"Mom, this stuff is about to expire, why did you buy so much?" "Oh, you know what, this is a good deal, it is not yet expired, you and I will eat before the expiration of the old man."

"The dishes have been left overnight. If you eat too much, it's not good for your health. "" When leftovers are hot and you eat the same, you kids are used to a good life."

Are these scenes often played out at home? Today, dietitians are most concerned about "food" and "overnight dishes"; to talk about.

     I. Is the food safe?

Recently, because they like to "pick up phase", temporary food has become popular, and many big grandpa and aunt have become major buyers of temporary food. So is the food in season safe?

Imminent food refers to the food that is about to reach the shelf life, but is still within the shelf life, and belongs to the range of safe food. The food within the shelf life is only the manufacturer's commitment to the best taste and safety for consumers. The shelf life is not equivalent to safety. After the shelf life, it does not mean that it becomes unsafe, but the quality is poor. Temporary food is not expired food, the price of temporary food is discounted, the quality is not discounted, you can rest assured to eat.

Generally speaking, the longer the shelf life of food, the longer the critical period of food shelf life:

Shelf life ≥1 year, critical period is 45 days before expiration, such as canned food, biscuits, etc.

Shelf life from 6 months to 1 year, critical period is 20 days before expiration;

Shelf life from March to June, the critical period is 15 days before expiration;

Shelf life from January to March, the critical period is 10 days before expiration;

The shelf life is 0.5 to 1 months, the critical period is 5 days before the expiration;

Shelf life < 0.5 months, the critical period is 1~4 days before expiration;

There is no problem with temporary food purchased through regular merchants. But also note:

1.For the food in the near term, if it is not eaten at home in time, it is a "waste", so even if the food in the near term is cheap, it should be purchased within its own ability;

2.At the same time, when storing the food in the near future, pay attention to the preservation according to its preservation requirements.

Two, can't eat overnight vegetables?

First of all, to correct a misunderstanding - not put overnight food is considered as overnight food, any place time of more than 8-10 hours can be considered as overnight food, so the morning meal may also be considered as overnight food in the evening. Why is it bad to eat overnight food?

1, overnight vegetables are easy to produce nitrite, but nitrite is contained in food, vegetables, fish, eggs and meat in daily life. In fact, nitrite is not carcinogenic, and it reacts with protein decomposition products to produce "nitrosamines" under the action of stomach acid. Usually, the vegetables we eat contain high levels of nitrate, especially root vegetables such as celery and leek and green leafy vegetables, which can be gradually converted into nitrite during storage, and the nitrite generated will not be reduced with the heating of food.

Research shows that the nitrite content of overnight vegetables stored at room temperature after cooking is higher than that stored in cold storage after cooking, the nitrite content of uncooked vegetables stored in cold storage is lower than that stored in cold storage after cooking, and the nitrite content of uncooked meat stored in cold storage is slightly higher than that stored in cold storage after cooking.

The World Health Organization stipulates that the daily allowable intake of nitrite is 0 ~ 0.2 mg/kg body weight, although it will not eat a toxic dose, but long-term eating overnight vegetables will also cause damage to the body.

2, the loss of some nutrients in food. Vegetables are rich in vitamin C, in cooking, because vitamin C is not resistant to high temperature, has lost part, when the food is heated again, there is not much VC will become less, the same vegetables contain carotene, lutein and so on.

3, when food is stored in the refrigerator, the refrigerator can not play the role of sterilization. At the same time, it should be noted that the refrigerator is not a safety box, and the food is also at risk of deterioration, and it is not recommended that the overnight rice be placed for too long. Overnight meals need to be completely heated before eating, especially for the elderly, children and other people with weak gastrointestinal tract, but also pay attention to food safety and hygiene.

Prepare ingredients as needed, make food, and strive to achieve meals and discs without waste.

reference

[1] Ruan Guangfeng. What is the expiration date of food? How safe is the food at the moment? [N]. China Market Supervision Journal. 2021-6-24 (8)

[2] Wang W J. Analysis of changes of nitrite content in overnight vegetables before and after cooking [J]. Food Safety Guide,2020(36):119-122. (in Chinese)

 

Nutrition and Food Safety Branch