Study of vacuum and freeze drying of bee honey

• Main Authors: Nedić Nebojša M., Gojak Milan D., Zlatanović Ivan J., Rudonja Nedžad R., Lazarević Kristina B., Dražić Milan S., Gligorević Kosta B., Pajić Miloš B.
• Format: Article
• Language: English
• Published: VINCA Institute of Nuclear Sciences 2020-01-01
• Series: Thermal Science
• Subjects: vacuum drying; freeze drying; bee honey; drying kinetics; quality parameters
• Online Access: http://www.doiserbia.nb.rs/img/doi/0354-9836/2020/0354-98362000194N.pdf

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.