Sometimes the designation of the expiration date on the package does not always indicate whether the product is suitable for use or not.
Scientists from the Korea Institute of Science and Technology have created a sticker that identifies spoiled food in the store. It is applied to the packaging of those products that are sensitive to temperature (meat, fish, vegetables and fruits). The sticker, among other things, keeps track of whether the products have been defrosted and refrozen.
The sticker is made of a special film consisting of nanofibers that are superimposed on each other. If the ambient temperature has not risen, the sticker remains opaque. When the temperature drops by 10 degrees, text begins to appear on the sticker. In the event that the product is placed in the right temperature conditions, the label will not return to its original position.
Scientists explained that a sign of violation of storage conditions can appear both in half an hour and in a day.
By the way, the cost of one “smart” label was estimated at one cent.