Exudate gums karaya

Gum Karaya. Gum karaya [19000-36-61] or sterculia gum is the dried exudate of the Sterculia urens tree, which is now cultivated in India, the primary producing area. The best quahty gum is collected by tapping the trees during the period April to June with a second collection of lower quahty product later in the year. The gum is allowed to dry on the trees, and the cmde gum is collected and sorted according to color and purity. It is further sorted and processed to powdered gum karaya in the country of use. The quahty of supphes varies greatly (43). 

Natural gums include plant exudates, seed gums, plant extracts, seaweed extracts, and the extracellular microbial polysaccharides. Plant exudates include gum arabic, gum ghatti, gum karaya, and gum tragacanth. Seed gums include... 

Plant exudates Gum Arabic Adraganta gum Karaya gum Gatti gum... 

There are other exudate gums that were gums of commerce in ancient times and used up to about World War 11 that are used in only very small amounts today. They are gum karaya, gum ghatti, and gum tragacanth [64,65,66,67]. 

Gum Karaya (also known as Sterculia gum) is a dried exudate. ... 

Powdered gum karaya is white to grayish white and one of the least soluble of the exudate gums (only 10% of the native gum solubilizes in cold water, increasing to 30% in hot water. After deacetylation, 90% dissolves in water. ... 

Several naturally occurring anionic polysaccharides exist alginic acid, pectin, carrageenans, xanthan gum, hyaluronic acidic, gum exudates (gum arabic, karaya, traganth, etc.). Cross-linking sites that occur when a polyvalent cation (e.g. Ca +) causes interpolysaccharide binding are called "junction zones . 

Gum karaya is the dried exudation of Sterculia spp., especially Sterculia mens, and is sometimes known as Sterculia gum. Of the exudate gums, it ranks second to gum arabic in commercial utilization. 

All gum karaya comes from India, where the trees are cultivated and production is closely supervised. Holes about 10 cm deep are drilled into the trunks of the trees. After the slowly exuding gum has hardened, it is collected by hand, and pieces are sorted and graded. The best grades are white and contain a minimum of extraneous matter. Lower grades are light yellow to brown in color and may contain up to 3% of impurities, such as bark and sand (16, 20). 

This has prompted research activities all over the world to find alternative feedstocks for polymers. Agricultural by-products and forest products have become more attractive these days as renewable resources for polymers and plastics additives. Plant exudates such as gum arable, gum ghatti, gum karaya, gum tragacanth etc. have been used in textiles, cosmetics and pharmaceuticals mainly as emulsifiers and thicknersl. Other types of gums from seed such as guar gum have similarly been used. But these have not been utilized as the raw material for polymer manufacture. 

Gum karaya (sometimes referred to as StercuHa gum) is a bark exudate of trees of the genus StercuHa (StercuHaceae), mainly of S. urens, growing on the plateaus of central and northern India. Similar properties are found in some other species of the genus Ster-cuHa, for example S. setigera, S. caudata and S. villosa or some species of the genus Cochlospermum of the Cochlospermaceae family. 

Karaya Gum Vko- ri-o-I [Hindi kardyal resin] (1916) Dry exudation from Sterculia mens, which grows in India. It swells in water, and has some resemblance to gum tragacanth. (Industrial gums Polysaccharides and their derivatives. Whistler JN, BeMiller JN (eds). Elsevier Science and Technology Books, 1992) Also known as Gum Karaya. 

Gum karaya is the dried exudation from the trunk of Sterculia urens, which is a soft-wooded tree with an erect trunk and broad top, up to 9 m high. Leaves are ca. 20-30cm diameter, crowded at the end of branches, palmately lobed, glabrous above, velvety beneath, and flowers, numerous, yellow, small ca. 6-9 mm in diameter. It is native to India and is cultivated there for gum karaya production. 

Gum karaya is the least soluble of the commercial plant exudates, but it absorbs water rapidly and swells to form viscous... 

A wide variety of plant exudates have been used ia foods and medicines for centuries, including acacia, karaya, and ghatti. Plant gums derived from seeds iaclude arabic, guar, locust bean, tamatind, and tara. AH play a role ia fat replacement either singly or ia mixtures. 

Although many plant gum exudates are known (37,38), only gum arable, ghatti, karaya, and tragacanth have wide industrial use. 

Natural Plant Tree and shrub exudates Karaya gum Tragacanth gum Gum acacia... 

This type is principally composed of gums, which are complex carbohydrates of the sugar group. They occur as exudations of hardened sap on the bark of various tropical species of trees. All are strongly hydrophilic. Examples are arabic. tragacanth, karaya. 

S. urens (.5,39) Karaya gum, Indian tragacanth North and central India Occasionally sold as kutira often exudes immediately upon incision of any part of tree, including the leaves (43). 

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