Evaluating the antioxidant activity and the level of 5-hydroxymethylfurfural in honey

Abstract

Honey is one of the richest sources of antioxidants due to a variety of phenolic acids and flavonoids.Another prime chemical indicator of assessing honey quality is 5-hydroxymethylfurfural (HMF)which indicates the freshness of honey as well as exposure to heat. Increasing HMF above thepermissible limit could cause cytotoxic and mutagenic effects. In this study, we evaluate theantioxidant activity and radical scavenging capacity of forty samples of natural and commercialIranian honey. Also, we determine the HMF content in these samples. This aim was achievedthrough ferric reducing antioxidant power (FRAP), 1, 1-diphenyl-2-picrylhydrazyl (DPPH) assay,and white methods. Results of DPPH (in the range of 3.13% to 66.61%) revealed there was nosignificant difference between natural and commercial honey in terms of radical scavenging activity(p˃0.05). On the other hand, the results of FRAP showed that natural honey had a significantlyhigher total antioxidant capacity than commercial honey (p˂0.05). There was a significant differencebetween honey samples from different plants, too. Furthermore, there was a significant differencebetween natural and commercial honey in terms of radical scavenging activity and HMF levels(p˂0.05). The result of HMF content was in the range of 8.64 to 98.48 mg/kg. Eventually, it couldbe concluded that climate, plant source, process of production and storage have an impact on theseparameters. Also, some honey samples have high HMF content due to heat-treated processes ordated products.