Sugars that contain free OH group at the anomeric carbon atom
Reducing form of glucose (the aldehyde group is on the far right)
A reducing sugar is any sugar that is capable of acting as a reducing agent.[1] In an alkaline solution, a reducing sugar forms some aldehyde or ketone, which allows it to act as a reducing agent, for example in Benedict's reagent. In such a reaction, the sugar becomes a carboxylic acid.
All monosaccharides are reducing sugars, along with some disaccharides, some oligosaccharides, and some polysaccharides. The monosaccharides can be divided into two groups: the aldoses, which have an aldehyde group, and the ketoses, which have a ketone group. Ketoses must first tautomerize to aldoses before they can act as reducing sugars. The common dietary monosaccharides galactose, glucose and fructose are all reducing sugars.
Disaccharides are formed from two monosaccharides and can be classified as either reducing or nonreducing. Nonreducing disaccharides like sucrose and trehalose have glycosidic bonds between their anomeric carbons and thus cannot convert to an open-chain form with an aldehyde group; they are stuck in the cyclic form. Reducing disaccharides like lactose and maltose have only one of their two anomeric carbons involved in the glycosidic bond, while the other is free and can convert to an open-chain form with an aldehyde group.
The aldehyde functional group allows the sugar to act as a reducing agent, for example, in the Tollens' test or Benedict's test. The cyclic hemiacetal forms of aldoses can open to reveal an aldehyde, and certain ketoses can undergo tautomerization to become aldoses. However, acetals, including those found in polysaccharide linkages, cannot easily become free aldehydes.
Reducing sugars react with amino acids in the Maillard reaction, a series of reactions that occurs while cooking food at high temperatures and that is important in determining the flavor of food. Also, the levels of reducing sugars in wine, juice, and sugarcane are indicative of the quality of these food products.
^Pratt, Charlotte W.; Cornely, Kathleen (2013). Essential Biochemistry (Third ed.). Wiley. p. 626. ISBN 978-1118083505.
A reducingsugar is any sugar that is capable of acting as a reducing agent. In an alkaline solution, a reducingsugar forms some aldehyde or ketone, which...
glucose and other reducingsugars do. Since sucrose contains no anomeric hydroxyl groups, it is classified as a non-reducingsugar. Sucrose crystallizes...
seeds, which is why it was named after malt. Unlike sucrose, it is a reducingsugar. Maltose was discovered by Augustin-Pierre Dubrunfaut, although this...
Reducing disaccharides, in which one monosaccharide, the reducingsugar of the pair, still has a free hemiacetal unit that can perform as a reducing aldehyde...
Sugar is the generic name for sweet-tasting, soluble carbohydrates, many of which are used in food. Simple sugars, also called monosaccharides, include...
In chemistry, a reducing agent (also known as a reductant, reducer, or electron donor) is a chemical species that "donates" an electron to an electron...
The sugar industry subsumes the production, processing and marketing of sugars (mostly sucrose and fructose). Globally, most sugar is extracted from sugar...
Monosaccharides (from Greek monos: single, sacchar: sugar), also called simple sugars, are the simplest forms of sugar and the most basic units (monomers) from which...
biomass. Like most sugars, it can adopt several structures depending on conditions. With its free aldehyde group, it is a reducingsugar. The acyclic form...
Glucose is a sugar with the molecular formula C6H12O6. Glucose is overall the most abundant monosaccharide, a subcategory of carbohydrates. Glucose is...
for reducing polysaccharides or disaccharides Benedict's reagent tests for reducingsugars or aldehydes Fehling's solution tests for reducingsugars or...
Dextrose equivalent (DE) is a measure of the amount of reducingsugars present in a sugar product, expressed as a percentage on a dry basis relative to...
A sugar substitute is a food additive that provides a sweetness like that of sugar while containing significantly less food energy than sugar-based sweeteners...
Lustig came to public attention in 2009 when one of his medical lectures, "Sugar: The Bitter Truth", was aired. He is the editor of Obesity Before Birth:...
lactation, and diabetes as the villi hypertrophy. Sucrose is a non-reducingsugar, so will not test positive with Benedict's solution. To test for sucrose...
the α-(1-4)-linkage. Both of the sugars are dimers of glucose, which is a pyranose sugar. Isomaltose is a reducingsugar. Isomaltose is produced when high...
(C6H7(OH)4O)2O. It is classified as a reducingsugar - any sugar that possesses the ability or function of a reducing agent. The chemical structure of cellobiose...
calories. They are marketed for diabetics and other people who want to reduce their sugar and/or caloric intake. Though artificial sweeteners had been known...
my-YAR; French: [majaʁ]) is a chemical reaction between amino acids and reducingsugars to create melanoidins, the compounds which give browned food its distinctive...
they stated that their results can be taken as a confirm that "reducing the amount of sugar in our diet is extremely important." Dental caries, also known...
Maillard reaction, a non-enzymatic reaction of an amino group with a reducingsugar. The volatile compounds produced from this reaction give miso its characteristic...
chemically reduced through the action of sodium borohydride to produce their corresponding sugar alcohols. These compounds do not react in reducingsugar assays...
isomaltulose is a reducingsugar. Isomaltulose is hydrogenated to produce isomalt, a minimally digestible carbohydrate that is used as a sugar replacer, for...
powder for mixing with water. An artificially sweetened version with reducedsugar called Pocari Sweat Ion Water (ポカリスエット イオンウォーター, Pokari Suetto Ion Wōtā)...
degradation (caramelization) of sugars. Isomaltol is obtained after the Maillard reaction from an amino acid and a reducingsugar[citation needed] Maltol Merck...
achiral meso four-carbon sugar alcohol (or polyol). It is the reduced form of either D- or L-erythrose and one of the two reduced forms of erythrulose. It...
Brown sugar is a sucrose sugar product with a distinctive brown color due to the presence of molasses. It is by tradition an unrefined or partially refined...
Global Information