Dextrins are a group of low-molecular-weight

carbohydrate A carbohydrate () is a biomolecule composed of carbon (C), hydrogen (H), and oxygen (O) atoms. The typical hydrogen-to-oxygen atomic ratio is 2:1, analogous to that of water, and is represented by the empirical formula (where ''m'' and ''n'' ...

s produced by the

hydrolysis Hydrolysis (; ) is any chemical reaction in which a molecule of water breaks one or more chemical bonds. The term is used broadly for substitution reaction, substitution, elimination reaction, elimination, and solvation reactions in which water ...

starch Starch or amylum is a polymeric carbohydrate consisting of numerous glucose units joined by glycosidic bonds. This polysaccharide is produced by most green plants for energy storage. Worldwide, it is the most common carbohydrate in human diet ...

and

glycogen Glycogen is a multibranched polysaccharide of glucose that serves as a form of energy storage in animals, fungi, and bacteria. It is the main storage form of glucose in the human body. Glycogen functions as one of three regularly used forms ...

. Dextrins are mixtures of

polymer A polymer () is a chemical substance, substance or material that consists of very large molecules, or macromolecules, that are constituted by many repeat unit, repeating subunits derived from one or more species of monomers. Due to their br ...

s of D-

glucose Glucose is a sugar with the Chemical formula#Molecular formula, molecular formula , which is often abbreviated as Glc. It is overall the most abundant monosaccharide, a subcategory of carbohydrates. It is mainly made by plants and most algae d ...

units linked by α-(1→4) or α-(1→6) glycosidic bonds. Dextrins can be produced from starch using

enzyme An enzyme () is a protein that acts as a biological catalyst by accelerating chemical reactions. The molecules upon which enzymes may act are called substrate (chemistry), substrates, and the enzyme converts the substrates into different mol ...

s like

amylase An amylase () is an enzyme that catalysis, catalyses the hydrolysis of starch (Latin ') into sugars. Amylase is present in the saliva of humans and some other mammals, where it begins the chemical process of digestion. Foods that contain large ...

s, as during digestion in the human body and during

malting Malting is the process of steeping, germinating, and drying grain to convert it into malt. Germination and sprouting involve a number of enzymes to produce the changes from seed to seedling and the malt producer stops this stage of the process w ...

and

mashing In brewing and distilling, mashing is the process of combining ground grain – malted barley and sometimes supplementary grains such as corn, sorghum, rye, or wheat (known as the " grain bill") – with water and then heating the mixture. Ma ...

in beer brewing or by applying dry heat under acidic conditions (

pyrolysis Pyrolysis is a process involving the Bond cleavage, separation of covalent bonds in organic matter by thermal decomposition within an Chemically inert, inert environment without oxygen. Etymology The word ''pyrolysis'' is coined from the Gree ...

roasting Roasting is a cooking method that uses dry heat where hot air covers the food, cooking it evenly on all sides with temperatures of at least from an open flame, oven, or other heat source. Roasting can enhance the flavor through caramelizat ...

). This procedure was first discovered in 1811 by Edme-Jean Baptiste Bouillon-Lagrange. The latter process is used industrially, and also occurs on the surface of

bread Bread is a baked food product made from water, flour, and often yeast. It is a staple food across the world, particularly in Europe and the Middle East. Throughout recorded history and around the world, it has been an important part of many cu ...

during the baking process, contributing to flavor, color and crispness. Dextrins produced by heat are also known as pyrodextrins. Starch hydrolyses during roasting under acidic conditions, and short-chained starch parts partially rebranch with α-(1,6) bonds to the degraded starch molecule. See also Maillard reaction. Dextrins are white, yellow, or brown powders that are partially or fully water-soluble, yielding optically active solutions of low

viscosity Viscosity is a measure of a fluid's rate-dependent drag (physics), resistance to a change in shape or to movement of its neighboring portions relative to one another. For liquids, it corresponds to the informal concept of ''thickness''; for e ...

. Most of them 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 are called British gum. Dextrin skeletal

Uses

Yellow dextrins are used as water-soluble

glue Adhesive, also known as glue, cement, mucilage, or paste, is any non-metallic substance applied to one or both surfaces of two separate items that binds them together and resists their separation. The use of adhesives offers certain advantage ...

s in remoistenable envelope adhesives and paper tubes, in the mining industry as additives in froth flotation, in the

foundry A foundry is a factory that produces metal castings. Metals are cast into shapes by melting them into a liquid, pouring the metal into a mold, and removing the mold material after the metal has solidified as it cools. The most common metals pr ...

industry as green strength additives in sand casting, as printing thickener for

batik Batik is a dyeing technique using wax Resist dyeing, resist. The term is also used to describe patterned textiles created with that technique. Batik is made by drawing or stamping wax on a cloth to prevent colour absorption during the dyein ...

resist dyeing, and as binders in gouache paint and also in the leather industry. White dextrins are used as: * A crispness enhancer for

food processing Food processing is the transformation of agricultural products into food, or of one form of food into other forms. Food processing takes many forms, from grinding grain into raw flour, home cooking, and complex industrial methods used in the mak ...

, in food batters, coatings, and glazes, ( INS number 1400) * a textile finishing and coating agent to increase weight and stiffness of textile fabrics * a thickening and binding agent in

pharmaceutical Medication (also called medicament, medicine, pharmaceutical drug, medicinal product, medicinal drug or simply drug) is a drug used to diagnose, cure, treat, or prevent disease. Drug therapy ( pharmacotherapy) is an important part of the ...

s and paper coatings * a pyrotechnic binder and fuel; this is added to firework effect or color compositions; allowing them to solidify as pellets (stars or comets); and to

sparkler A sparkler is a type of hand-held firework that burns slowly while emitting bright, colored sparks. It burns in high temperature (over 1000°C), so it can be very dangerous. Sparklers are particularly popular with children. In the United ...

compositions which the handle is dipped in * a stabilizing agent for certain explosive metal azides, particularly Lead(II) azide Owing to their rebranching, dextrins are less digestible than other carbohydrates. Indigestible dextrins have been developed as soluble stand-alone fiber supplements and for adding to processed food products.

Other types

* Maltodextrin Maltodextrin is a short-chain

sugar used as a

food additive Food additives are substances added to food to preserve flavor or enhance taste, appearance, or other sensory qualities. Some additives, such as vinegar ( pickling), salt ( salting), smoke ( smoking) and sugar ( crystallization), have been used f ...

. It is also produced by enzymatic hydrolysis from gelled starch, and is usually found as a creamy-

white White is the lightest color and is achromatic (having no chroma). It is the color of objects such as snow, chalk, and milk, and is the opposite of black. White objects fully (or almost fully) reflect and scatter all the visible wa ...

hygroscopic Hygroscopy is the phenomenon of attracting and holding water molecules via either absorption (chemistry), absorption or adsorption from the surrounding Natural environment, environment, which is usually at normal or room temperature. If water mol ...

spray-dried powder. Maltodextrin is easily digestible, being absorbed as rapidly as

, and might either be moderately sweet or have hardly any flavor at all. * Cyclodextrin The cyclical dextrins are known as cyclodextrins. They are formed by enzymatic degradation of starch by certain

bacteria Bacteria (; : bacterium) are ubiquitous, mostly free-living organisms often consisting of one Cell (biology), biological cell. They constitute a large domain (biology), domain of Prokaryote, prokaryotic microorganisms. Typically a few micr ...

, for example, '' Paenibacillus macerans'' (''Bacillus macerans''). Cyclodextrins have toroidal structures formed by 6–8

residues. * Amylodextrin is a linear dextrin or short chained

amylose Amylose is a polysaccharide made of α-D-glucose units, bonded to each other through α(1→4) glycosidic bonds. It is one of the two components of starch, making up approximately 20–25% of it. Because of its tightly packed Helix, helical struct ...

( 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

amylopectin Amylopectin is a water-insoluble polysaccharide and highly branched polymer of α-glucose units found in plants. It is one of the two components of starch, the other being amylose. Plants store starch within specialized organelles called amyloplas ...

with beta

, which cannot hydrolyse the alpha-1,6 bonds at branch points. *(Alpha) Limit dextrin is a short chained branched amylopectin remnant, produced by hydrolysis of amylopectin with alpha amylase. * Highly branched cyclic dextrin is a dextrin produced from enzymatic breaking of the amylopectin in clusters and using branching enzyme to form large cyclic chains.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 Dextri

References

External links

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EAFUS
{{Authority control Edible thickening agents Food additives Polysaccharides Pyrotechnic chemicals Starch