Investigation of Physicochemical Characteristics and Heavy Metal Contamination in Honey from Selected Districts of the Tigray Region, Ethiopia

Abstract

This study was conducted to assess the physicochemical properties and heavy metal concentrations in honey sourced from selected districts in the Tigray Region of Ethiopia. A cross-sectional study was conducted from January 2024 to December 2024, in which representative pooled honey samples (500 grams per district) were collected from six purposively selected districts. The physicochemical parameters: hydroxymethyl furfural (HMF) levels, free acidity, color, moisture content, electrical conductivity, ash content, and pH were analyzed, while concentrations of metals were also determined using flame atomic absorption spectrometry (FAAS). The findings revealed moisture content ranging from 16.8% to 20.5%, electrical conductivity between 0.215 and 0.645 mS/cm, pH values from 4.44 to 5.505, free acidity levels between 8.5 and 23 meq/kg, ash content from 0.045% to 0.29%, and HMF concentrations ranging from 0.8 to 15.95 mg/kg. The physicochemical characteristics of the honey complied with European, national, and Codex Alimentarius standards, confirming its quality and safety for human consumption. The validity of the analytical methods was confirmed by recovery rates for heavy metals ranging from 95.5% to 105% in spiking experiments. The highest concentration of heavy metals was found for iron (Fe), which ranged from 6.58 to 25.36 mg/kg, followed by manganese (Mn) at 0.06–2.74 mg/kg, zinc (Zn) at 0.01–1.90 mg/kg, and copper (Cu) at 0.04–0.19 mg/kg; lead (Pb) and chromium (Cr) were not detected in any samples, indicating the absence of these potentially toxic heavy metals in the honey analyzed. Overall, these findings are suggesting a good quality of honey production in the study area. However, regular monitoring of both physicochemical properties and heavy metal levels in honey is crucial for ensuring consumer safety and maintaining market standards, alongside further research into honey quality and safety practices.