Objective Honey from stingless bees has strong antioxidant qualities due the presence of phytochemical substances, especially phenolic and flavonoid compounds. This study aimed to determine phenolic, flavonoid content, color intensity and antioxidant activity of stingless bee honey (SBH). Methodology Fifty-seven SBH samples were collected from four regional states of Ethiopia representing various geographical origins. The total phenolic content (TPC) was determined using 25 to 75 mg gallic acid/100 g of honey. The total flavonoid content (TFC) was determined by adding 5 mL of a honey solution to 5 mL of 2% aluminum chloride (AlCl 3 ) in a standard procedure using colorimetric methods. The free radical scavenging activity of honey samples was estimated by using 2,2-diphenyl-1-picrylhydrazyl (DPPH). Results The SBH's average phytochemical composition and antioxidant activity were as follows: TPC (42.3 mg GAE/100 g), TFC (54.6 mg QE/100 g) and DPPH activity (112.1 mg of ascorbic acid equivalent/100 g). The phytochemical composition and antioxidant activity of SBH were: TPC (73.8 mg GAE/100 g), TFC (86.6 mg QE/100 g) and DPPH activity (165.8 mg of ascorbic acid equivalent/100 g) respectively. The present results showed that the phenolic and flavonoid contents and antioxidant activity of SBH varied significantly among the sampling areas. Phenolic and flavonoid compounds were the most abundant in dark amber honeys, however the amounts varied widely. Additionally, dark amber honeys showed higher antioxidant qualities. The statistical analysis showed a positive relationship between color intensity, phenolic and flavonoid content and antioxidant activity. Conclusion Particularly, M. beccarii honey exhibited remarkable quantities of phenolic and flavonoid contents and antioxidant activity. SBH generated from the two stingless bee species, has promising phenolic and flavonoid content and antioxidant qualities. Further study on the physiology of the active ingredients on the Ethiopian SBH is recommended to discover the benefit for human therapy.
Negera et al. (Thu,) studied this question.