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 (0.405-0.427aW) and effective moisture diffusivity coefficient (8.26?10- -9.51?10-7[m2s-1]). The HPLC 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. [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]

Drying Kinetics and Shrinkage Analysis of Valeriana Officinalis Roots