Investigation of total polyphenol, antioxidant activity, and levels of metals in Ethiopian commercial beers

Abstract

Abstract: Total polyphenol, antioxidant activity, and heavy metal contents in selected Ethiopian beers (Dashen= B1, Harar = B2, Habesha= B3, Saint George= B4, and Walya= B5) were investigated. The average concentration of total phenolic content in B1, B2, B3, B4, and B5 were found to be 219.80, 206.09, 190.24, 193.00, and 212.10 mg GAE/L, respectively. The obtained results showed that B1 contained significantly highest total polyphenol content (219.80±2.83 mg/L) and showed the highest radical scavenging capacities (84.16±0.65). According to Pearson’s correlation between polyphenol extract with antioxidant activities, suggested that phenolic compound in beer were contributor to antioxidant activity. Similarly, all the beer samples were analyzed for Cd, Cr, Cu, Ni, and Pb with flame atomic absorption spectrophotometer. The total metal concentrations of Cd, Cr, Cu, Ni, and Pb were found to be in the range of (ND–0.022 mg/L), (0.02 −0.041), (0.023-0.054), (ND- 0.064), and (ND-0.022 mg/L), respectively. The efficiency of the procedure was validated by spiking and the percent recovery of the metals varied from 90.9 to 104.3%.