Effect of Heat Treatment on Chemical and Sensory Properties of Honeys

Honey has been widely used since the ancient times. Due to its high nutritional value and its high price honey has become a target of adulteration. Several methods are applied for committing frauds. For some beekeepers and distributors it is a common practice to heat honey for elimination of crystallization, which is generally not desired by consumers. Nevertheless, during heat treatment the chemical composition changes, leading to a decrease in the amount of some components like vitamins, antioxidant components and enzymes, while some unwanted compounds like hydroxymethyl-furfural (HMF) are formed. HMF is also produced during long time storage at room temperature, but heating promotes this process. In our research the effect of heat treatment was studied on different chemical, physical and sensory properties of honeys. Linden, acacia, multiflora and sunflower honeys were examined. Three temperature levels - 40 °C, 50 °C, 60 °C- and three time periods – 30, 60, 120 minutes - were applied for the heat treatment. For tracking of the changes colour measurement, near infrared spectroscopy and electronic tongue methods were used. Evaluation of data was performed by uni- and multivariate statistical methods. Samples treated even at 40 °C showed significant differences compared to the control, mainly in ET and NIR results. Furthermore, the effect of the different time periods was also found significant. Results confirmed even heat treatment at 40 °C is detectable with the acquired rapid methods. higher heat treatment cause obvious sensory changes but the applied quick methods are able to trace the effect of minimal heat treatment on the quality of honey.