Honey polysaccharides

Although the molecular weight of the polysaccharide was not determined, its rapid rate of diffusion on ultracentrifugation, and the fact that synthetic boundary-cells had to be used, indicated that the molecular weight was less than 10,000. The molecular weight of buckwheat-honey polysaccharide is 9,000. 

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Although the pyrolysis of some classes of polysaccharide materials has been studied quite extensively in the food, petrol and tobacco industry, very little has been published specifically on polysaccharide binders (arabic gum, tragacanth gum, fruit tree gum, honey and starch). The pyrolysis of glucane based polymers, especially cellulose, has been studied in detail [6,55], highlighting how anhydrosugars and furan derivatives are the main pyrolysis products, together with one-, two- and three-carbon aldehydes and acids. 

Phosphoric acid esters of the ketopentose D-ribulose (2) are intermediates in the pentose phosphate pathway (see p.l52) and in photosynthesis (see p.l28). The most widely distributed of the ketohexoses is D-fructose. In free form, it is present in fruit juices and in honey. Bound fructose is found in sucrose (B) and plant polysaccharides (e.g., inulin). 

Carbohydrates serve as a general and easily available energy source. In the diet, they are present as monosaccharides in honey and fruit, or as disaccharides in milk and in all foods sweetened with sugar (sucrose). Meta-bolically usable polysaccharides are found in vegetable products (starch) and animal products (glycogen). Carbohydrates represent a substantial proportion of the body s energy supply, but they are not essential. 

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. 

D-fructose 102 -92.4 Free in fruit juices and honey combined as in sucrose and plant polysaccharides. 

Glucose is by far the most abundant monosaccharide it occurs free in fruits, plants, honey, in the blood of animals, and combined in many glycosides, disaccharides, and polysaccharides. The structure and properties of glucose will be considered in greater detail than those of the other monosaccharides, not only because of its importance, but because much of what can be said about glucose also can be said about the other monosaccharides. 

For simple fluids, also known as Newtonian fluids, it is easy to predict the ease with which they will be poured, pumped, or mixed in either an industrial or end-use situation. This is because the shear viscosity or resistance to flow is a constant at any given temperature and pressure. The fluids that fall into this category are few and far between, because they are of necessity simple in structure. Examples are water, oils, and sugar solutions (e.g., honey unit hi.3), which have no dispersed phases and no molecular interactions. All other fluids are by definition non-Newtonian, so the viscosity is a variable, not a constant. Non-Newtonian fluids are of great interest as they encompass almost all fluids of industrial value. In the food industry, even natural products such as milk or polysaccharide solutions are non-Newtonian. 

With this volume we welcome David R. Bundle to the Board of Advisors and look forward to valuable input from the prestigious carbohydrate laboratory in Edmonton, Alberta. With regret we record the death, on April 16, 1997, of Elizabeth Percival, a noted authority on marine algal polysaccharides, and on October 14, 1997, of Iqbal R. Siddiqui, who authored the article Sugars of Honey in Volume 25 of this series. 

Fructose is a major constituent (38%) of honey the other constituents are glucose (31%), water (17%), maltose (a glucose disaccharide, 7%), sucrose (a glucose-fructose disaccharide, 1 %), and polysaccharide (1 %). The variability of these sugars in honey from different sources is quite large. 

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