Dextrins are a group of low-molecular-weight

carbohydrate In organic chemistry, a carbohydrate () is a biomolecule consisting of carbon (C), hydrogen (H) and oxygen (O) atoms, usually with a hydrogen–oxygen atom ratio of 2:1 (as in water) and thus with the empirical formula (where ''m'' may o ...

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, elimination, and solvation reactions in which water is the nucleophile. Biological hydrolysi ...

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 die ...

and

glycogen Glycogen is a multibranched polysaccharide of glucose that serves as a form of energy storage in animals, fungi, and bacteria. The polysaccharide structure represents the main storage form of glucose in the body. Glycogen functions as one of ...

. Dextrins are mixtures of

polymer A polymer (; Greek '' poly-'', "many" + '' -mer'', "part") is a substance or material consisting of very large molecules called macromolecules, composed of many repeating subunits. Due to their broad spectrum of properties, both synthetic a ...

s of D-

glucose Glucose is a simple sugar with the molecular formula . Glucose is overall the most abundant monosaccharide, a subcategory of carbohydrates. Glucose is mainly made by plants and most algae during photosynthesis from water and carbon dioxide, u ...

units linked by α-(1→4) or α-(1→6)

glycosidic bonds A glycosidic bond or glycosidic linkage is a type of covalent bond that joins a carbohydrate (sugar) molecule to another group, which may or may not be another carbohydrate. A glycosidic bond is formed between the hemiacetal or hemiketal gr ...

. Dextrins can be produced from starch using

enzyme Enzymes () are proteins that act as biological catalysts by accelerating chemical reactions. The molecules upon which enzymes may act are called substrates, and the enzyme converts the substrates into different molecules known as products ...

s like amylases, 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. The malt is mainly used for brewing or whisky making, but can also be used to make malt vinegar or malt extract. Various grains are used for malting, mo ...

and

mashing In brewing and distilling, mashing is the process of combining a mix of ground grains – typically malted barley with supplementary grains such as corn, sorghum, rye, or wheat – known as the " grain bill" with water and then heating the m ...

, or by applying dry heat under acidic conditions (

pyrolysis The pyrolysis (or devolatilization) process is the thermal decomposition of materials at elevated temperatures, often in an inert atmosphere. It involves a change of chemical composition. The word is coined from the Greek-derived elements '' ...

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 caramelizatio ...

). 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 staple food prepared from a dough of flour (usually wheat) and water, usually by baking. Throughout recorded history and around the world, it has been an important part of many cultures' diet. It is one of the oldest human-made f ...

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 The Maillard reaction ( ; ) is a chemical reaction between amino acids and reducing sugars that gives browned food its distinctive flavor. Seared steaks, fried dumplings, cookies and other kinds of biscuits, breads, toasted marshmallows, and m ...

. Dextrins are white, yellow, or brown powder that are partially or fully water-soluble, yielding

optically active Optical rotation, also known as polarization rotation or circular birefringence, is the rotation of the orientation of the plane of polarization about the optical axis of linearly polarized light as it travels through certain materials. Circul ...

solutions of low

viscosity The viscosity of a fluid is a measure of its resistance to deformation at a given rate. For liquids, it corresponds to the informal concept of "thickness": for example, syrup has a higher viscosity than water. Viscosity quantifies the int ...

. 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 advant ...

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 Green strength, or handling strength, can be defined as the strength of a material as it is processed to form its final ultimate tensile strength. This strength is usually considerably lower than the final ultimate strength of a material. The term ...

additives in

sand casting Sand casting, also known as sand molded casting, is a metal casting process characterized by using sand as the mold material. The term "sand casting" can also refer to an object produced via the sand casting process. Sand castings are produced ...

, as printing thickener for

batik Batik is an Indonesian technique of wax-resist dyeing applied to the whole cloth. This technique originated from the island of Java, Indonesia. Batik is made either by drawing dots and lines of the resist with a spouted tool called a ''ca ...

resist dyeing Resist dyeing (resist-dyeing) is a traditional method of dyeing textiles with patterns. Methods are used to " resist" or prevent the dye from reaching all the cloth, thereby creating a pattern and ground. The most common forms use wax, some typ ...

, and as binders in

gouache Gouache (; ), body color, or opaque watercolor is a water-medium paint consisting of natural pigment, water, a binding agent (usually gum arabic or dextrin), and sometimes additional inert material. Gouache is designed to be opaque. 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 includes many forms of processing foods, from grinding grain to make raw flour to home cooking to complex in ...

, in food batters, coatings, and glazes, ( INS number 1400) * a

textile finishing In textile manufacturing, finishing refers to the processes that convert the woven or knitted cloth into a usable material and more specifically to any process performed after dyeing the yarn or fabric to improve the look, performance, or "ha ...

and coating agent to increase weight and stiffness of textile fabrics * a thickening and binding agent in

pharmaceutical A medication (also called medicament, medicine, pharmaceutical drug, 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 medical field and ...

s and paper coatings * a pyrotechnic binder and fuel; this is added to

fireworks Fireworks are a class of low explosive pyrotechnic devices used for aesthetic and entertainment purposes. They are most commonly used in fireworks displays (also called a fireworks show or pyrotechnics), combining a large number of devices ...

and sparklers, allowing them to solidify as pellets or "stars" * a stabilizing agent for certain explosive metal azides, particularly Lead(II) azide Owing to their rebranching, dextrins are less digestible. Indigestible dextrins have been developed as soluble stand-alone

fiber supplement Fibre supplements (also spelled fiber supplements) are considered to be a form of a subgroup of functional dietary fibre, and in the United States are defined by the Institute of Medicine (IOM). According to the IOM, functional fibre "consists ...

s 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 Taste, flavor or enhance taste, appearance, or other sensory qualities. Some additives have been used for centuries as part of an effort to preserve food, for example vinegar (pickling), sal ...

. 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 hue). It is the color of objects such as snow, chalk, and milk, and is the opposite of black. White objects fully reflect and scatter all the visible wavelengths of light. White ...

hygroscopic Hygroscopy is the phenomenon of attracting and holding water molecules via either absorption or adsorption from the surrounding environment, which is usually at normal or room temperature. If water molecules become suspended among the substance' ...

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 (; singular: bacterium) are ubiquitous, mostly free-living organisms often consisting of one biological cell. They constitute a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria were am ...

, 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 20–30%. Because of its tightly packed helical structure, 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 amylopectin with beta amylase, 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