Physicochemical properties and biological activities of Thai originated honeys

Abstract

Honey harvested from different sources has different physicochemical and biological characteristics, biologically active compounds present in honeys, especially the group of antioxidants. This research studied on honeys produced from three different sources including para rubber, rambutan and longan. The results of physical and chemical analysis including moisture content, color, electrical conductivity, pH, viscosity, proline content and sugar content were found that they are in ranged of 14.84-17.80, 22-44 Pfundscale, 0.325-0.518 mS/cm, 4.04- 4.27, 2,755.67-3,220.33, 116.25-785.75 and 71.38-73.21%, respectively. The obtained values from experiment were in the standard range of natural honey. Rambutan honey has the highest sugar content of 73.21% and longan honey has the highest content of oligosaccharides of 2.78% as well as highest proline content of 787.75 mg/kg. Analysis of phenolic and flavonoid compounds were found that longan honey contained more phenolic and flavonoid compound than others two honeys. Analysis of enzyme activities in honey including diastase and invertase the results showed that both enzymes are in the ranged of 6-12 Gothe Scale and 36.87-147.02 Unit/Kg honey, respectively. Analysis of antioxidant activities, the 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) scavenging activity, ferric reducing antioxidant power (FRAP), and ferrous chelating showed that longan honey showed better antioxidant capacity than rubber and rambutan honeys. Longan honey had highest antidiabetic activity. Prebiotic property of oligosaccharide in honey was studied by in vitro batch fermentation. The oligosaccharides was separated by activated charcoal filtration. The result showed that oligosaccharides presented in longan honey able to significantly stimulated microorganisms growth which were Bifidobacteria spp. and Lactobacillus spp. similar to that result of fructooligosaccharides fermentation oligosaccharide in longan honey also able to increase SCFA such as butyric acid, acetic acid and propionic acid