Evaluation of the Phenolic Content, Antiradical, Antioxidant, and Antimicrobial Activity of Different Floral Sources of Honey

Abstract

Thirty-five honeys were evaluated for total phenolic content by Folin-Ciocalteu method, for potential antioxidant activity using phosphomolibdenum assay and by the 1,1-diphenyl-2-picrylhydrazyl method for antiradical activity. The antimicrobial activity was studied by the agar diffusion method, using 12 bacteria and 2 yeasts. The means of the total phenolic contents of chestnut, honeydew, multifloral, thyme, and astragalus were 47 +/- 18, 24.2 +/- 0.6, 14 +/- 11, 11 +/- 6, and 9 +/- 7 mg/100 g honey as gallic acid equivalent, respectively. The lowest antioxidant activity was observed in honeydew 70 +/- 5 mg ascorbic acid equivalent/g honey while the highest content was observed in astragalus honey 86 +/- 16 mg ascorbic acid equivalent/g honey. Correlation between the phenolic content and antioxidant activity were found to be statistically significant. Chestnut honeys (n = 5) exhibited maximum free radical scavenging activity with an average 68 +/- 9%. The honey samples showed the highest antimicrobial activity against some microorganisms, especially Escherichia coli O157:H7, Salmonella typhimurium, Staphylococcus aureus, Listeria monocytogenes, and Proteus mirabilis. On the other side, Aeromonas hydrophila, Bacillus subtilis, and E. coli were the most resistant microorganisms. The results revealed that the Turkish honeys studied proved to be a good source of antioxidant and antimicrobial agents that might serve to protect human health.