Chinese New Year's Eve dinner is the highlight of the Spring Festival, but leftovers are also head-catching: some Chinese New Year's Eve meals are eaten from the first day of the new year to the fourth day of the new year; Some Chinese New Year's Eve meals are managed for seven days, which can be called "seven days left"...
Some people feel that they are wasted and keep it and worry that it will not be good for their health. So can you eat the Spring Festival "leftover feast"? What foods are not suitable for reheating? How do you store leftovers?
Source: Kale** Photography Jia Qiong.
Can eating leftovers cause cancer?
I often hear people say that there is nitrite in overnight dishes, which can cause cancer, is this true?
In fact, nitrite itself is not carcinogenic, but in the gastric acid environment, it can react with amines, the decomposition products of proteins in the stomach, to form teratogenic and carcinogenic nitrosamines, which belong to "a class of carcinogens".
Plant foods themselves contain nitrates and nitrites, and the nitrate content of green leafy vegetables is relatively high, and if the vegetables are stored for too long, the nitrite will gradually rise, so for green leafy vegetables, buy them in small quantities and try to eat fresh vegetables.
The experiment found that after 12 hours of room temperature of leafy vegetables, the nitrite content of leafy vegetables increased significantly, and some of them exceeded the upper limit of 20mg kg of nitrite (sodium nitrite) in pickled vegetables stipulated by the state, and even partially reached more than 100mg kg after 24 hours. After 24 hours of refrigeration, the nitrite content of all dishes was still within the safe value. However, most of the vitamins in vegetables will lose their activity after repeated heating, and their nutritional value will be greatly reduced.
Fish, meat, and soy products themselves have very low nitrite content, and some processed meat cooked foods will use a small amount of nitrite as a food additive to develop color and inhibit bacteria. Therefore, home-cooked meat dishes generally do not have the risk of nitrite elevation overnight.
Starchy foods such as rice and pasta can cause mold even if they are placed in the refrigerator, so leave them in the refrigerator for a maximum of one day, and don't eat leftover rice for more than two days.
Therefore, if the overnight dish is stored properly, it is actually edible, and it is alarmist to simply and rudely say that the overnight dish causes cancer.
What to do with leftovers?
Since the overnight dish is properly preserved and edible, how do you properly store the leftovers?
Leafy greens.
After repeated heating, the vitamin loss is severe, and nitrite is easy to form after overnight.
Handling suggestions: Try to finish the meal, and refrigerate as soon as possible if you can't finish it, and store it for more than 24 hours.
Root vegetables.
After repeated heating, the loss of vitamins is obvious, the nitrate content is lower than that of green leaves, and the taste is acceptable after overnight.
Handling suggestion: If you can't finish eating, divide and refrigerate as soon as possible, and you can store it for 1-2 days.
Meat, eggs.
Cooking again has less nutritional impact, but it is rich in protein and conducive to bacterial reproduction.
Handling suggestions: It can be stored properly, it needs to be refrigerated as soon as possible, and it needs to be frozen for more than 24 hours. Cooked food should be heated thoroughly before being eaten again.
Seafood and other aquatic products.
Unsaturated fatty acids are easily damaged after repeated heating, and protein degradants are easy to be produced after overnight, which damages liver and kidney function.
Handling suggestions: Try to finish the meal, and freeze the food as soon as possible.
Soybean.
Protein is not easily lost after reheating, but cooked soy products are prone to spoilage.
Handling suggestion: Try to eat it as soon as possible, and refrigerate it as soon as possible after buying it.
Mushrooms.
After repeated heating, the nutrient loss is not large, and the taste is acceptable after overnight.
Handling suggestion: If you can't finish eating, divide and refrigerate as soon as possible, and you can store it for 1-2 days.
Soups. Leftover soup stored in aluminum pots and iron pots for a long time will generate harmful substances.
Handling suggestion: Salt and other seasonings can be put less, and refrigerated in a clay pot or crisper box.
Cold dishes. After overnight, more harmful substances are generated, and it is not suitable for heat treatment.
Handling suggestion: Regardless of meat and vegetarian, try to eat it as soon as possible.
It is best not to reheat these foods
Specifically, what other foods are not suitable for reheating? What is the reason for this?
Spinach:The oxalic acid content is high, and it needs to be blanched before eating, plus spinach contains a lot of nitrate, which will be converted into nitrite when heated twice, which is harmful to the human body.
Milk:Repeated heating of milk denatures the proteins in the milk, leading to nutrient deficiencies. At the same time, bacteria multiply rapidly, causing milk to spoil and cause diarrhea.
Mushroom food:Mushrooms in mushrooms will produce a large amount of nitrate after high-temperature cooking, and if they are stored at low temperature in the refrigerator and heated the next day, the nitrite content will increase when they are heated the next day.
Frequent consumption of reheated mushrooms may cause symptoms such as abdominal pain and diarrhea, and in the long term, it will increase the probability of developing digestive system tumors. Therefore, it is not recommended to continue eating mushrooms after reheating them, and try to eat them all at once.
White fungus soup:Tremella contains a lot of nitrates, and if cooked tremella soup is left for too long, the nitrates will decompose and reduce to nitrite. Nitrite will make the hemoglobin in the blood lose its ability to carry oxygen, thereby disrupting the normal hematopoietic function of the human body and affecting health. Therefore, white fungus soup is best made and drunk freshly, not overnight.
Soft-boiled eggs:Soft-boiled eggs mainly refer to undercooked eggs, such eggs cannot completely kill Salmonella, if left overnight, will increase the chance of bacteria multiplying and toxin production, even if cooked a second time, there is a risk of disease.
Source: Kale** Photography Jia Qiong.
Refrigerator food preservation recommendations
Do you have to wait until it's cold before you can put leftovers in the fridge? There is also a particular focus on how to store leftovers in the refrigerator.
Refrigerate as soon as possible
The longer any food is left at room temperature, the more microorganisms will multiply and the less safe it will be. Try to keep leftovers hot or in the refrigerator when they're not hot.
The contents of the refrigerator should not be too full, the dishes should not be too large, try to use a lightweight, fast heat conduction fresh-keeping box, can speed up the cooling speed.
Store separately
Separate storage avoids bacterial cross-contamination. Store tightly closed in a clean container or wrap bowls and pans in plastic wrap.
Warm thoroughly before eating
Refrigerate frozen leftovers before eating, be sure to return to the pot at high temperature, heat the whole dish to 100, and keep boiling for more than 3 minutes.
To heat the microwave, you need to turn it over and heat it for a few more minutes. Eat as much as you want and avoid reheating.
The "leftover feast" of the Spring Festival is inevitable, but we must learn the correct way to deal with it and spend a healthy Spring Festival holiday!
Perspective News Comprehensive CCTV News, Beijing Municipal Center for Disease Control and Prevention, Hubei**, Popular Science China Report).
Editor: Liu Songling.
Proofreader: Li Xuying.
Review: Gong Zimo.