Dextrin
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2008-07-11T09:27:58Z
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Fix typo.
'''Dextrins''' are a group of low-molecular-weight [[carbohydrate]]s produced by the [[hydrolysis]] of [[starch]]. Dextrins are mixtures of linear α-(1,4)-linked D-glucose polymers starting with an α-(1,6) bond. Because branched amylopectin and glycogen also contain α-(1,6) bonds, which α-amylase cannot hydrolyze in humans, the digest resulting from this action contains a mixture of dextrins. They have the same general [[formula]] as carbohydrates but are of shorter chain length. Industrial production is, in general, performed by acidic hydrolysis of potato starch. Dextrins are water-soluble, white to slightly yellow solids that are [[optical activity|optically active]]. Under analysis, dextrins can be detected with [[iodine]] solution, giving a red coloration.
[[Image:Dextrin.svg|thumb|right|Dextrin]]
The cyclical dextrins are known as [[cyclodextrin]]s. They are formed by [[enzyme|enzymatic]] degradation of starch by certain [[bacterium|bacteria]], for example, [[Diazotroph|Bacillus macerans]]. Cyclodextrins have toroidal structures formed by 6-8 [[glucose]] residues.
Dextrins find widespread use in industry, due to their non-[[toxicity]] and their low price. They are used as water-soluble [[glue]]s, as thickening agents in [[food processing]], and as binding agent in [[pharmaceutical]]s. In [[pyrotechnics]], they are added to fire formulas, allowing them to solidify as pellets or "stars." [[Cyclodextrin]]s find additional use in [[analytical chemistry]] as a matrix for the separation of [[hydrophobic]] substances, and as [[excipient]]s in pharmaceutical formulations. Not all forms of dextrin are digestible, and indigestible dextrin is sometimes used in [[Dietary fiber|fiber supplements]].
For example, '''maltodextrin''' either can be moderately [[sweet]] or have hardly any flavor at all. Maltodextrin is a [[polysaccharide]] that is used as a [[food additive]]. It is produced from [[starch]] and is usually found as a creamy-[[white]] [[hygroscopic]] powder. Maltodextrin is easily digestible, being absorbed as rapidly as [[glucose]]. The [[CAS registry number]] of maltodextrin is '''9050-36-6'''.
Maltodextrin can be derived from any starch. In the US, this starch is usually rice, corn or potato; elsewhere, such as in Europe, it is commonly wheat.
This is important for [[coeliac disease|coeliacs]], since the wheat-derived maltodextrin can contain traces of [[gluten]]. There have been recent reports of coeliac reaction to maltodextrin in the United States. This might be a consequence of the shift of corn to ethanol production and its replacement with wheat in the formulation. The fast food chain, Wendy's, footnotes maltodextrin in its list of gluten-free foods [http://www.wendys.com/food/pdf/us/gluten_free_list.pdf], which may be a sign of their receiving reports of this.
Foods containing maltodextrin may contain traces of [[amino acid]]s, including [[glutamic acid]] as a manufacturing by-product. The amino acid traces would be too small to have any dietary significance.
== See also ==
*[[Modified starch]]
*[[Starch gelatinization]]
*[[Dextran]]
==External links==
*[http://www.cfsan.fda.gov/~dms/eafus.html EAFUS]
*[http://www.grokfood.com/regulations/184.1444.htm Maltodextrin entry on Grokfood.com]
[[Category:Carbohydrates]]
[[Category:Polysaccharides]]
[[Category:Food additives]]
[[Category:Edible thickening agents]]
[[Category:Pyrotechnic chemicals]]
[[cs:Dextrin]]
[[de:Dextrine]]
[[es:Dextrina]]
[[fr:Dextrine]]
[[hr:Dekstrin]]
[[it:Destrina]]
[[ja:デキストリン]]
[[no:Dekstrin]]
[[pl:Dekstryny]]
[[pt:Dextrina]]
[[ru:Декстрин]]
[[uk:Декстрин]]
[[zh:糊精]]