Ultrasound to check the condition of food without touching it

Texture is a very relevant quality property in the food industry, which is influenced by many factors, such as the product’s raw material or the manufacturing process. For example, in the case of a cookie, baking too hard can make the cookie too hard (or brittle), and baking too little can lead to textures that are too soft. On the other hand, the variation in texture can also be due to small changes in composition, humidity, or other factors.

Some researchers have developed a new non-invasive ultrasonic system for the food industry that allows the texture of products derived from cereals, such as cookies, bread, snacks and pasta, among many others, to be analyzed without touching them, and in real time. Its use would allow products to be classified or rejected if they deviate from the optimum quality standard, or to adapt manufacturing processes when it is identified that the properties of the food are not correct.

This advance is the work of experts from the Higher Council for Scientific Research (CSIC) in collaboration with the Polytechnic University of Valencia (UPV), both institutions in Spain.

The system, low cost and easy to implement in the process lines, has been jointly patented by the CSIC, the UPV and the Applied Innovation Center of Cerealto Siro Foods.

“With this system it is possible to evaluate and know the quality properties of the food instantly on the production line, without touching it at any time. It would be like doing an ultrasound of the product, but without contact with the sensor”, explains José V. García-Perez, researcher of the Analysis and Simulation of Agro-Food Processes Group of the Department of Food Technology of the UPV.

Virginia Sánchez Jiménez, researcher at the UPV, with the patented device. (Photo: UPV)

“In the production line, the products circulate at a high speed and, given the nature of the product, it is impossible to use conventional ultrasound techniques with coupling by liquids or gels. In addition, as the surface of the products is very irregular, it is difficult to achieve adequate ultrasound transmission”, explains CSIC researcher Tomás Gómez, from the Leonardo Torres Quevedo Institute of Physical Technologies (ITEFI). The technology developed by Gómez and the rest of the ITEFI team manages to overcome these problems thanks to a set of emitters and receivers of great sensitivity and bandwidth, combined with a procedure for taking measurements and signal processing that allows the texture of the material to be determined. product.

The measurement consists of generating an ultrasonic wave that travels through the air, penetrates the food, propagates inside it and, again, through the air, is collected in the receiver for analysis. The mechanical properties of the food, on which the texture depends, modify the speed and attenuation of the ultrasonic wave, from which the textural properties of interest can be inferred, and thus identify products that do not meet the quality standard. Its implementation in the production line allows to analyze 100% of the production. (Source: CSIC)