Abstract
This study investigated the effect of 3 factors (floral source, honeybee species, and postcollection processing) that influence the antibacterial activity, free radical reduction, and other biochemical compositions of different honey types typical of Thailand. Honey samples from 3 honeybee species (Apis mellifera, Apis cerana, and Apis dorsata) were obtained from 9 floral sources (longan, wild flower, lychee, coffee, sunflower, sesame, bitter bush, para-rubber, and manuka as a control) in different regions of Thailand. These samples were evaluated for both their total and nonperoxide antibacterial activity against 10 human pathogens by agar incorporation technique. Honey samples were further analyzed to evaluate the capacity for free radical-scavenging activity, total phenolic content, and the total flavonoid contents by the 2,2-diphenyl-1-picrylhydrazyl assay, Folin–Ciocalteu method, and aluminum chloride colorimetric assay, respectively. Furthermore, the volatile organic compounds (VOCs) of Thai honey samples were investigated by headspace solid-phase microextraction and gas chromatography-mass spectrometry analysis. Findings of this study suggest a strong correlation between floral origin and honeybee species on one hand, and differences in %Brix, total acidity, protein content, antimicrobial activities, free radical reduction, phenolic, and flavonoid contents on the other hand. Moreover, VOCs of wild and coffee honey types were remarkably different, depending on the floral source. Both honeys contained characteristics of VOCs, some of which are involved in antibacterial and antioxidant activities.