Packaging and storage—
Preserve in well-closed containers.
Botanic characteristics—
Tragacanth—
Flattened, lamellated, frequently curved fragments or straight or spirally twisted linear pieces from 0.5 mm to 2.5 mm in thickness. Is white to weak yellow in color, translucent, and horny in texture. Its fracture is short. Is rendered more easily pulverizable by heating to 50
. Is odorless.
Histology—
Pieces of Tragacanth softened in water and mounted in water or glycerin show numerous lamellae and a few starch grains.
Powdered Tragacanth—
White to yellowish white. When examined in water mounts, it shows numerous angular fragments of mucilage with circular or irregular lamellae, and occasional starch grains up to 25 µm in diameter, mostly simple, spherical to elliptical, with occasional 2- to 4-compound grains, a few of the grains being swollen and more or less altered. The powder shows few or no fragments of lignified vegetable tissue (Indian gum).
Identification—
Add 1 g to 50 mL of water: it swells and forms a smooth, nearly uniform, stiff, opalescent mucilage free from cellular fragments.
Microbial limits 
61
—
It meets the requirements of the tests for absence of
Salmonella species and
Escherichia coli .
Karaya gum—
Boil 1 g with 20 mL of water until a mucilage is formed, add 5 mL of hydrochloric acid, and again boil the mixture for 5 minutes: no pink or red color develops.
