TY - JOUR
TI - Study of vacuum and freeze drying of bee honey
AU - Nedić Nebojša
AU - Gojak Milan D
AU - Zlatanović Ivan J
AU - Rudonja Nedžad R
AU - Lazarević Kristina
AU - Dražić Milan
AU - Gligorević Kosta
AU - Pajić Miloš
JN - Thermal Science
PY - 2020
VL - 24
IS - 6
SP - 4241
EP - 4251
PT - Article
AB - 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.