| advertise add site services publishers database health videos | ![]() | about toolbar stats live show health store more stuff JOIN/LOGIN |
Dextrins are a group of low-molecular-weight carbohydrates produced by the hydrolysis of starch. Dextrins are mixtures of polymers of D-glucose units linked by α-(1,4) or α-(1,6) bonds glycosidic bonds. Dextrins can be produced from starch using enzymes like amylases, as during digestion in the human body and during malting and mashing, 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 rebranches with α-(1,6) bonds to the degraded starch molecule. 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.
[edit] UsesYellow dextrins are used as water-soluble glues 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, and as binders in gouache paint. White dextrins are used as:
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. [edit] Other dextrin types
Main article: maltodextrin Maltodextrin is a short chained starch sugar, gelatin hybrid base, (dextrin), that is 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 might have hardly any flavor at all.
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.
[edit] See also[edit] References[edit] External links
| |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| ↑ top of page ↑ | about thumbshots |