Electrical impedance spectroscopy applied to quality control in the food industry

Electrical impedance spectroscopy (EIS) is a technique used to analyze the electrical properties of diverse materials, including the biological, inducing, and measuring alternating electrical signals at different frequencies. Impedance measurements are employed to establish ripeness in fruits, identify adulterations in meat and dairy products, determine physicochemical properties in all types of food matrices, and even to quantify microorganisms present in food and on work surfaces. This technique is safe, non-invasive, fast, portable, inexpensive and easy to use, which makes it a method with great potential to be used in the food industry to monitor and control quality processes. This systematic review compiles scientific information published between the years 2012 and 2018 that describes the use of EIS applied to food quality control. Searches were made through the databases ScienceDirect and Springer as well as using the search engine Google Scholar, through the strategy: Spectroscopy electrical impedance AND Foods. After using a series of filters and a manual search, 52 articles and four theses related to the topic were found. The systematic review showed that most of the studies focus on the quality assessment of meat and fishery products, as well as on the characterization of the changes generated during the thermal processes and fruit ripening.