Analysis of Bactericidal Components in Japanese Honeys

It is known that the factors identified as contributing to the bactericidal activity of honeys are the high sugar concentration, hydrogen peroxide (H2O2) and low pH, and its bactericidal components depend on honey plant and natural environment. Manuka honey has been studied a lot about bactericidal effect. However, since Japanese honeys are mainly used as food, detailed analyzes of bactericidal components and its actions have not been reported. Therefore, we analyzed bactericidal components contained in nine Japanese honeys using Lucigenin-CL-HPLC. As our results, four species components of H2O2, glucose, fructose and methylglyoxal were detected from nine Japanese honeys. The H2O2 concentrations were 4.1 × 10-5 - 1.8 × 10-4 mol/L, the glucose concentrations were 1.4 - 2.8 mol/L, the fructose concentrations were 1.9 - 2.4 mol/L, the methylglyoxal concentrations were 4.0 × 10-3 - 1.6 × 10-2 mol/L. In this study, we confirmed that methylglyoxal is also contained in Japanese honeys, although it is a bactericidal component which is reported to be characteristic of manuka honey. It is considered that the further study of Japanese honeys is useful for more safe use, quality control, and clinical application.