Antioxidant Properties, Polyphenol Content and Colorimetric Characteristics of Different Floral Origin Honeys from Different Areas of Southern Italy.

Ninety honey samples of five different floral origins (chestnut, eucalyptus, citrus, multifloral and sulla) from nine areas of southern Italy, were screened to evaluate the polyphenol content by spectrphotometric methods, the antioxidant activity by ABTS (2,2’-azino-bis-(3-ethylbenzothiazoline-6-sulfonic acid)) diamonium salt, FRAP (ferric reducing antioxidant power) and DPPH (1,1-diphenyl-2-picrylhydrazyl) assays, and the colorimetric characteristics by spectrophotometric and CIE (Commission Internationale de l'Eclairage) L*a*b* methods. Moreover, the correlations between the analysed parameters were studied. Overall, the results showed that all the honey samples presented high total phenolic and flavonoid contents (12.23 mg gallic acid equivalent/100g honey and 8.16 mg quercetin equivalent/100g honey, respectively), and a high antioxidant activity (59.17%, 66.50% and 349.11 μM Fe (II) for ABTS, DPPH and FRAP assays, respectively), but those results differ widely according to the honey types, suggesting that honey composition has been influenced by its floral and geographical origin. In particular, the darkest honeys, such as chestnut honey (L* = 59.94; 1.26 AU), showed the highest polyphenol content and the highest antioxidant activity. Honeys from the areas with major anthropogenic activities and high population density presented the highest antioxidant activity. Correlations between the analysed parameters were statistically significant (P < 0.05), suggesting that the polyphenol content is correlated with the antioxidant activity and colour of honey.