HMF
Hydroxymethylfurfural (5-hydroxymethyl-2-furaldehyde, HMF) is an organic compound that is produced by acid-catalysed dehydration of sugars, primarily fructose and its measurement is crucial to evaluate the conformity of honey for daily use according to government legislation. Elevated concentrations of HMF in honey provide an indication of overheating, poor storage conditions, possible adulteration with other sugars or syrups and/or higher age of the honey.
The Codex Alimentarius (Alinorm 01/25 2000) states that the HMF content of honey after processing and/or blending must not be higher than 80 mg/kg. The European Union (EU Directive 110/2001) has fixed a HMF limit in honey of 40 mg/kg with the following exceptions: 80 mg/kg for honey coming from Countries or Regions with tropical temperatures, 15 mg/kg for honey with low enzymatic level (8-3 Schade Units).