PHYSICOCHEMICAL PROPERTIES AND BIOFUNCTIONAL ACTIVITIES OF TWO MONOFLORAL HONEYS FROM SOUTHWEST ETHIOPIA: THE CASE OF JIMMA ZONE

Honey is a sweet, viscous substance produced by honey bees from the nectar of plants or secretion fromplants or plant-sucking insects. Honeys from different botanical origins may vary in their chemical composition, flavor and color. In this study, Coffea arabica and Vernonia amygdalina honey of Ethiopia investigated. Moisture, sugars, electrical conductivity, ash, pH, free acidity, hydroxymethylfurfural, specific rotation, diastase and invertase activity were determined using AOAC method. Phytochemicals and antioxidant activities were determined using UV-visible spectrophotometer. Antibacterial activity determined using disc diffusion method. Sensorial analysis was done using triangle test panel. Glycemic index investigated using human model. Melissopalynology result showed thatCoffea arabica (54.4 to 94.2%) and Vernonia amygdalina (47 to 68.8%) were dominated honeys. It was found that Coffea arabica honey contain higher free acidity(33.74±5.3 meq/kg), hydroxymethylfurfural(5.6±2.52 mg/kg), Invertase activity (14.12±2.25 IN) andcaffeine(96.11±20.02mg/kg). The higher moisture (19.02±0.05g/100g), pH (4.52±0.02), specific rotation (-5.98±0.07[α]D20) and diastase (12.5±0.55˚schade) was found in Vernonia amygdalinahoney. Fructose was the dominant sugar in the monofloral honeys. Highertotal phenol (34.26±0.98 mgGAE/100g) and total flavonoid (93.48±1.67mgCEQ/100g) was found in Vernonia amygdalina honey and it showed stronger DPPH scavenging activity (45.94%) than Coffea arabica honey.Stronger ferric reducing antioxidant power (22.71±10 mg AAE/100g) was found in Coffea arabica honey. Vernonia amygdalina honey showed better inhibition against Staphylococcus aureus (10.21±0.89mm) and Escherichia coli (6.75±0.22mm) at 50% honey concentration. Based on triangle test, 94.44% of the panelist identified the bitter test feeling immediately after swallowing for Vernonia amygdalina honey