The use of dielectric honey features for overheating diagnostics

Abstract

During processing operations, honey can be exposed to excessive heat. That adversely affects the quality of product (its biological activity). The aim of this work was to test the possibilities of the use of dielectric properties (relative permittivity and dielectric loss coefficient) for honey overheating detection. Nine honey types obtained directly from beekeepers were investigated. Honey was heated at the temperatures 60, 70, 80, and 90 °C for 24 hours and then cooled down to 25–26 °C. At that temperature, dielectric properties of biological material under study were determined. In the frequency range 400 Hz to 4 kHz, the significant influence of thermal treatment temperature on both dielectric parameters was observed. Both dielectric parameters decrease as the heating temperature increases. The statistical analysis suggested that dielectric parameters can be used for distinguishing honey overheated from not overheated. Therefore, they can be potentially useful for honey quality assessment according to its overheating, e.g. in co-packing process. The proper frequency range for these parameters measurement is 1–4 kHz.