doiSerbia

Study of vacuum and freeze drying of bee honey

Nedić Nebojša M. (University of Belgrade, Faculty of Agriculture, Zemun, Belgrade, Serbia)
Gojak Milan D. (University of Belgrade, Faculty of Mechanical Engineering, Belgrade, Serbia)
Zlatanović Ivan J. (University of Belgrade, Faculty of Agriculture, Zemun, Belgrade, Serbia)
Rudonja Nedžad R. (University of Belgrade, Faculty of Mechanical Engineering, Belgrade, Serbia), nrudonja@mas.bg.ac.rs
Lazarević Kristina B. (Food Testing Center, Belgrade, Serbia)
Dražić Milan S. (University of Belgrade, Faculty of Agriculture, Zemun, Belgrade, Serbia)
Gligorević Kosta B. (University of Belgrade, Faculty of Agriculture, Zemun, Belgrade, Serbia)
Pajić Miloš B. (University of Belgrade, Faculty of Agriculture, Zemun, Belgrade, Serbia)

The aim of this research is to study the drying kinetics of vacuum-dried and freeze-dried bee honey produced from two different varieties: Sunflower honey (Helianthus Annuus L.) and Acacia honey (Robinia pseudo acacia L.). Vacuum drying treatments were carried out with the honey samples’ initial temperatures of +25°C, –20°C, and –40°C. Water content, total soluble solids, as well as the water activity of fresh and dried honey samples were determined. Freeze-drying of bee honey with initial sample temperature of –40°C has resulted in shorter drying time (7-9 hours), moisture content (10%-12%), water activity (0.405-0.427 aW) and effective moisture diffusivity coefficient (8.26·10–7-9.51·10-7 m2/s). The high-performance liquid chromatography method was used when analyzing the impact that drying pre-treatments had on honey quality. The application of pre-treatments has led to an increase in hydroxy-methyl-furfural by 39-71%, and a decrease in diastase activity by 17-36%, all compared to fresh honey samples. The solutions of Verma model proved to be the best fit with the experimental results.

Keywords: vacuum drying, freeze drying, bee honey, drying kinetics, quality parameters

Projects of the Serbian Ministry of Education, Science and Technological Development, Grant no. 451-03-68/2020-14/200116 and Grant no. 451-03-68/2020-14/200105