Abstract
Different factors are known to affect the chemical constituents of the bees honey including the climate and the floral origin. The objective of this study was to investigate the effect of floral origin and altitude on some physiochemical properties of honey samples from the south western part of Saudi Arabia. The investigated physiochemical properties were the pH, conductivity and the concentration of hydrogen peroxide and dicarbonyl molecules. Fifteen Ziziphus spina christi honey samples were collected from three different altitudes in Asir Region (113, 317 and 511 meters above sea level) and twenty fiveAcacia spp honey samples (14, 113, 567, 576 and 2247 meters above sea level). Honey pollens were analyzed to confirm the botanical origin of the honey samples. The pH and conductivity of the honey were determined and compared to three honey standards (Gulf countries standards, CODEX and USA national honey board). The hydrogen peroxide percentage (ww) was determined by titration with ceric sulfate and ferroin as indicator while the dicarbonyls were determined as glyoxal equivalent using spectrophotometer. The pH and conductivity were measured using pH meter and conductometer. The SPSS version 20 program was used for the analysis of the obtained results. The honey samples contained high amounts of the plants pollens and the pH and conductivity were within the standards ranges. The Ziziphus honey was characterized by significantly high mean percentage of hydrogen peroxide (3.9% ± 2.2) compared to the Acacia honey (2.5% ± 0.83) and the Acacia honey contained the highest mean concentration of the dicarbonyl molecules (278.7mg/100g ± 278.4) compared to (147.6mg/ 100g ± 93.2) in the Ziziphus honey. Regarding the effect of altitude, the high altitudes were characterized by low concentrations of hydrogen peroxides and high concentration of dicarbonyl molecules. The altitude significantly increased the dicarbonyl molecules concentration and significantly decreased the hydrogen peroxide percentage.The Ziziphus honey was characterized by significant high percentage of hydrogen peroxide while the Acacia honey was characterized by significant high concentration of dicarbonyl molecules.