- 5 - (hydroxymethyl )-2- furaldehyde
- 5 - ( hydroxymethyl) furfural
1.21 g · cm -3
32-35 ° C
114 ° C ( 1.3 hPa)
2500 mg · kg -1 ( LD50, rat, oral)
Template: Infobox chemical / molecular formula search available
Hydroxymethylfurfural, HMF and 5 - ( hydroxymethyl) furfural aldehyde and a furan compound which is formed during the thermal decomposition of sugars or carbohydrates. HMF can be detected, etc. In many heat -treated foods, including milk, fruit juice, alcoholic beverage, honey,. Recent studies examine the determination of HMF in cigarettes. In its chromatographic behavior similar to the HMF, patulin, so care must be taken when detecting, do not confuse the two compounds. HMF can be used as starting material for the manufacture of plastics. Hexoses, especially fructose, are converted by dehydration with acid into HMF.
The organic compound was investigated in 1912 by the French chemist Louis Maillard in the context of his research on non-enzymatic reactions of glucose and lysine.
In a one-step synthesis, in the presence of cellulose coupled copper (II) -chlorid/Chrom (II ) chloride catalyst in the ionic liquid 1-ethyl- 3- methylimidazolium chloride as a solvent at 80-120 ° C to 5-hydroxymethylfurfural (HMF ) are implemented. Under these conditions, the synthesis is about ten times faster than with a conventional acid-catalyzed hydrolysis.
Also hydroxymethylfurfural produced in the course of a caramelization.
In 2007 U.S. chemists have presented a method to Conrad Zhang of the Institute of Surface Catalysis in Richland ( Washington State ) in the U.S. journal Science, with whom she Products manufactured from glucose, which have hitherto been mainly produces petroleum-based. In their reaction vessels of sugar directly into the molecule hydroxymethylfurfural ( HMF) is converted.
HMF in honey
A small amount of HMF in honey is an indicator of its freshness and naturalness. A high HMF value indicates excessive heating or storage. When honey is heated, formed from fructose HMF. The HMF content in freshly vibrated honey is very low and increases if stored correctly, depending on pH and storage temperature by about 2-3 mg of / kg per year. Store at room temperature (21 ° C) can the HMF content increases kg in a year already at 20 mg / kg. The EU has a HMF maximum limit of 40 mg / kg for honey, produced under European conditions specified. Some national associations of beekeepers to ask for even lower values , for example, allowed the German Beekeepers Association more than 15 mg / kg for his seal of approval "Genuine German honey ".
HMF in honey is usually detected by high performance liquid chromatography or the so-called Winkler method. Since 2009, a rapid test of Merck KGaA for the determination of HMF is available. In the " Reflectoquant ® HMF " said test a small amount of honey is diluted 1:4 with distilled water, dipped a test strip into the sample and then measured in a RQflex reflectometer.
The U.S. National Institute of Environmental Health Sciences is for HMF is a high risk that it might be carcinogenic to. Reason for this is that other members of this group of compounds show carcinogenic properties. Studies on the toxicity of HMF itself, however, have been conducted only on a small scale.
The presumption of carcinogenic properties of 5 -HMF comes from older scientific studies. It is known that a similar compound, 5 - Sulfooxymethylfurfural, mutagenic and carcinogenic.
In studies of various substances with respect to cancer preventive properties, no such effect could be demonstrated for 5- HMF.
The possible misinterpretation of the carcinogenic property is based on the fact that 5- HMF only in recent years as a pure substance (99%) can be isolated. Pure 5 -HMF is a white powder and not, as erroneously assumed yellow. The yellow color refers to metabolites of 5 -HMF and other components.