Total phenolic, flavonoids and some selected metal content in honey and propolis samples from South Wolo zone, Amhara region, Ethiopia

Abstract

Ethiopia is endowed with a variety of multifloral origin of honey and propolis. However, there is paucity of information on the chemical composition of honey and propolis for some of the regions. For this study, seven different types of honey and three propolis samples were collected from South Wolo zone districts of the Amhara region, Ethiopia. The total phenolic and flavonoids contents were estimated spectrophotometrically, while eight metal contents were analyzed using ICP-OES. Both honey and propolis samples were found to be rich in total phenolic content expressed as gallic acid equivalent (GAE) ranged from 45.42 to 73.51 mg GAE/100 g of honey and 204.4 to 262.5 mg GAE/100 g of propolis samples. The total flavonoids content expressed as catechin equivalent (CE) ranged from ND to 55.73 mg CE/100 g of honey and 187.7 to 214.9 mg CE/100 g of propolis. The mineral contents in the honey samples were in the range of 25–65 µg/100 g, 10–113 µg/100 g, 3.75–17.5 µg/100 g, 132.5–296.3 µg/100 g, 250–910 µg/100 g, and 807.5–6860 µg/100 g, respectively, for Cr, Co, Cd, Mg, Ca, and Fe. However, Ni and Cu were not detected in the samples. Cd was found below the maximum permissible limit. Thus, the honey samples collected from South Wolo zone of the Amhara region, Ethiopia are of good quality in terms of heavy metal contamination and contained relatively good composition of phenolic compounds as compared to some honey samples reported from overseas.