Nowadays, the concept of food safety is deeply rooted in the hearts of people. People pay more and more attention to nutrition labels and shelf life when they buy food. However, to many people's headache, there are always some foods in the family that face the embarrassment of exceeding the shelf life: throwing away the pity; not throwing away, and afraid of eating problems. The problem is not only plaguing the Chinese, according to a recent report by researchers of food law at Harvard Law School and the Natural Resources Conservation Commission, as many as 40 percent of the food in the United States is discarded each year, with a per capita waste of 390 dollars per year. The reason is that more than 90 percent of Americans decide the fate of food purely on the basis of the "shelf life" on the package.

 

In fact, many people don't understand the concept of shelf life. Fan Zhihong told Life Times reporter. The definition of shelf-life is "product under normal conditions of quality assurance period". During the shelf-life, the merchant is responsible for the quality of the product, so we recommend that you eat within the shelf-life, but shelf-life is not the only criterion to determine whether food deteriorates. During the shelf life, food may deteriorate prematurely due to changes in storage methods, environment and other factors, such as packaging after opening, shelf life will be shortened; beyond the shelf life, food is not necessarily deteriorated, can not eat, which requires their own judgment.

 

Staple food. The staple food is divided into two categories according to the moisture content, the moisture content is more steamed bread, bread, moon cakes and so on, the moisture content is less such as biscuits. Bread shelf life is generally 3 to 7 days, after the shelf life, if only dry, can be made into bread crumb to eat, if mold, sour can not eat. Steamed bread is similar to bread. If mildew has grey spots, it should be discarded. The shelf life of mooncakes varies from a few days to 90 days depending on the package. Because of the high fat content in the moon cakes, they can't be eaten once the salad flavor appears during the shelf life. Biscuits with low moisture content, if sealed packaging, shelf life is generally more than a year, as long as not leaking, damp, even if expired, as long as the taste does not change generally can eat.

 

Canned type. All cans are sealed and sealed off, so the shelf life is longer and some can reach more than two years. Be careful not to buy bulging cans when buying. If the shelf life is over, the expansion can occur, often food contaminated by bacteria, this kind of cans must be thrown away. If there is no expansion tank, open it and smell it. If you have sour and miscellaneous flavor, you can't eat it. If there is rust in the tank, it should not be eaten. In addition, after the expiration date, even if it does not taste bad, it should be heated for a while.

 

Milk and milk products. The shelf life of milk varies from 48 hours to 7 days depending on the process and packaging. Milk that has passed its shelf life should be thrown away if it presents a thick, uneven solution, or if it has a clot or floc. In the summer, even if it looks normal, but also try to boil, if boiled to produce clots, indicating that bacteria exceed the standard, can not drink. Milk powder has no moisture, long shelf life, expiration time is not long, as long as there is no color darkening, visible impurities or foreign bodies, appear stale taste, moldy taste, salad taste, etc., can also be eaten. After using boiled water to make milk powder, if white clots, milk separation, or free fat floating, it will not work. If only a little lump, it can be used for dessert or cooking, that is, continue to use through heating. Expired yogurt, if there are bubbles or whey separation, does not represent toxic and harmful, which can only show that the lactic acid bacteria inside the residual lactose acidification. If there is a taste of wine, rotten taste, mildew, etc., indicating that by other bacterial contamination, can not drink.

 

Sausages and other meat products. If it is packed in vacuum, in the dry, frozen conditions placed, the nutrition will be worse, shelf life up to three years. Sausage itself is not a healthy food. It should be eaten as soon as possible near the shelf life. Over the shelf life, if there is salad taste or gut coat sticky, indicating that microbial reproduction, certainly can not eat.

 

Drinks. Generally sealed packaging, after the shelf life if there is no apparent change in appearance, no fading, turbid, precipitation, etc., should be based on the taste, odor can not drink.

 

Edible oils. In order to save money, many people buy a big barrel of oil to eat slowly. Although the oil doesn't look discolored or flavored, the peroxide value of the oil increases gradually after exposure to oxygen. Long-term consumption of such oil may increase the level of oxidation in the body and increase the risk of cardiovascular and cerebrovascular diseases and cancer. Therefore, Fan Zhihong emphasized that the oil that opened the lid must be used up within three months, and the oil poured into the oil pot must be eaten up within one week.

 

Dry fruit. Vacuum-packed dried fruits have a shelf-life of half a year to one year, but once the package is opened, problems are very likely to occur during the shelf-life. Therefore, such food should be smelled if it smells of flavour and taste. If the taste is not brittle, indicating that water, will soon deteriorate, mold, oxidative rancidity, can not.