Physicochemical characteristics and antibacterial activity of Honey from Kotido District

Abstract

In this study, eight (8) honey samples from Kotido district, North Eastern Uganda, were studied to characterize their physicochemical properties (honey color, honey pH, phytochemical composition) and antibacterial activity. Colorimetric analysis identified 3 honey colors: extra light amber (50%), amber (35%) and light amber (15%), attributed to the district’s semi-arid climate and rich vegetation composed of medicinal plants. Phytochemical quantification revealed high concentrations of alkaloids with mean of 657.66 ±22.24 mg/ml) and low mean concentration of flavonoids of 48.88 ±3.73 µg/ml. This suggests that honey from Kotido has both antioxidant and antibacterial potential. The mean pH of the samples was 3.30±0.08 and there was significant differences in pH was (p<0.001, 95% CI. Generally, amber honeys had slightly higher mean pH (3.46±0.08) compared to extra light amber honey (3.15 ± 0.1) hence supplementing on the antibacterial potential. The mean zone of inhibition on Escherichia coli ATCC 25922 was 8.75±1.03mm while that on Staphylococcus aureus ATCC 25923 was 9±0.58mm. Amber and extra light honeys showed stronger antibacterial with mean MIC and MBC of 392.86±50.51 mg/ml and 392.86±50.51 mg/ml respectively compared to light amber honey mean MIC and MBC of 500±0mg/ml and 500±0mg/ml respectively due to high alkaloid and flavonoid content in them. These findings indicate that Kotido honey can be used for medicinal applications as an antioxidant and against susceptible bacterial infection. The three honey colors reported for the first time in Karamoja region suggests potential for specialty honey brands, with potential economic value. However, study limitations such as small sample size, unclear harvesting season and unclear storage conditions should be addressed in subsequent studies in order to provide a good representation of honey production in Kotido district.