1. Structure of cassava tubers - Cassava is a tuber with a core (heart tubers) connection from trunk to tail along the tubers and roots. - Components: wood chips, bark pulp, meat cassava, cassava core. Compared with other root vegetables cassava bark is distinctive types of shells and most easily separated.
+) Shell wood Accounting for 0.5 to 3% by weight of tubers. Consists of cells which are composed of cellulose and hemicellulose, almost no starch. Crust is the outermost layer of wood, rough, dark brown, containing specific pigments. Keep the bulbs work very durable, without external mechanical action.
+) Shell stubs Thicker wood chips, about 8-20% by weight of tubers. Including cell is composed of cellulose and starch (5-8%). Between the crust is plastic pipe network tubers, the pus are more tannins, enzymes and pigments
+) Meat cassava (tubers intestine)
Who comprise mainly of tubers, including cells which are composed of cellulose and pentozan, inside the starch granules and cytoplasm. Starch content in tubers gut unevenly distributed. Kong starch grain size 15-80mm. Manioc as to older, the more fiber.
+) Core tapioca
Often located in the center along the tubers, roots linking itself to tail. The core occupies from 0.3 to 1% by weight of tubers. The constituents are mainly cellulose and hemicelluloses.
cassava starch
2. Chemical properties Fresh cassava roots: - The percentage of 38-40% dry matter, - 16-32% starch; - The quality of protein, fat, fiber, ash in 100g are respectively 0,8-2,5g, 0,2-0,3g, 1,1-1,7g, 0,6-0,9g; - The quality of minerals and vitamins is 18,8-22,5mg Ca 100g tubers, 22,5-25,4mg P, 0.02 mg B1, B2 0.02 mg, 0.5 mg PP.
In tubers, concentrations of amino acids are not balanced, redundant arginine but lacks the sulfur-containing amino acid. Like the majority of grains and tubers, the main component of starch cassava roots. In addition, the tapioca also substances: protein, minerals, lipids, fiber and some vitamins B1, B2.
Starch As an important component of cassava roots, it decided to use our values. Starch granules drums, diameter 35 mircomet. Starch consists of two components: - Amylose: 15-25%. - Amylopectin: 75-85%.
Amylopectin ratio: Tapioca starch Amylo in high (80:20), the starch gel viscosity, high adhesion and ability to gel a low degraded. Cassava Starch content is most concentrated at the close casings, deeper into the meat layers close to the core of starch less. Starch is a sphere, ovoid or shaped hat, there are some low-lying county, with very white color. Should the manufacturing process should eliminate dark shell to not create starch.
Amylopectin ratio: Tapioca starch Amylo in high (80:20), the starch gel viscosity, high adhesion and ability to gel a low degraded. Cassava Starch content is most concentrated at the close casings, deeper into the meat layers close to the core of starch less. HinTinh form starch tapioca in size from 5 to 40μm with 25-35μm large particles, small particles 5-15μm and the shape, mostly round, smooth surface, one side has shaped recess hats and a small knob in the middle. Under polarized light, the cross-linking density from medium to thick can be clearly seen. Ultrastructural studies using X-rays showed tapioca starch crystal structure and form a mixture A, B.h bridges, ovoid or shaped hat, there are some low-lying county, with very white color. Should the manufacturing process should eliminate dark shell to not create starch.
When tapioca starch granules burst, can observe the grooves porous structure of the particle. The amorphous slot extending from the surface of the particle to create heart
Vietnamese
English
