Jan 4 2019
Ten million metric tons of food is being dumped in the garbage annually in Germany in spite of it still being edible, according to a study by the environmental organization WWF Germany. Soon a mobile food scanner will enable consumers and supermarket operators to test whether food items have gone stale. The pocket-size device uses infrared measurements to establish the ripeness and shelf life of produce and show the results via an app. Fraunhofer scientists created the system, which exists in demonstrator form, along with partners in a project commissioned by the Bavarian Ministry of Food, Agriculture, and Forestry.
Many food items wind up in the garbage even though they are still edible. A compact food scanner will help avoid unnecessary food waste in the future. (© Fraunhofer IOSB)
Are those vegetables still fresh? Is this yogurt still edible? When there is doubt, people are inclined to throw food into the garbage. Many products are disposed of just because they do not look appealing or have superficial marks, or because they are past their best-before date. In Bavaria alone, 1.3 million tons of food end up in the garbage needlessly each year.
Through the “We Rescue Food” alliance, the Bavarian Ministry of Food, Agriculture, and Forestry aims to fight waste by means of 17 initiatives. One of the projects concerns a food scanner built to help decrease waste at the end of the value chain—in stores and in consumers’ homes. In the future, the low-cost pocket-size device will establish the real freshness of food, whether packaged or unpackaged. Scientists at the Fraunhofer Institute for Optronics, System Technologies and Image Exploitation IOSB, the Fraunhofer Institute for Process Engineering and Packaging IVV, the Deggendorf Institute of Technology, and the Weihenstephan-Triesdorf University of Applied Sciences are designing the compact food scanner, which has been constructed as a demonstrator with data for two foodstuffs and also permits the shelf life of products to be assessed.
Using infrared light to determine the authenticity of food
The center of the mobile scanner is a near-infrared (NIR) sensor that measures the ripeness of the food and recognizes the amount and composition of its contents.
Infrared light is beamed with high precision at the product to be investigated and then the scanner measures the spectrum of the reflected light. The absorbed wavelengths allow us to make inferences about the chemical composition of the food.
Dr. Robin Gruna, Project Manager and Scientist, Fraunhofer IOSB
“In the laboratory, we’ve long been able to quantify individual components using near-infrared spectroscopy. What’s new is that this can now be done with small, low-cost sensors,” adds Julius Krause, a member of Gruna’s team. “Foodstuffs are often counterfeited—for example, salmon trout is sold as salmon. Once suitably trained, our device can determine the authenticity of a product. It can also identify whether products such as olive oil have been adulterated,” says the physicist. But there are restrictions to the system, too: It can only assess the product quality of homogeneous foods. Right now, it struggles to scrutinize heterogeneous products containing various ingredients such as pizza. To this end, the researchers are exploring high-spatial-resolution technologies such as hyperspectral imaging and fusion-based methods using spectral sensors and color images.
To be able to establish the quality of food based on the sensor data and the measured infrared spectra and calculate the shelf-life predictions, the study teams are preparing intelligent algorithms that hunt for telling patterns and regularities in the data.
Through machine learning, we can increase the recognition potential. In our tests, we studied tomatoes and ground beef. For instance, we used statistical techniques to correlate the measured NIR spectra of ground beef with the rate of microbial spoilage and derived the remaining shelf life of the meat from the results.
Dr. Robin Gruna, Project Manager and Scientist, Fraunhofer IOSB
Wide-ranging storage tests, whereby the research teams measured microbiological quality and other chemical parameters under different storage conditions, revealed a good correlation between the computed and real total germ counts.
App displays shelf life of food
The scanner transmits the measured data via Bluetooth to a database for analysis. This database is a specially developed cloud solution in which the evaluation approaches are stored. Then, the test results are conveyed to an app that displays them to the user and shows how long the food item will stay fresh under various storage conditions, or specifies that its shelf life has already passed on. Furthermore, the consumer is given instructions on different ways of using food that is past its best-before date.
A test phase is scheduled to begin in supermarkets at the start of 2019, which will study how consumers react to the device. More generally, it is anticipated that the versatile technology will be used across the value chain, from raw material to final products. Its ability to detect variations in quality at an early stage facilitates alternative uses and helps decrease waste, but the scanner is more than merely an instrument for analyzing food items. It might be better defined as a general-use, economical scanning technology that can be easily adapted. For instance, the system could be used to sort, separate, and classify textiles, wood, plastics, and minerals. “The range of potential applications is very wide; the device just needs to be trained accordingly,” says Gruna.