Electrical impedance measurements for detecting artificial chemical additives in liquid food products

Analyzing the content of artificial chemical additives in food products is important due to their twofold role in food processing and consumption, i.e., their positive impact on the shelf life or sensory properties of food products and possible negative effect on human health. The objective of the research was to evaluate the usefulness of the impedance spectroscopy technique in food quality control by testing its potential for determining the additives content in liquid food products. The impedance readings of one- and two-component solutions of twelve common food additives and six natural juices, both pure and with additions of selected chemical additives, were collected within the frequency range from 20 Hz to 2 MHz. The resulting spectra were interpreted with the use of the equivalent electrical circuit approach. An optimal circuit which allowed to describe electrical properties of the investigated samples was selected. It was characterized by four physical parameters, two of which may be used for the differentiation among food additives. The impedance spectroscopy technique has a potential to become an effective method for food quality and safety control in the context of the artificial additives content, because it allows to describe the content in a relatively simple manner when the compounds of interest are present in small quantities in chemically complex materials such as foods.