Metal content of Southern Italy honey of different botanical origin and its correlation with polyphenol content and antioxidant activity

Seventy-eight honey samples from five different floral sources and from nine geographical areas, all over Southern Italy, were analyzed to determine the polyphenolic and mineral contents, colour characteristics and antioxidant activity. Three different methods were used for evaluation of the antioxidant power: ABTS, DPPH and FRAP assays. Results show that the darkest colored honey, such as chestnut honey, have the highest polyphenolic and minerals contents as well as the highest antioxidant activity. The honey from areas with greater anthropogenic activities (Penisola sorrentina, Tarantino) had a higher mineral content, especially heavy metals, and high antioxidant activity. A high correlation was observed between polyphenol content and antioxidant activity, in particular r = 0.66 between flavonoids and FRAP assay. Also, the antioxidant activity showed, a marked correlation with the metals. Results suggested that the honey samples have high nutritional and nutraceutical characteristics and can be used as indicators of environmental pollution.