Dextrin

Dextrin
Dextrin
Identifiers
CAS number 9004-53-9
UNII 2NX48Z0A9G YesY
KEGG C00721 YesY
Properties
Molecular formula (C6H10O5)n
Molar mass variable
Appearance white or yellow powder
 YesY (verify) (what is: YesY/N?)
Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)
Infobox references

Dextrins are a group of low-molecular-weight carbohydrates produced by the hydrolysis of starch[1] or glycogen.[2] Dextrins are mixtures of polymers of D-glucose units linked by α-(1→4) or α-(1→6) glycosidic bonds.

Dextrins can be produced from starch using enzymes like amylases, as during digestion in the human body and during malting and mashing,[3] or by applying dry heat under acidic conditions (pyrolysis or roasting). The latter process is used industrially, and also occurs on the surface of bread during the baking process, contributing to flavour, colour, and crispness. Dextrins produced by heat are also known as pyrodextrins. During roasting under acid condition the starch hydrolyses and short chained starch parts partially rebranche with α-(1,6) bonds to the degraded starch molecule.[4]

Dextrins are white, yellow, or brown powders that are partially or fully water-soluble, yielding optically active solutions of low viscosity. Most can be detected with iodine solution, giving a red coloration; one distinguishes erythrodextrin (dextrin that colours red) and achrodextrin (giving no colour).

White and yellow dextrins from starch roasted with little or no acid is called British gum.

A dextrin with α-(1→4) and α-(1→6) glycosidic bonds

Contents

Uses

Yellow dextrins are used as water-soluble glues [5] in remoistable envelope adhesives and paper tubes, in the mining industry as additives in froth flotation, in the foundry industry as green strength additives in sand casting, as printing thickener for batik resist dyeing, and as binders in gouache paint.

White dextrins are used as:

  • a crispness enhancer for food processing, in food batters, coatings, and glazes, (E number 1400)
  • a textile finishing and coating agent to increase weight and stiffness of textile fabrics
  • a thickening and binding agent in pharmaceuticals and paper coatings.

As pyrotechnic binder and fuel, they are added to fireworks and sparklers, allowing them to solidify as pellets or "stars."

Due to the rebranching, dextrins are less digestible; indigestible dextrin are developed as soluble fiber supplements for food products.

Other dextrin types

  • Maltodextrin
Main article: maltodextrin

Maltodextrin is a shortchain starch sugar, gelatin hybrid base, (dextrin) used as a food additive. It is produced also by enzymatic hydrolysis from gelatinated starch and is usually found as a creamy-white hygroscopic spraydried powder. Maltodextrin is easily digestible, being absorbed as rapidly as glucose, and might either be moderately sweet or have hardly any flavor at all.

  • Cyclodextrin
Main article: Cyclodextrin

The cyclical dextrins are known as cyclodextrins. They are formed by enzymatic degradation of starch by certain bacteria, for example, Bacillus macerans. Cyclodextrins have toroidal structures formed by 6-8 glucose residues.

  • Amylodextrin is a linear dextrin or short chained amylose (DP 20-30) that can be produced by enzymatic hydrolysis of the alpha-1,6 glycosidic bonds or debranching amylopectin. Amylodextrin colors blue with iodine.
  • (Beta) Limit dextrin is the remaining polymer produced by enzymatic hydrolysis of amylopectine with beta amylase, which cannot hydrolyse the alpha-1,6 bonds at branch points.
  • (Alpha) Limit dextrin is a short chained branched amylopectine remain, produced by hydrolysis of amylopectine with alpha amylase.
  • Highly branched cyclic dextrin is a dextrin produced from enzymatic breaking pf the amylopectin in clusters and using branching enzyme to form large cyclic chains.[6]

See also

Notes and references

  1. ^ An Introduction to the chemistry of plants - Vol II: Metabolic processes, P. Haas and T. G. Hill, London (Longmans, Green & Co.), 1913; pages 123-127
  2. ^ Salway, JG. Medical Biochemistry at a Glance. Second Edition. Malden, MA (Blackwell Publishing), 2006; page 66
  3. ^ Michael Lewis, Tom W. Young (2002), "Brewing"‎, Kluwer Academic, ISBN 0-306-47274-0.
  4. ^ Alistair M. Stephen, Glyn O. Phillips, Peter A. Williams (2006), "Food polysaccharides and their applications 2nd edition", p 92-99, CRC Press, Taylor & Francis Group, ISBN 0-8247-5922-2
  5. ^ Jack Augustus Radley (1976). "Industrial uses of starch and its derivatives‎", Applied Science Publishers Ltd, ISBN 0-85334-691-7.
  6. ^ T. Hiroki, K. Iwao, T. Noboru,S. Yuji, Y. Mikio, Journal: Seibutsu Kogakkaishi, Vol:84; No:2; Page: 61-66 (2006), Industrial Production of Branching Enzyme and Its Application to Production of Highly Branched Cyclic Dextrin (Cluster Dextrin)[1]

External links


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Look at other dictionaries:

  • Dextrin — (Stärke , Dampf oder Röstgummi, Gommelin, Leiokom oder Leiogomme, französ. Amidon grillé), ein in der Technik vielfach Verwendung findender Klebstoff von gummiartigen Eigenschaften, der aus Stärke hergestellt wird. In reinem Zustand stellt das… …   Lexikon der gesamten Technik

  • Dextrin — Dex trin, n. [Cf. F. dextrine, G. dextrin. See {Dexter}.] (Chem.) A translucent, gummy, amorphous substance, nearly tasteless and odorless, used as a substitute for gum, for sizing, etc., and obtained from starch by the action of heat, acids, or… …   The Collaborative International Dictionary of English

  • Dextrīn — (Stärkegummi, künstliches Gummi, Dampfgummi) C6H10O5, ein zur Gruppe der Kohlehydrate gehören der Körper von gleicher prozentischer Zusammensetzung mit Stärkemehl, Holzfaser (Zellulose) und Zucker, findet sich sehr verbreitet im Pflanzenreich,… …   Meyers Großes Konversations-Lexikon

  • Dextrīn — (Stärkegummi, Leiocome, Leiocomme, Gommaline, Chem.), C12H10O10, eine dem arabischen Gummi ähnliche Gummiart; entsteht durch Einwirkung von Wärme, verdünnten Säuren, Diastase u. verschiedenen thierischen Flüssigkeiten auf Stärkemehl; bildet eine… …   Pierer's Universal-Lexikon

  • Dextrin — Dextrīn, Stärkegummi, entsteht aus dem Stärkemehl durch Erhitzen desselben für sich (bis 160°) oder mit verdünnten Säuren oder mit Diastase (neben Malzzucker), fast farblose, gummiartige Stücke oder gelbliches bis braunes Pulver, löslich in… …   Kleines Konversations-Lexikon

  • Dextrin — Dextrin, Leiocome, das Stärkegummi, ein durch den Einfluß der Agentien verändertes Stärkemehl; die Agentien sind: Wärme, Säuren und die sog. Diastase. Gegenwärtig in dreierlei Formen im Handel: am seltensten in Gestalt kleiner durchsichtiger… …   Herders Conversations-Lexikon

  • dextrin — [deks′trēn΄, deks′trindeks′trin] n. [Fr dextrine (see DEXTER & IN1): so called because it rotates the plane of polarization to the right] any of a number of water soluble, gummy, dextrorotatory polysaccharides obtained from the breakdown of… …   English World dictionary

  • Dextrin — Struktur von Dextrin Dextrine, auch Stärkegummi genannt, sind Poly und Oligosaccharidgemische und liegen üblicherweise in Form von weißem bzw. hellgelbem Pulver vor. Sie werden hauptsächlich aus Weizen und Maisstärke durch trockene Erhitzung… …   Deutsch Wikipedia

  • dextrin — A mixture of oligo(α 1,4 d glucose) molecules formed during the enzymic or acid hydrolysis of starch, amylopectin, or glycogen; on further hydrolysis they are converted into d glucose. Dextrins are of much lower molecular weight than dextrans,… …   Medical dictionary

  • dextrin — n. a carbohydrate formed as an intermediate product in the digestion of starch by the enzyme amylase. Dextrin is used in the preparation of pharmaceutical products (as an excipient) and surgical dressings …   The new mediacal dictionary

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