Effect of hot air drying on quality characteristics and physicochemical properties of bee pollen

Abstract

The aim of this study was to investigate the effect of hot air drying on quality characteristics, physicochemical properties, morphological structure and organoleptic characteristics of bee pollen, and compute the effective moisture diffusivity and activation energy during hot air drying of bee pollen. Bee pollen samples were dried at 40, 45, 50, 55 and 60 degrees C. Effective moisture diffusivity (D-eff) values ranged from 1.38 x 10(-10) to 4.00 x 10(-10) m(2)/s, and the activation energy (E-a) was found to be 42.96 kJ/mol. Protein, fat, total carbohydrates and vitamin C of bee pollen were affected by the drying temperature. Dried bee pollen samples had high solubility index, and had lower L* and b* values as compared with those of the fresh bee pollen. Total color difference (Delta E) was the lowest for the bee pollen dried at 40 degrees C. Morphological changes on dried bee pollen surfaces increased with increasing the drying temperature. Bee pollen dried at 40 degrees C took the highest sensory scores and retained its quality attributes better than the bee pollen samples dried at 45, 50, 55 and 60 degrees C. Hot air drying at 40 degrees C is recommended for the drying of bee pollen.