Rheology and botanical origin of Ethiopian monofloral honey

Rheology and botanical origin of Ethiopian monofloral honeys were investigated using harmonized method of melissopalynology and HAAKE VT 500 over a temperature range of 25-45 degrees C, respectively. The percent dominance of monofloral honeys ranged from 59.8% (Croton macrostachyus) to 903% (Schefflera abyssinica). Botanical origin and geographical location of honeys were categorized on principal component analysis (PCA) of pollen data. The PCA graph showed that honeys were divided into two separate groups or three sub groups, based on their close appearance in the plot. The highest viscosity value was observed in Eucalyptus globulus honey and the lowest in Vemonia amygdalina. Shear stress versus shear rate linearity indicated that all the monofloral honeys exhibited Newtonian behavior. The effect of temperature on the viscosity of honey followed the Arrhenius relationship. The activation energy ranged from 60,042.05 (Eucalyptus globulus) to 9858.741 kJ/mol (Vemonia amygdalina). Viscosity of honey was found to be time independent. (C) 2016 Elsevier Ltd. All rights reserved.