Glucose in honey

Cavia, M. M., Fernandez-Muino, M. A., Gomez-Alonso, E., Montes-Perez, M. Huidobro, J. F., and Sancho, M. T. (2002). Evolution of fructose and glucose in honey over one year Influence of induced granulation. Food Client. 78,157-161. 

A.N. Batsoulis, N.G. Siatis, A.C. Kimbaris, et al., FT-Raman spectroscopic simultaneous determination of fructose and glucose in honey, J. Agric. Food Chem., 53, 207-210 (2005). 

Dextrin.—The polarisations of solutions of honey before and after inversion furnish an indication of the presence or absence of dextrin, and, indirectly of that of commercial glucose, in honey. If the honey has a marked laevo-rotation, the presence of dextrin may be excluded, but if the rotation is either feebly negative or positive, a test should be made for dextrin, although some natural honeys free from dextrin do show similar behaviour. 

Matsumoto et al (41) prepared a multi-enzyme electrode using glucose oxidase, invertase, mutarotase, fructose-5-dehydrogenase, and catalase to simultaneously detect glucose, fructose, and sucrose in fruit juices and soft drinks. Detection of multi-components by enzyme sensors was also reported in analysis of sucrose and glucose in honey (42) and drinks (43), and L-malate and L-lactate in wines (44). 

Fructose, present with glucose in honey, reacts with Benedict s reagent. Circle the structural features that enable fructose to react. 

Dextrose (D-glucose) is by far the most abundant sugar in nature. It occurs either in the monosaccharide form (free state) or in a polymeric form of anhydrodextrose units. As a monosaccharide, dextrose is present in substantial quantities in honey, fmits, and berries. As a polymer, dextrose occurs in starch, cellulose (qv), and glycogen. Sucrose is a disaccharide of dextrose and fmctose. 

Sucrose, the compound we call sugar, is the most common disaccharide. One of the monomer units in sucrose is a-glucose. The other is fructose, a monosaccharide found in honey and natural fruit juices. 

Honey is primarily fructose and glucose (in that order), with a little sucrose (about 1 percent), less than 10 percent other sugars, and about 17 percent water. 

D-Fructose Fruit juices. Honey. Hydrolysis of cane sugar and of inulin (from the Jerusalem artichoke). Can be changed to glucose in the liver and so used in the body. Hereditary fructose intolerance leads to fructose accumulation and hypoglycemia. 

It is well known that heating of honey resrrlts in HMF, which is formed dming acid-catalysed dehydration of hexoses [6]. The presence in honey of simple sugars (glucose and fructose) and mar r acids is a favotrrable condition for the production of this substance. 

The initial HMF content in all honey samples was lower than the allowed maximum limit of 40 mg/kg as recommended by Turkish Alimentarus Codex [17], for honey in general. These results contradict the observation made by some authors that the types of honey produced in subtropical climates have high HMF exceeding 40 mg/kg [18]. However, the European Union council directive also allows for a maximum of 80 mg/kg for honey from tropical climates. The HMF level in honey is said to depend on the type of sugar present in honey and the fructose glucose ratio [19]. The HMF formation results from the acid catalyzed dehydration of hexose... 

Fructose is found in honey and fruit and as part of the disaccharide sucrose (common table sugar). Sucrose is hydrolyzed by intestinal brush border sucrase, and the resulting monosaccharides, glucose and fructose, are absorbed into the portal blood. The liver phosphorylates frurtose and cleaves it into glyceraldehyde and DHAP. Smaller amounts are metabolized in renal proximal tubules. The pathway is shown in Figure 1-12-7 important enzymes to remember are ... 

The main compounds in honey are glucose and fructose, and their ratio can be used as a check for authenticity regarding their botanical origin [49], as shown for some honeys in Table 19.2. 

The present challenge is to determine, quantitatively, most, if not all, of the sugars in honeys, and not merely to determine the content of D-glucose and D-fructose by yet another method. 

A Taste of Honey The fructose in honey is mainly in the jS-D-pyranose form. This is one of the sweetest carbohydrates known, about twice as sweet as glucose. The jS-D-furanose form of fructose is much less sweet. The sweetness of honey gradually decreases at a high temperature. Also, high-fructose corn syrup (a commercial product in which much of the glucose in corn syrup is converted to fructose) is used for sweetening cold but not hot drinks. What chemical property of fructose could account for both these observations ... 

About ten percent of the calories contained in the Western diet are supplied by fructose (approximately fifty g/day). The major source of fructose is the disaccharide sucrose, which, when cleaved in the intestine, releases equimolar amounts of fructose and glucose (see p. 86). Fructose is also found as a free monosaccharide in high-fructose corn syrup (55 percent fructose/45 percent glucose, which is used to sweeten most cola drinks), in many fruits, and in honey. Entry of fructose into cells is not insulin-dependent (unlike that of glucose into certain tissues, see p. 95), and, in contrast to glucose, fructose does not promote the secretion of insulin. 

Monosaccharides Glucose and fructose are the principal mono saccharides found in food. Glucose is abundant in fruits, sweet corn, corn syrup, and honey. Free fructose is found together with free glucose and sucrose in honey and fruits... 

D-Fructose (Fru), a ketose that is a close structural and metabolic relative of D-glucose. It occurs in honey and fruit juices in free form, in the disaccharide sucrose (table sugar) as a 5-membered furanose ring, and in other oligosaccharides and polysaccharides. 

Honey. A natural syrup which vanes in composition and flavor, depending upon die plant source from which die nectar was collected by die honeybee, the amount of processing, and the duration of storage. The pnncipal sugars contained in honey are fructose and glucose, the same components as in table sugar. There are minute amounts of vitamins and minerals in honey, but these are not usually considered in terms of calculating minimum requirements. 

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