These days, the demand for rushing and buying before the tax increase is increasing. Daily necessities are good, but when it comes to hoarding groceries, I'm worried about the "best-by date." I bought it cheaply, but the expiration date expired while I kept it in the refrigerator, and when I had to throw it away, I had no children.

However, if you have this, you may not have to worry about it anymore.


Researchers at Beijing University in China have developed "Smart Tags " that can distinguish freshness by "color change". The US media CBS News reports .

The smart tag is a small gel-like sticker that is as small as a little fingernail. But don't be afraid. Simply stick this tag on the package and it will tell you if the food is rotten without opening the seal.


According to the media, if the smart tag is red or dark orange, the food is fresh. But over time, the tag color changes to orange, yellow, and green. When it turns completely green, the food is "100% rotten."

For example, suppose you have milk with a best-by date of 14 days. If the color of the attached smart tag changes from red to orange, it means that the milk has a best-by date of about 7 days.


The smart tag, which distinguishes the freshness of food, drinks, and even drugs, was announced on March 17 at the American Chemical Society's National Meeting in Dallas in Texas, USA, and was already in the spotlight. Seems to be there.

Certainly, with this, you can see the freshness at a glance, so it seems that you can use up the food you bought in bulk without wasting it. However, it's a mess to buy unnecessary things and use them as fertilizer in the refrigerator just because they have this.

In the end, buying only what you need, rather than hoarding groceries indiscriminately, may be the best “cheap”.

* All images and videos are sourced from the official Youtube channel of the American Chemical Society.