Preventing Hamburger Disease... Development of Room Temperature Exposure History Sticker

After leaving a hamburger patty taken out of the refrigerator at room temperature for 2 hours, an image appeared on the cold chain safety sticker attached to the packaging. The nanofiber film on the front of the sticker reacted to the room temperature and became transparent, revealing the image on the regular film on the back.

[Asia Economy Reporter Junho Hwang] Domestic researchers have developed a sticker that indicates the history and duration of exposure of refrigerated and frozen foods to room temperature (above 10℃). It is expected to help prevent food poisoning or hamburger disease, which occur because spoilage cannot be detected with the naked eye. The Korea Research Institute of Chemical Technology announced on the 6th that the research team led by Dr. Dongyeop Oh, Dr. Jeyoung Park, Dr. Seongyeon Hwang, and Dr. Sejin Choi from the Biochemical Research Center developed this technology and published it in the March issue of the academic journal 'Advanced Materials'.

Sticker that Indicates Room Temperature Exposure History of Food Products

Changes in the Cold Chain Safety Sticker over time after exposure to room temperature (20℃). The images in the top row show the nanofiber film on the front side of the Cold Chain Safety Sticker becoming transparent, revealing the image of the regular film on the back side. The microscope images in the bottom row depict the nanofibers breaking down over time after exposure to room temperature. The thin, interwoven nanofiber structure clumps together, allowing light to pass through.

The 'Cold Chain Safety Sticker' developed by the research team was created by attaching a nanofiber film that becomes transparent when exposed to room temperature to a regular film.

The newly developed nanofiber film changes its internal structure depending on the temperature. At low temperatures, the fibers maintain a crossed structure and exhibit an opaque appearance that does not allow light to pass through. However, when exposed to room temperature for a certain period, the nanofiber structure collapses, allowing light to pass through. At this time, the regular film behind the nanofiber film becomes visible, enabling the determination of whether it has been exposed to room temperature.

The research team also adjusted the composition and thickness of the nanofibers to control the time it takes for the nanofiber film to become transparent at room temperature. Considering that spoilage times vary depending on the food product, they set a kind of timer for each sticker to become transparent from a minimum of 30 minutes to a maximum of 24 hours.

Applicable to Cold Distribution of Various Items

Odong Yeop Oh (left) and Sejin Choi (right), researchers at the Bio-Chemical Research Center of the Korea Research Institute of Chemical Technology, are holding groceries with a "Cold Chain Safety Sticker" attached.

Dr. Dongyeop Oh said, "Once the sticker is exposed to room temperature, it cannot be restored to its original state even if refrigerated or frozen again, and the room temperature exposure time cannot be arbitrarily slowed down," adding, "The cost is also inexpensive, at around 10 won per piece."

The research team expects that the 'Cold Chain Safety Sticker' can be widely used not only for food products but also for the cold distribution of expensive pharmaceuticals. Currently, global chemical companies use kits that indicate room temperature exposure by utilizing chemical reactions of special inks for the cold distribution of high-value pharmaceuticals. However, these kits are made of hard and thick plastic, making them difficult to attach to various products, and their manufacturing costs reach several thousand won.

Dr. Sejin Choi explained, "Existing kits used for pharmaceutical distribution carry the risk of special ink leakage if damaged," and added, "In contrast, the newly developed Cold Chain Safety Sticker poses no risk of chemical leakage even if damaged during distribution, and its function operates normally."

This content was produced with the assistance of AI translation services.