Water determination in honey—Karl Fischer titration, an alternative to refractive index measurements?

Honeys must not contain too much water if they were to be protected from microbiological spoilage. Water content is usually measured via the refractive index (RI). From the value measured, the water content is calculated by an empirical formula or by “conversion” tables. Creamy honeys must be heated before analysis, a procedure that may result in a loss of water and makes a comparison with liquid honey measurements at room temperature difficult. Another problematic point is that the composition of the solid content, which in fact is determined by RI measurements (and not water content), varies from one type of honey to another. The formula used for calculation and the tabulated values are therefore necessarily not equally correct for every honey. The objective of this work was to establish a generally applicable method to determine the real water content of honeys. As the Karl Fischer (KF) titration is known to determine the water selectively by a chemical reaction, this technique was chosen.