LABELS THAT NOTIFY FRESHNESS OF PRODUCTS

[Anchor Lead]

Fish and meat are prone to rotting when exposed to temperatures higher than 10 degrees for a prolonged time. Korean researchers have developed a sticker that notifies for how long a fresh product has been exposed to room temperature and whether or not it's safe to eat.

[Pkg]

A piece of frozen cake is left at room temperature. The exclamation mark printed on the sticker becomes clearer as the cake thaws. This means the cake is no longer safe to eat after prolonged exposure to room temperature. Made of a nano fiber one-billionth of a meter in thickness, the sticker is designed to alert consumers of food safety. The nano fiber is opaque in low temperatures, but when exposed to room temperature for a certain amount of time, its structure is destroyed, turning it transluscent.

[Soundbite] CHOI SE-JIN(KOREA RESEARCH INSTITUTE OF CHEMICAL TECHNOLOGY) : "The rough surface of the fiber turns flat with time according to the temperature. When it's completely flat, it becomes transluscent."

Once the film becomes transluscent, it can't become opaque again even when the temperature is lowered. This means the sticker is tamper-evident. Moreover, its properties are retained even when bent or cut.

[Soundbite] OH DONG-YUP(KOREA RESEARCH INSTITUTE OF CHEMICAL TECHNOLOGY) : "This sticker can be used in a wide range of food products, because the time of the nano fiber becoming transparent can be extended from 30 minutes to 24 hours by adjusting its thickness."

The sticker, which can measure the time of a product's exposure to room temperature through changes in its density, helps consumers easily find out if a product is safe to eat. It costs only 10 won to produce one sticker. The invention is expected to be widely used not only in the food distribution sector but in the pharmaceutical industry as well.