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Stairch or amylum is a carbohydrate consistin o a lairge nummer o glucose units jyned bi glycosidic bonds. This polysaccharide is produced bi maist green plants as energy storage. It is the maist common carbohydrate in human diets an is conteened in lairge amoonts in staple fuids lik tatties, wheat, maize (corn), rice, an cassava.

Stairch
Cornstairch bein mixed wi watter
Identifiers
ChemSpider
  • none
ECHA InfoCard 100.029.696
EC Nummer 232-679-6
RTECS nummer GM5090000
Properties
(C
6
H
10
O
5
)
n -
(H
2
O)
Molar mass Variable
Appearance White pouder
Density Variable[1]
Meltin pynt decomposes
insoluble (see starch gelatinization)
Thermochemistry
Std enthalpy o
combustion
ΔcHo298
4.1788 kilocalories per gram (17.484 kJ/g)[2] (Heicher heatin vailyie)
Hazards
Safety data sheet ICSC 1553
410 °C (770 °F; 683 K)
US heal exposur leemits (NIOSH):
PEL (Permissible)
TWA 15 mg/m3 (total) TWA 5 mg/m3 (resp)[3]
Except whaur itherwise notit, data are gien for materials in thair staundart state (at 25 °C [77 °F], 100 kPa).
YesY verify (whit is YesYN ?)
Infobox references

Pure stairch is a white, tasteless an odourless pouder that is insoluble in cauld watter or alcohol. It conseests o twa types o molecules: the linear an helical amylose an the branched amylopectin. Dependin on the plant, stairch generally conteens 20 tae 25% amylose an 75 tae 80% amylopectin bi wecht.[4] Glycogen, the glucose store o ainimals, is a mair heichly brainched version o amylopectin.

In industrie, stairch is convertit intae succars, for ensaumple bi mautin, an fermentit tae produce ethanol in the manufactur o beer, whisky an biofuel. It is processed tae produce mony o the succars used in processed fuids. Mixin maist stairches in wairm watter produces a paste, sic as wheatpaste, that can be uised as a thickenin, stiffenin or gluin agent. The biggest industrial non-fuid uise o stairch is as an adhesive in the papermakkin process. Staorch can be applee'd tae pairts o some garments afore airning, tae stiffen them.

ReferencesEedit

  1. Roy L. Whistler; James N. BeMiller; Eugene F. Paschall, eds. (2012). Starch: Chemistry and Technology. Academic Press. p. 220. Starch has variable density depending on botanical origin, prior treatment, and method of measurement 
  2. CRC Handbook of Chemistry and Physics, 49th edition, 1968-1969, p. D-188.
  3. NIOSH Pocket Guide tae Chemical Hazards 0567
  4. Brown, W. H.; Poon, T. (2005). Introduction to organic chemistry (3rd ed.). Wiley. ISBN 0-471-44451-0. [page needit]