Tragacanth

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Tragacanth

Tragacanth (also tragacanth , gum tragacanth , gum tragacanth , gum tragacanth ) is a rubber or a natural polysaccharide. It consists of the emerging after the scribing of trunks and branches and one drying vegetable juice of shrubby representatives of Schmetterlingsblütler genus of tragacanth ( Astragalus ) Astragalus gummifer , Astragalus bustillosii and Astragalus tragacanth , as well as Astracantha adscendens , Astracantha microcephala , Astracantha kurdica and Astracantha strobilifera which formerly belonged to the genus Astralagus .

Astragalus gummy and incised branch with excretions

The name traganth, from Latin tragacanthum , tragacantha , from Greek tragákantha , 'fenugreek', is composed of ancient Greek τράγος (trágos; billy goat ) and ἄκᾰνθος (ákanthos, Latin “acanthus” , “thorn flower”, from ákantha) , sting ; it refers to the thorny plants and the goat-horned rubber excrement.

A similar resin, karaya ( Indian tragacanth ), which is produced by species from the genus of stinky trees ( Sterculia spp. ), Is found, as well as kutira gum , which is secreted by representatives of the genus of snail -seed trees ( Cochlospermum spp. ), Often as Surrogate usage. False tragacanth or pseudotraganth also delivers z. B. Albizia adianthifolia and Moringa oleifera .

history

Traganth is already mentioned in the Bible (cf. Genesis 37:25 and 43:11).

construction

Tragacanth is rubbery. The rubbery mixture is made up of polysaccharides and esters and is used as an acid and heat-stable thickener in food. It consists of 60–70% tragacanthine (also tragacanthic acid or traganthin ) and 30–40% bassorin (also tragacanthic acid ). Tragacanthin is a water-soluble polysaccharide and consists of D - galacturonic acid and D - xylose in the main chain, and L - fucose and D - galactose in the side chains . The water-insoluble, but well swellable in water, Bassorin is composed of L - arabinose , D - galactose, L - rhamnose and the methyl ester of D - galacturonic acid.

Tragacanth is colorless to dark brown, translucent, odorless and tasteless, tough and difficult to pulverize. It appears in leaf-like, ribbon-like or sickle-shaped flat, only about 1 to 3 mm thick and at least 0.5 cm wide, often striped pieces (these are called maftuli ) or as oval and brittle flakes with a thickness of 10 to 50 mm (these are Called Kharmani ). Each variety is classified into multiple grades based on color, viscosity, and thickness. Large flakes and long ribbons of light color are the best varieties. Only one variety is usually produced per site.

Tragacanth comes mainly from Iran , Turkey, India and Afghanistan .

application

As a filler, stabilizer , thickener or gelling agent, it is z. B. salad dressings, bakery fillings and ice cream added. Decorative compounds such as flower and modeling pastes are added to give them the necessary elasticity.

It is used as a binding agent in watercolor painting .

In animal experiments , it was found to be problematic with regard to allergies .

It is approved in the EU as a food additive with the number E  413 without maximum quantity restriction ( quantum satis ) for food in general.

Tragacanth was also used in medicine. It has an immune stimulating and anti-inflammatory effect and also served as a filler and thickener.

Tragacanth was used to preserve the relic of the sacred skirt in 1890 . However, it turned brown and became brittle. In order to keep the fabric flexible, the humidity had to be increased, which led to a higher risk of mold.

literature

Individual evidence

  1. ↑ Helmut Genaust: Etymological dictionary of botanical plant names. Birkhäuser, 1976, ISBN 978-3-0348-7651-3 (reprint), p. 367.
  2. ↑ Alois Walde : Latin etymological dictionary. 3rd edition, obtained from Johann Baptist Hofmann , 3 volumes, Heidelberg 1938–1965, volume 2, p. 697.
  3. ↑ Amos Nussinovitch: Plant Gum Exudates of the World. CRC Press, 2010, ISBN 978-1-4200-5224-4 , p. 227.
  4. ^ EF Anthon: Concise dictionary of chemical-pharmaceutical, technical-chemical and pharmacognostic nomenclatures. Second edition, Schrag, 1861, p. 149.
  5. ↑ a b Entry on tragacanth. In: Römpp Online . Georg Thieme Verlag, accessed on February 22, 2013.
  6. ^ Robert Jaretzky: Textbook of Pharmacognosy. 2nd edition, Vieweg, 1949, ISBN 978-3-663-03153-6 , pp. 20 ff.
  7. ↑ Roy L. Whistler, James N. BeMiller: Industrial Gums: Polysaccharides and Their Derivatives. 3rd. Ed., Academic Press, New York, 1993, ISBN 978-0-12-746253-0 , pp. 289-99.
  8. ↑ Raymond E. Kirk, Donald F. Othmer: Kirk-Othmer Encyclopedia of Chemical Technology. Vol. XII, 4th. Ed., Wiley, New York, 1994, ISBN 978-0-471-52681-0 , p. 853.
  9. ^ Winfried Nerdinger: Elements of artistic design . Martin Lurz Verlag, Munich 1986, ISBN 3-87501-077-9 , p. 194 f .
  10. ↑ a b Additives database: tragacanth .
  11. ↑ Entry on E 413: Tragacanth in the European database on food additives, accessed on August 6, 2020.
  12. ↑ Eva Shenia Shemyakova: 'Des Juden buch von kreuczenach'. Investigation and edition of the recipe part of the Heidelberg Cpg 786. In: Fachproseforschung - Grenzüberreitungen. Volume 8/9, 2012/13, pp. 207–265, here: p. 225.
  13. ↑ A garment with many layers In: Trierischer Volksfreund . dated February 21, 2012.