Difference between revisions of "Karaya gum"

From CAMEO
Jump to navigation Jump to search
(username removed)
Line 1: Line 1:
 
== Description ==
 
== Description ==
  
A dried gummy exudate from ''Sterculia urens'' trees native to central and northern India. Karaya gum occurs as tears of variable size and of a somewhat crystalline appearance. The tears are a translucent, pale yellow, with a slightly acetic odor and a mucilaginous, slightly acetic taste. Karaya is a partially acetylated polysaccharide with about 8% acetic groups and 37% uronic acid residues that contains [http://cameo.mfa.org/materials/fullrecord.asp?name=rhamnose rhamnose], [http://cameo.mfa.org/materials/fullrecord.asp?name=galactose galactose], and galacturonic acid. It is acidic to [http://cameo.mfa.org/materials/fullrecord.asp?name=litmus litmus]. Karaya gum is insoluble in alcohol, but swells in water to form a [http://cameo.mfa.org/materials/fullrecord.asp?name=gel gel]. Gum karaya, which has only been available commercially since 1920, forms an extremely strong adhesive with small amounts of water. It is used as a medical adhesive, dye thickener, textile coating, emulsifier, and paper fiber binder.
+
A dried gummy exudate from ''Sterculia urens'' trees native to central and northern India. Karaya gum occurs as tears of variable size and of a somewhat crystalline appearance. The tears are a translucent, pale yellow, with a slightly acetic odor and a mucilaginous, slightly acetic taste. Karaya is a partially acetylated polysaccharide with about 8% acetic groups and 37% uronic acid residues that contains [[rhamnose]], [[galactose]], and galacturonic acid. It is acidic to [[litmus]]. Karaya gum is insoluble in alcohol, but swells in water to form a [[gel]]. Gum karaya, which has only been available commercially since 1920, forms an extremely strong adhesive with small amounts of water. It is used as a medical adhesive, dye thickener, textile coating, emulsifier, and paper fiber binder.
  
 
== Synonyms and Related Terms ==
 
== Synonyms and Related Terms ==

Revision as of 10:33, 21 January 2014

Description

A dried gummy exudate from Sterculia urens trees native to central and northern India. Karaya gum occurs as tears of variable size and of a somewhat crystalline appearance. The tears are a translucent, pale yellow, with a slightly acetic odor and a mucilaginous, slightly acetic taste. Karaya is a partially acetylated polysaccharide with about 8% acetic groups and 37% uronic acid residues that contains Rhamnose, Galactose, and galacturonic acid. It is acidic to Litmus. Karaya gum is insoluble in alcohol, but swells in water to form a Gel. Gum karaya, which has only been available commercially since 1920, forms an extremely strong adhesive with small amounts of water. It is used as a medical adhesive, dye thickener, textile coating, emulsifier, and paper fiber binder.

Synonyms and Related Terms

"gomme de karaya (Fr.); goma karaya (Esp.); kadaya gum; Indian tragacanth; Indian gum; bassora gum; kuteera gum; sterculia gum; gum hog; gum karaya; katilo; kulo; mucara "

Other Properties

Swells in cold water. Insoluble in ethanol.

CAS 9000-36-6

Authority

  • Richard S. Lewis, Hawley's Condensed Chemical Dictionary, Van Nostrand Reinhold, New York, 10th ed., 1993
  • Matt Roberts, Don Etherington, Bookbinding and the Conservation of Books: a Dictionary of Descriptive Terminology, U.S. Government Printing Office, Washington DC, 1982
  • Van Nostrand's Scientific Encyclopedia, Douglas M. Considine (ed.), Van Nostrand Reinhold, New York, 1976
  • John S. Mills, Raymond White, The Organic Chemistry of Museum Objects, Butterworth Heineman, London, 2nd ed., 1994
  • The Merck Index, Martha Windholz (ed.), Merck Research Labs, Rahway NJ, 10th edition, 1983 Comment: entry 5296

Retrieved from "https://cameo.mfa.org/index.php?title=Karaya_gum&oldid=45118"