Physicochemical Analysis And Determination Of Some Essential And Non-Essential Heavy Metals In Honey Samples In Two Districts Of West Shewa Zone, Oromia Regional State, Ethiopia

Abstract

Honey is a sweet, naturally and sugary substance. It is produced by bees from the nectar of different plants. Honey contains different sugars, organic acids, proteins, vitamins, minerals, and heavy metals. This study was conducted for the physicochemical analysis and determination of some essential and non-essential heavy metals in the honey sample collected from two districts in the west Shewa zone, Oromia region, Ethiopia. The districts were selected purposively based on honey production capacity, namely the Nono and Dano districts. There hasn't been any research on honey done in this area. Four homogenized honey samples (one white and one red) were collected randomly from each of the Woreda markets. The physicochemical parameters analyzed could be summarized by the ranges of each variable as: pH 3.24–3.9, ash content 0.2-1.2%, moisture content 12.9–19.47%, free acidity 30–38.5 meq/kg, electrical conductivity 479.7–680 μS /cm, total sugars from 64.55–70.64%, reducing sugar from 62.11–65.6%, and non-reducing sugar from 2.44–4.95%. On the other hand, the honey samples were digested prior to heavy metal analysis, following an optimized procedure. The levels of selected heavy metals were determined by using atomic absorption spectrophotometer. The percentage recovery for metal analyses was 96.69%–103.3%. The precision was tested in terms of relative standard deviation (<15%), indicating good accuracy and precision of the method for heavy metal analysis in honey samples. The analysis of Zn, Cu, Cd, Ni, Cr, and Fe was obtained by using a flame atomic absorption spectrophotometer and indicated that the concentrations ranged from 2.51 to 11.08, 0.52 to 1.7, ND-0.30, ND-9.27, ND-4.78, and 1.42 to 19.94 mg/kg with mean concentration ranges, respectively. Pb and Mn were the only metals not detected in all analyzed honey samples. The highest concentrations were observed for iron, nickel, zinc, copper, chromium, and cadmium in that order. Essential heavy metals (Zn, Fe, and Cu) were found in all analyzed honey samples. The highest concentration of metals was observed in Dano district honey. The concentration of heavy metals found in all honey samples was below the W0rld Health Organization recommended limit and Codex Alimentarius Commission standard, except for Fe and Cd from the Dano district.