Sensor that changes color when it detects spoiled food

Scientists have invented a sensor film that changes color when food is degraded.

This sensor will be placed on packages of meat and will serve to quality control the products. The indicator will react to the amines in the package and thus, following certain chemical reactions, it will change color from yellow to blue. The amines are molecules produced when food enters the state of decomposition; they are also responsible for the odor of meat products.

If amines are released into the air inside a package of meat, they will come into contact with the sensor film, which will change color.

“Once a certain concentration range is reached, the color change is clearly visible and assumes the task of warning the consumer,” explains Dr. Anna Hezinger, a scientist at EMFT. This device will not only help in finding expired food in stores, but also to warn people who are sensitive to certain amines in meat.

“Unlike the expiration date, the information on the sensor film is not based on an estimate but on an actual control of the food itself,” Hezinger explains.

The system is not expensive, leading to widespread use of this indicator. Other solutions, such as electronic sensors, would result in a significant increase in the price of packaged meat. Also, all things that come into direct contact with the meat will have to meet high quality standards.

“Food safety is ensured by a barrier layer between the sensor film and the product itself. This barrier is only permeable to gaseous amines. The indicator chemicals cannot pass through,” says Dr. Hezinger.

Scientists are working on a measurement device with a built-in sensor. Employees working in the meat industry and product packaging will be able to directly use this device to test the freshness of meat. The device will have to be able to analyze the resulting color after testing and to ensure more accurate results than it is possible with the human eye. It will also provide detection of different shades of color.

Currently, Dr. Anna Heizner and her team are looking for partners to further develop this project and to produce the sensor and measuring device.