The Fraunhofer Research Institution for Modular Solid State Technologies EMFT in Munich has developed a new sensor film that changes color to warn of spoiled food. When meat or fish are packaged, it is not possible to detect whether they are fresh or spoilt.
The sensor film can be integrated into the inner side of food packaging. When foods such as meat and fish decay, they produce amines. The indicator dye present in the sensor film responds to the biogenic amines by changing its color from yellow to blue, warning that the food is inedible.
In packaging, the food does not come into direct contact with the sensor film as a barrier layer between the food and the film allows only gaseous amines and prevents the indicator chemicals from passing through. Using electronic sensors to indicate spoilt food is expensive, while the sensor film offers a cheaper option.
The German Federal Ministry of Education and Research sponsored the project for development of the sensor film
Source: http://www.emft.fraunhofer.de/