Dielectric properties of honey: the potential usability for quality assessment

The Importance of Testing the Quality and Authenticity of Food Products: The Example of Honey

The aim of this study was to review methods of honey testing in the assessment of its quality and authenticity. The quality of honey, like other food products, is multidimensional. This quality can be assessed not only on the basis of the characteristics evaluated by the consumer during purchase and consumption, but also on the basis of various physicochemical parameters. A number of research methods are used to verify the quality of honeys and to confirm their authenticity. Obligatory methods of assessing the quality of honey are usually described in legal acts. On the other hand, other, non-normative methods of honey quality assessment are used worldwide; they can be used to determine not only the elementary chemical composition of individual types of honey, but also the biological activity of honey and its components. However, so far, there has been no systematization of these methods together with a discussion of problems encountered when determining the authenticity of honeys. Therefore, the aim of our study was to collect information on the methods of assessing the quality and authenticity of honeys, and to identify the problems that occur during this assessment. As a result, a tabular summary of various research methods was created.

Dielectric properties of honey adulterated by sugar syrup

Dielectric properties of pure honey adulterated by varying amount of sugar syrup have been measured over 20 Hz to 2 MHz frequency range, at room temperature. The samples were prepared by mixing different proportions of sugar syrup in pure honey. It has been observed that, dielectric constant (ε′) and dielectric loss (ε″) of the mixture increases as percentage of sugar-syrup in honey increases. ε′ of the mixture decreases rapidly with the increase in frequency and achieves static value at higher frequency. ε″ decreases linearly with increase in frequency. The relaxation time corresponding to tanδ peak varies nonlinearly with increase in concentration of sugar syrup in the honey. The dielectric loss at 2 MHz, and the relaxation frequency of the mixture increases linearly with increase in concentration of sugar syrup in honey, which can be used to estimate the amount of adulteration of honey by sugar syrup.