{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,3,14]],"date-time":"2026-03-14T05:15:22Z","timestamp":1773465322558,"version":"3.50.1"},"reference-count":18,"publisher":"MDPI AG","issue":"2","license":[{"start":{"date-parts":[[2023,1,10]],"date-time":"2023-01-10T00:00:00Z","timestamp":1673308800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Italian Ministry of University and Research","award":["20179FLH4A"],"award-info":[{"award-number":["20179FLH4A"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>Microwave imaging has been recently proposed as alternative technology for in-line inspection of packaged products in the food industry, thanks to its non-invasiveness and the low-cost of the equipment. In this framework, simple and effective detection\/imaging strategies, able to reveal the presence of foreign bodies that may have contaminated the product during the packaging stage, are needed to allow real-time and reliable detection, thus avoiding delays along the production line and limiting occurrence of false detections (either negative or positive). In this work, a novel detection\/imaging approach meeting these requirements is presented. The approach performs the detection\/imaging of the contaminant by exploiting the symmetries usually characterizing the food items. Such symmetries are broken by the presence of foreign bodies, thereby determining a differential signal that can be processed to reveal their presence. In so doing, the approach does not require the prior measurement of a reference, defect-free, item. With respect to the quite common case of homogeneous food packaged in circular plastic\/glass jars, numerical analyses are provided to show the effectiveness of the proposed approach.<\/jats:p>","DOI":"10.3390\/s23020779","type":"journal-article","created":{"date-parts":[[2023,1,10]],"date-time":"2023-01-10T02:27:12Z","timestamp":1673317632000},"page":"779","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":11,"title":["A Simple Differential Microwave Imaging Approach for In-Line Inspection of Food Products"],"prefix":"10.3390","volume":"23","author":[{"given":"Noemi","family":"Zeni","sequence":"first","affiliation":[{"name":"Department of Electric Engineering and Information Technologies, University of Naples Federico II, 80125 Naples, Italy"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-2498-3219","authenticated-orcid":false,"given":"Lorenzo","family":"Crocco","sequence":"additional","affiliation":[{"name":"Institute for the Electromagnetic Sensing of the Environment, National Research Council of Italy, 80124 Naples, Italy"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-7624-1113","authenticated-orcid":false,"given":"Marta","family":"Cavagnaro","sequence":"additional","affiliation":[{"name":"Department of Information Engineering, Electronics and Telecommunications, University of Rome La Sapienza, 00184 Rome, Italy"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-5536-4416","authenticated-orcid":false,"given":"Gennaro","family":"Bellizzi","sequence":"additional","affiliation":[{"name":"Department of Electric Engineering and Information Technologies, University of Naples Federico II, 80125 Naples, Italy"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2023,1,10]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"255","DOI":"10.1016\/S0021-9673(00)00356-3","article-title":"Contamination in food from packaging material","volume":"882","author":"Lau","year":"2000","journal-title":"J. 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