum or stainless steel pots for storage, as this can easily cause chemical reactions that are not good for your health.