A Simple Imaging Strategy for In-Line food Inspection via Microwave Imaging

Microwave imaging can represent an alternative for in-line inspection of food products, to reveal the presence of possible foreign bodies that may have contaminated the product during the transformation and/or packaging stages. To this end, a microwave system specifically meant for such purpose has been recently proposed. With respect to this device, a novel imaging strategy is presented, which allows one to build the image of the target without the need of a contaminant-free item used as reference sample. The idea is still to perform a differential imaging taking advantage of possible symmetries of the object under test with respect to the imaging system. These symmetries only occurred in a contaminant-free item, while are broken by the presence of an inclusion, thus revealing their presence. A quite common case is that of food packaged in circular plastic/glass jars. A simple numerical example is provided showing the capabilities of the approach.