<abstract xmlns="http://www.w3.org/1999/xhtml"><p>Thermodynamic properties of selected honeys: glass transition temperature (Tg), the change in specifi c heat capacity (ΔCp), and enthalpy (ΔH) were analysed using differential scanning calorimetry (DSC) in relation to the composition i.e. water and sugar content. Glass transition temperatures (Tg) of various types of honey differed significantly (p&lt;0.05) and ranged from -49.7°C (polyfloral) to -34.8°C (sunflower). There was a strong correlation between the Tg values and the moisture content in honey (r = -0.94). The degree of crystallisation of the honey also influenced the Tg values. It has been shown that the presence or absence of sugar crystals influenced the glass transition temperature. For the decrystallised honeys, the Tg values were 6 to 11°C lower than for the crystallised honeys. The more crystallised a honey was, the greater the temperature difference was between the decrystallised and crystallized honey. In conclusion, to obtain reliable DSC results, it is crucial to measure the glass transition after the complete liquefaction of honey.</p></abstract>

Thermodynamic properties of selected honeys: glass transition temperature (Tg), the change in specifi c heat capacity (ΔCp), and enthalpy (ΔH) were analysed using differential scanning calorimetry (DSC) in relation to the composition i.e. water and sugar content. Glass transition temperatures (Tg) of various types of honey differed significantly (p<0.05) and ranged from -49.7°C (polyfloral) to -34.8°C (sunflower). There was a strong correlation between the Tg values and the moisture content in honey (r = -0.94). The degree of crystallisation of the honey also influenced the Tg values. It has been shown that the presence or absence of sugar crystals influenced the glass transition temperature. For the decrystallised honeys, the Tg values were 6 to 11°C lower than for the crystallised honeys. The more crystallised a honey was, the greater the temperature difference was between the decrystallised and crystallized honey. In conclusion, to obtain reliable DSC results, it is crucial to measure the glass transition after the complete liquefaction of honey.

Differential Scanning Calorimetry for Determining the Thermodynamic Properties of Selected Honeys

University of Life Sciences, Wojska Polskiego 31, 60-624 Poznan, Poland

Bialystok University of Technology, Wiejska 45A, 15-351 Białystok, Poland

Journal of Apicultural Science

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

Thermodynamic properties of selected honeys: glass transition temperature (Tg), the change in specifi c heat capacity (ΔCp), and enthalpy (ΔH) were analysed...

Differential Scanning Calorimetry for Determining the Thermodynamic Properties of Selected Honeys

Pubblicato online: 29 mag 2015

Pagine: 109 - 118

Ricevuto: 07 feb 2015

Accettato: 11 mag 2015

DOI: https://doi.org/10.1515/jas-2015-0012

© by Sławomir Bakier

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.