“Overnight vegetables, will be poisoned, do not eat again…”
“I heard that some people eat overnight vegetables for a long time, and later found out stomach cancer ….”
“Overnight vegetables contain nitrite, is a “poisonous dish” ……”
In recent years, the topic of “whether overnight vegetables are healthy” has been a constant source of controversy, some say that overnight vegetables are harmful to the body, some say that overnight vegetables are poisonous, and some say that overnight vegetables contain carcinogens, and for a time people have a soft spot for overnight vegetables.
Overnight vegetables as Chinese family life is difficult to avoid the diet products, every household has had the experience of eating overnight vegetables, despite the endless harmful claims, but some people who eat overnight vegetables all year round did not feel sick, it seems that rumors and experience does not match.
Is there any harm in overnight food, “poisoning and carcinogenic” argument from where it comes?
First, how long after the meal, belong to the overnight food?
In the traditional impression and people’s perception of life, overnight food, refers to the meal after eating the rest of the meal, because it is a pity to throw away the next day to continue to eat, after a night became the so-called overnight food, but the scientific community on the “overnight food” explanation is different from this.
From a scientific point of view, overnight vegetables should be judged by bacterial growth, foreign body invasion, harmful substances, etc., and this process and time, storage channels, storage temperature, the sealing of the storage, and even environmental humidity, etc., have a lot to do with the general environment, but in general, or the influence of time is greater.
Strictly speaking, the time standard of overnight vegetables is 6-8 hours, as long as the time standard, regardless of whether there is consumption, belongs to the overnight vegetables.
Second, overnight food is not only toxic but also carcinogenic?
Overnight food after a period of time, may be subject to the invasion of foreign substances, bacterial growth, as well as new substances in the food, and the normal consumption of food, overnight food on health is an indisputable fact, but whether there is poisoning and cancer so serious?
Overnight food is poisonous and carcinogenic, mainly from a substance – “nitrite”. Medical research has found that nitrite is acutely toxic to the human body when 300-500 mg is consumed at a time, and nitrite can also be combined with amines produced by the decomposition of proteins in the body in the stomach acid environment to form nitrosamines.
Nitrosamines are a class 1 carcinogen identified by the World Health Organization.
So it seems that overnight vegetables can really be toxic and carcinogenic, however, scientific research has found that when plants grow they absorb nitrogen from nutrients and form amino acids, a process that produces nitrates.
Plants contain nitrate reductase enzymes that reduce nitrate to nitrite (some bacteria have the same effect), so all plants that are naturally separated from the rootstock have a certain amount of nitrite.
In the medical world, “toxicity” and “dose” are linked. Ningbo Food Inspection and Testing Institute has done a study on overnight vegetables.
The study was conducted by selecting 30 home-cooked dishes from four types of dishes, such as meat, vegetarian, cold dishes, meat and vegetarian dishes, which were placed at 4 degrees Celsius (refrigerator) and 25 degrees Celsius (room temperature), and the nitrite content and microbial growth in 0h, 6h, 12h and 24h.
Comparison of test data found that: at 4 degrees Celsius, the dishes after 6h, 24h nitrite content rose from 3 mg per kg to 7 mg, up to 10 mg, basically little change, a small number of microbial growth, but also does not affect the consumption.
In the room temperature of 25 degrees Celsius, food in 12h meat and vegetables nitrite content does not change much, leafy vegetables nitrite content increased sharply, a few reached 20 mg per kg, 24h after even reached 100 mg, in addition to microorganisms in 12h after the exponential growth.
From the above data, overnight vegetables if stored in the refrigerator, 24h can also be eaten, but in the room temperature environment, 6-12h has entered the risk period, more than 24 hours on the human body harmful dramatically increased, so life must pay attention to the preservation of overnight vegetables!
Third, overnight vegetables can still be eaten or not?
Although the harm of overnight food is not so great, but the potential risk is not eliminated, so daily life should still reduce the intake of overnight food, and if it is unavoidable to produce leftovers, please pay attention to the safe preservation. These three types of food should be given extra attention!
Fish, meat, soy products: fish, meat, meat products, although containing very little nitrite, but also not easy to produce nitrite, but their common feature is rich in high-quality protein, is a natural “bacteria Petri dish”, so if put too long is easy to breed bacteria.
Rice, pasta and other starch-rich foods: starchy foods are susceptible to Bacillus cereus invasion, it is easy to cause infection, resulting in diarrhea, vomiting, abdominal pain and other symptoms, so this type of food to pay attention to the amount, it is best not left.
Leafy vegetables: natural leafy vegetables themselves contain a certain amount of nitrite, as mentioned above, and research data from the Ningbo Quality Inspection Institute also shows that at room temperature, the nitrite content of leafy vegetables exceeds 20 mg per kg within 12 hours, and may reach 100 mg after 24 hours. This shows that people should still be vigilant about leafy vegetables.
Fourth, overnight vegetables should be handled in this way
As mentioned above, overnight vegetables in different temperatures, different environments, and even different types of ingredients and other factors, the harmful effects are different, the most critical is the preservation of the need for certain skills. Life overnight dishes must be handled in this way!
- rather leftover meat than leftover vegetables
The general table is divided into meat and leafy vegetables, and leafy vegetables are more likely to produce nitrite, but also easy to spoil, so the diet to vegetable priority, to do “rather leftover meat not leftover vegetables”, of course, it is best to “meat and vegetables are not left”.
- Divided in advance, reasonable storage
When dealing with leftovers, we should pay attention to different food, on the one hand, different food taste different, place the string taste, on the other hand, different food characteristics are different, some easy to produce nitrite, some easy to breed bacteria, separate is conducive to preservation. In addition, the food will be sealed with plastic wrap can extend the shelf life, for some commonly used food, divided into packages is also conducive to access.
- Thorough heating
Overnight vegetables must be heated before eating, heating temperature up to 100 degrees Celsius, time about 3 minutes, the best sterilization effect. If there are too many overnight vegetables, you can separate them and heat them in small amounts to avoid repeated heating.
- Regularly clean the refrigerator
Although the refrigerator is conducive to food storage, but some bacteria prefer the low-temperature refrigerator environment, a long time in a large amount of food storage, but also inevitably breeding bacteria, so generally every 3 months to clean up, keep the refrigerator clean, sterile environment.
Although it is true that overnight food may be detrimental to human health, in the long run, people still want to reduce consumption, but it is not as harmful as the rumors of “Yusheng arsenic” so big.
So we don’t have to choke on it and panic too much. The discussion on the dose and toxicity of overnight vegetables also hopes to draw attention to the fact that people can not blindly spread rumors.
