HMF value: indicator for freshness and storage period

Among other things the hydroxymethylfurfural (HMF) value is an indicator of the freshness and storage period of products like milk, fruit juices and honey. HMF is a decomposition product of sugars formed in honey during heat processing and storage. Testing HMF in honey is very important for determining its authenticity. Upon storage, HMF content increases by 2-3 mg/kg per year, depending on the pH value and on storage temperature. The amount of HMF present in honey is therefore an indicator of freshness and the heat processing performed on the honey, and it can be used as a guide to storage length. Some European bee federations (among them Germany, Belgium, or Italy) market a part of their honey as "quality honey" with a maximum of 15 mg HMF per kg. The EU demands a maximum of 40 mg/kg for honey produced under European conditions and 80 mg/g for honey of declared origin from regions with tropical climate.