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Starch

Starch is a polysaccharide of amylose and amylopectin. It is tasteless, amorphous white powder, insoluble in cold water. Under the microscope it is a granular powder, while compressing powder starch in hand, it produces a characteristic "squeak", caused by the friction of the particles. In hot water it swells (dissolved), forming a colloidal solution - the paste. In water, with the addition of acid (H2SO4 diluted, etc.) as a catalyst, starch is gradually hydrolyzed with decreasing molecular weight down to glucose.

Starch is the main reserve substance of most plants. It is formed in the cells of green parts of plants and accumulated in seeds, tubers, bulbs, etc. Potatoes contain up to 24% of starch.

Molecules of starch are of two types: linear - amylose and branched - amylopectin. The molecules of amylose and amylopectin are joined together through hydrogen bonds, forming a radial layers and forming granules of starch.

Starches from different sources vary in size and shape of granules, the ratio of amylose / amylopectin and molecular structure of amylose and amylopectin.

Amylose makes a major contribution to the strength of gels, whereas the content of amylopectin depends on the viscosity. Thus, starch with high amylose exhibits gelling properties, and starch, consisting essentially of amylopectin, demonstrates a high viscosity.
The size of granules of different starches are in the range from 3 to 100 microns. Grain size by itself has little influence on the properties of starch. Although, in most cases, sizable granules swell easier.

The form of granules may be different, they can be spherical and oval, lenticular, irregular, have a smooth surface or the type of polyhedron, etc.

Starch is mostly made from
potato, corn, wheat, tapioca and rice.

Starch, which is produced directly from potatoes, is a rather expensive product, so the potato starch is often derived from so called “starched” water after waterjet in the production of potato crisps, potato flakes and fried potato. The production of such starch is much cheaper and its quality is not lower, than the starch, produced from starch potatoes.

One of the leading companies in production and processing of potato starch as a byproduct is a Dutch company Novidon BV. Production sites are located in Nijmegen (Netherlands), in Wrexham (UK) and Veurne (Belgium).

Novidon BV uses only the raw materials of exceptionally high quality. The company has its own professional laboratory, where the incoming raw materials and final starch products are constantly checked for compliance with ISO and other standards.

Potato starch can be native (natural) and modified. Modified starch - a change of one or more properties of native starch.

While the area of use of native starch is limited (basically, it is used in food industry), the scope of the modified starch is much greater: in addition to food, modified starches used in paper industry, production of adhesives and petroleum industries. 


Literature:

www.novidon-starch.com

wikipedia.org

www.nprb.ru

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