Carbohydrate definition

Caramels, chemical nature, 222-223 Carbohydrates definition, 49-50 medical uses, 10... 

Ourane, R., Guibert, A., Brown, D., and Bomet, F., A sensitive and reproducible analytical method to measure fructo-oligosaccharides in food products, in Complex Carbohydrates Definition, Analysis and Applications, Cho, L., Prosky, L., and Dreher, M., Eds., Marcel Dekker, New York, 1997, pp. 191-201. 

Synonyms 13-[(2-0-P-D-Glucopyranosyl-a-D-glucopyranosyl) oxy] kaur-16-en-18-oic acid, p-D-glucopyranosyl ester Kaur-16-en-18-oic acid, 13-((2-0-P-D-glucopyranosyl-a-D-glucopyranosyl) oxy)-, p-D-glucopyranosyl ester Stevia Steviosin Classification Carbohydrate Definition Plant extract from leaves of Stevia rebaudiana Empirical CsaHeoOis... 

Historically, dietary fiber referred to iasoluble plant cell wall material, primarily polysaccharides, not digested by the endogenous enzymes of the human digestive tract. This definition has been extended to iaclude other nondigestible polysaccharides, from plants and other sources, that are iacorporated iato processed foods. Cellulose [9004-34-6] (qv) is fibrous however, lignin [9005-53-2] (qv) and many other polysaccharides ia food do not have fiberlike stmctures (see also Carbohydrates). 

By far the majority of carbohydrate material in nature occurs in the form of polysaccharides. By our definition, polysaccharides include not only those substances composed only of glycosidically linked sugar residues but also molecules that contain polymeric saccharide structures linked via covalent bonds to amino acids, peptides, proteins, lipids, and other structures. 

Structural Formula Not definitely known has a molecular weight of about 3,300, a nitrogen content of about 7% and a carbohydrate content of 16 to 17%. 

Lipids are naturally occurring organic molecules that have limited solubility in water and can be isolated from organisms by extraction with nonpolar organic solvents. Fats, oils, waxes, many vitamins and hormones, and most nonprotein cell-meznbrane components are examples. Note that this definition differs from the sort used for carbohydrates and proteins in that lipids are defined by a physical property (solubility) rather than by structure. Of the many kinds of lipids, we ll be concerned in this chapter only with a few triacvlglycerols, eicosanoids, terpenoids, and steroids. 

Carb-O. Historical development of carbohydrate nomenclature 0.1. Early approaches 0.2. The contribution of Emil Fischer 0.3. Cyclic forms 0.4. Nomenclature commissions 2-Carb-l. Definitions and conventions... 

The present Recommendations deal with the acyclic and cyclic forms of monosaccharides and their simple derivatives, as well as with the nomenclature of oligosaccharides and polysaccharides. They are additional to the Definitive Rules for the Nomenclature of Organic Chemistry [13,14] and are intended to govern those aspects of the nomenclature of carbohydrates not covered by those rules. 

Since the early 1970s a panel convened by the International Union of Pure and Applied Chemistry and the International Union of Biochemistry and Molecular Biology has been working to formulate recommendations for carbohydrate nomenclature that meet developing needs of research and electronic data handling, while retaining links to the established literature base on carbohydrates. The realization of these endeavors is presented here in the final document Nomenclature of Carbohydrates, which provides a definitive reference for current researchers, both in the text version and in the version accessible on the World Wide Web (http //www.chem.qmw.ac.uk/iupac/2carb/), where amendments and revisions are maintained. 

Sweetness is a quality that defies definition, but whose complexity can be appreciated merely by examining the molecular structures of those compounds that elicit the sensation. They come in all molecular shapes and sizes, and they belong to such seemingly unrelated classes of compounds as aliphatic and aromatic organic compounds, amino acids, peptides and proteins, carbohydrates, complex glycosides, and even certain inorganic salts. 

Dietary fibre, which comprises all the non-digestible structural carbohydrates of plant cell walls and any associate lignin, provides a further example of a complex food-borne factor which cannot be classified as a nutrient, and which continues to generate debate over such issues as definition and analytical techniques. However, whatever the unresolved complexities, dietary fibre has a lengthy history and had proved itself eminently suitable as a component of functional food products long before the term was even coined. 

Matrix Components The term matrix component refers to the constituents in the material aside from those being determined, which are denoted as analyte. Clearly, what is a matrix component to one analyst may be an analyte to another. Thus, in one hand for the case of analyses for elemental content, components such as dietary fibre, ash, protein, fat, and carbohydrate are classified as matrix components and are used to define the nature of the material. On the other hand, reference values are required to monitor the quality of determinations of these nutritionally significant matrix components. Hence, there is a challenging immediate need for certified values for dietary fibre, ash, protein, fat, and carbohydrate. Concomitantly, these values must be accompanied by scientifically sound definitions (e.g. total soluble dietary fibre, total sulpha-ted ash, total unsaturated fat, polyunsaturated fat, individual lipids, simple sugars, and complex carbohydrates). 

The most radical change of classification in this group is the abandonment of Levene s1 definition that the carbohydrate group of all... 

Carbohydrates are characterized by the presence of polyhydroxylic aldehyde or polyhydroxy-lic ketone structures or polymers made of such units. Sugars and polysaccharides have definite... 

The carbohydrate nomenclature jointly established by the American and British Committees4 does not specifically refer to the branched-chain sugars nevertheless, the application and extension of its Rules can provide definitive names to augment or to replace the trivial or unsystematic terms which have been conferred on naturally occurring, branched-chain sugars and related synthetic products, including the branched-chain saccharinic acids.6 9... 

The regulations prescribe the energy values to be used as in Table 3. There are agreed values for some other materials. The synthetic dextrose polymer poly dextrose is accepted to be only 1 kcal g 1 (or 4 kJ g 1) even though it would otherwise fall within the definition of a carbohydrate. The accepted value for gum acacia, a polysaccharide obtained from trees of the species Acacia Senegal and closely related species, is 2 kcal g 1 (or 8 kJ g-1). 

Average dissolved fractions of carbohydrates and proteins are shown in Table 3.4. Protein only exists in a dissolved form after transport in a sewer network, whereas lipids, per definition, are nondissolved. 

Alcohol consumption is very difficult to assess. There is widespread belief that individuals underreport their intake and there are no reliable laboratory tests available for definitive diagnosis of alcohol abuse. A combination of abnormalities in the plasma activity of gamma-glutamyl transferase (GGT or yGT), AST and reduction in erythrocyte mean cell volume (MCV) maybe useful and all are routine lab. tests. A potential marker of interest is carbohydrate-deficient transferrin (CDT) which is an abnormal isoform of serum transferrin arising due to defects in the attachment of carbohydrate chains to the protein core. Unfortunately, CDT is a somewhat specialized test, not performed by most laboratories. Other markers which have attracted some research interest are ethyl sulphate and ethyl glucuronide. Excretion in the urine of these metabolites occurs for up to 50 hours after binge drinking so they offer a useful index of recent heavy alcohol intake. 

Although a number of assays and technologies are available to characterize and test protein molecules, such as peptide mapping, protein sequencing, carbohydrate analysis, electrophoresis, ELISA, and mass spectroscopy, they are not as definitive as the methods used for small molecule drugs. Hence, the test for similarity is not as well defined in the case of proteins. However, as... 

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