Stairch

Stairch

Identifiers
CAS Nummer	9005-25-8 Y
ChemSpider	none
EC Nummer	232-679-6
RTECS nummer	GM5090000
Properties
Chemical formula	(C 6H 10O 5) n - (H 2O)
Molar mass	Variable
Appearance	White pouder
Density	Variable
Meltin pynt	decomposes
Solubility in watter	insoluble (see starch gelatinization)
Thermochemistry
Std enthalpy o combustion ΔcHo298	4.1788 kilocalories per gram (17.484 kJ/g) (Heicher heatin vailyie)
Hazards
Safety data sheet	ICSC 1553
Autoigneetion temperatur	410 °C (770 °F; 683 K)
US heal exposur leemits (NIOSH):
PEL (Permissible)	TWA 15 mg/m3 (total) TWA 5 mg/m3 (resp)
Except whaur itherwise notit, data are gien for materials in thair staundart state (at 25 °C [77 °F], 100 kPa).
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Infobox references

Stairch or amylum is a carbohydrate consistin o a muckle 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 muckle amoonts in staple fuids lik tatties, wheat, maize (corn), rice, an cassava.

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. 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.