Dielectric properties of honey: the potential usability for quality assessment

Honey, as a valuable product of high price, is subject to illegal adulteration by adding water or inexpensive sweeteners as well as overheating. Therefore, cheap, quick, and reliable methods of honey quality assessment are of interest to the food industry and consumers alike. In this study, two dielectric honey parameters: relative permittivity and dielectric loss coefficient measured at frequencies below 1 MHz and at temperatures from 20 to 40 °C were considered as potential indicators of honey quality. For the data analysis, chemometric methods (artificial neural networks and two methods of extracting the contribution of independent variables) were employed. No significant differences in results of the relative contribution of input variables were found depending on frequency. Results lead to the conclusion that relative permittivity, which is significantly affected by pH, can be potentially useful for honey microbial contamination detection and dielectric loss coefficient, influenced mostly by HMF content, can be considered as an indicator of honey freshness.