The sugars of honey—A review

Abstract

Surveys of floral honey composition have established that the three major components are fructose, glucose, and water, averaging 38.2, 31.3 and 17.2%, respectively. Glucose and fructose are the only monosaccharides in honey and it is these sugars, combined in various forms, that comprise the di-and trisaccharide fractions of floral honey. Several laboratories, utilising various chemical and physical methods, have been responsible for the isolation and characterisation of ten disaccharides, ten trisaccharides, and two higher sugars from floral honey. Several of these occur only rarely in nature, and the trisaccharide erlose, produced by the action of honeybee invertase on sucrose, was first discovered as a component of honey. Honeydew honey is produced by the honeybee from honeydew deposits left by various hemipterous insects on their host plant. Honeydew contains a more complex mixture of sugars than does nectar, and honeydew honey is appreciably higher in reducing disaccharides and higher sugars than is floral honey. The trisaccharide melizitose, not found in floral honey, is often present in levels exceeding 10% in honeydew honey. The precipitation of glucose from honey, termed granulation, is often technologically undesirable as it is sometimes followed by fermentation. Indices such as the glucose/water ratio have been used to predict granulation tendency. Small amounts of hydroxymethylfurfural (HMF) occur naturally in honey, resulting from the acid catalysed dehydration of the hexoses, particularly fructose. High levels of HMF suggest adulteration of honey with acid inverted invert syrup and several methods are available for its determination. The conversion of nectar and honeydew to the complex array of honey sugars by the honeybee involves a variety of chemical and biochemical processes, some of which are now understood, while others remain to be elucidated.

Improved detection of honey adulteration by measuring differences between13C/12C stable carbon isotope ratios of protein and sugar compounds with a combination of elemental analyzer - isotope ratio mass spectrometry and liquid chromatography - isotope ratio mass spectrometry (δ13C-EA/LC-IRMS)

“…The comparison of the results with the naturally occurring values (Bogdanov et al, 2003;Doner, 1977;Lipp, 1994;Persano Oddo and Piro, 2004;Swallow and Low, 1994;Von der Ohe et al, 1991;White, 1992b;White and Siciliano, 1980) can hint at a possible adulteration. However, this procedure is time-consuming and only Table I.…”

Pharmacophagy and pharmacophory: mechanisms of self-medication and disease prevention in the honeybee colony (Apis mellifera)

“…In addition, it also comprises, at a much lower level, di-and polysaccharides, minerals, amino acids and even some proteins (Crane 1975;Doner 1977). The high sugar concentration results in a strong osmotic pressure lethal for any microbe (except for symbiotic lactic acid bacteria, Olofsson and Vásquez 2008).…”

The effect of different dietary sugars and honey on longevity and fecundity in two hyperparasitoid wasps

“…Honey has long been used in the lab as an alternate food source to sucrose solution for insects such as parasitoids, but its actual properties in influencing parasitoid reproduction and longevity have been little explored. With respect to carbohydrates, honey consists mainly of similar proportions of fructose and glucose with smaller concentrations of maltose, sucrose, and several other complex carbohydrates (Doner, 1977). As with all nutritive sweeteners, the content of honey is dominated by sugars although it also contains trace amounts of vitamins or minerals (Martos et al, 2000;Gheldof et al, 2002).…”