Honey

Chemical Analysis of Honey

Glucose and Fructose
Sucrose
pH
Acidity
Conductivity
Moisture
Distance
Hydroxy-methyl-furfural (HMF)
Non water-soluble Solids
Council Directive 2001/110/EC on honey

Regulation (EU) 1308/2013 of the European Parliament and of the Council establishing a common organisation of agricultural markets (Beekeeping Products)

Interpretation of parameters

According to the Food and Drink Code, ‘honey is essentially composed of various sugars, mainly fructose and glucose, and other substances such as organic acids, enzymes and solid particles derived from the honey harvest. The colour of honey varies from almost colourless to dark brown. In terms of consistency, it may be liquid, viscous or partially or totally crystallised.

Honey analyses are aimed at determining its constituents and some of its physico-chemical characteristics. On the basis of these, a qualitative assessment can be made. These characteristics are linked to the type and plant origin of the honey in question.

Sugars: Honey consists mainly of sugars at a content of about 80%. Honey contains up to 20 sugars, mono-, di-, tri- and oligosaccharides. The presence of sugars in quantities other than those expected indicates adulteration.
Fructose – Glucose: the two basic sugars (monosaccharides) contained in honey. Flower honey contains more simple sugars, such as these, than honeydew honey. The glucose concentration can be used as an indicator of crystallisation. Honey with a glucose content <25% will crystallize with little or no difficulty. In contrast, a glucose content >35% will push the honey to crystallize rapidly, perhaps within a month. Intermediate values (26-29%) combined with honey moisture will drive honey to crystallization after a year.
Sucrose or sucrose: Sucrose is a disaccharide and in our daily life we find it in the form of common sugar. It is naturally present in honey in small concentrations, in the order of 2.5%. Honey with a higher than expected amount is suspected of being adulterated.
Free Acids – Acidity: Fermentation of honey causes an increase in acidity. Fermented honey has a higher free acidity. Its acidity must not have been artificially modified.
Conductivity: The conductivity of a honey is used to distinguish between flower honey and honeydew honey. Flower honeys have a conductivity of less than 0,8 mS/cm, whereas honeys from honeydew, such as pine, spruce and chestnut, have a conductivity of more than 0,8 mS/cm. Honey with a conductivity of less than 0,2 mS/cm is suspected of being adulterated.
Moisture: Refers to the percentage of water present in the honey that comes from the nectar of the plants. A low content makes handling more difficult and causes the honey to crystallize quickly. Conversely, a high content (>17%) makes honey susceptible to fermentation. Fermentation is perceived by a sour taste and bubbles – foam on the surface. Normal moisture values range between 14 – 20%.
Distance Index: Distase (or amylase) is one of the natural enzymes contained in honey. It is used as a quality criterion for detecting heat treatment. Distase, like all enzymes, is heat-sensitive and is destroyed by heating, resulting in a reduction or lack of distasis. An exception is citrus honey, in which the enzyme content is naturally low. A co-evaluation is carried out with the results of HMF.
HMF: Hydroxy-methyl-furfural (HMF) is an aldehyde resulting from the breakdown of Fructose. This decomposition takes place either by heating or by ageing and is thus an indicator of such a process. A fresh honey has a low amount of HMF. In contrast, honey with a high amount indicates possible overheating and can only be classified as industrial or confectionery honey.
Non-water soluble substances: Refers to wax and other foreign bodies that may be present in honey. A low value is obtained when the honey has been harvested by centrifugation. Conversely, honey obtained by pressing the honeycombs has a higher percentage of foreign bodies.