Alginate

The alginates are Polysaccharide S obtained starting from a family of Brown algas: laminar .

They can form hard gel and Thermostable S used like Food additive (E400 with E405) allowing the rebuilding of the food (ham, cordon-bleu cooks, the breaded fish…). The alginates give a consistent texture to number of food such as the ice creams. The alkaline alginates form in the water of the viscous colloidal solutions while the calcium alginate is insoluble like the alginic acid itself. The alginates are used as thickeners, gelling, emulsifying and stabilizing industrial products the most varied since the food frosts, the beauty products, until paintings and with the printing inks. Gelled milks are it by alginates and Carraghénane S, which produces pasteurized lacteous desserts.

Alginate balls can also be used in medicine to encapsulate fragile drugs or biological substances (enzymes, micro-organisms, animal or human cells). The propane-1,2-diol alginate (E405), ester of the acid aliginic, is used, for example, to produce of foam (wine making, beer additive…).
The alginate is also used to carry out mouldings on the human body thanks to its hypoallergenic qualities. It is often the product used by the dentists for the dental catches of impressed. Its color varies cream-coloured white with the dark ivory. Its very fine Granulométrie allows very faithful prints.

It is also used by the specialists in the special Effets with the cinema to reproduce parts of the human body.

The alginic Acide was discovered by E.C. Stanford, a British pharmacist in the Années 1880. It is drawn from the algae and allows the production of calcium and sodium alginate fibers. The Alginate sodium is very water soluble, the alginate of calcium is only soluble in basic medium, in particular in soap solutions which are almost always rather alkaline: from where the use of these fibers like momentary supports, which will be to eliminate after manufacture, by washing or fulling. To transform the articles into insoluble alginates, one uses them in the form of salts of Béryllium or Chrome.

Chemical composition

The alginate is a formed polymer of two monomers bound together: the acid mannuronate or mannuronic and the guluronate or Acid guluronic. The proportion and the distribution of these two monomers are determining for a broad expansion of the properties Physique S and Chimique S of alginate. Its chemical composition varies according to the various species of algae, the various parts of the same plant and is prone to the seasonal changes. Nevertheless by raw material selection to the various properties, it is possible to manufacture a variety of alginate to the constant characteristics.

Manufactoring process

The alga is cut and cleaned after harvest. Then it is put to macerate in a mineral acid diluted to be demineralized. The alginate contained in the alga is thus transformed into alginic acid and, at the same time, certain undesirable components are eliminated. The demineralized algae are crushed in the presence of an alkali or of an alkaline salt in order to neutralize the alginic acid and to solubilize this one in the form of corresponding salt. The alginate is extracted and treated. It is precipitated, pressed, washed and dried, then neutralized, dried and ground with desired granulometry. One obtains various salts with the quite precise properties then: alkaline metal alginates (sodium, potassium, magnesium…) are water soluble while the alginic Acide and its calcic derivative (calcium, aluminum, iron…) there are practically insoluble. Soluble salts are dilsolvent at low temperature and form thick and viscous solutions, gel resistant to heat.

The alginate, product of moulding

There are tens of years, some artists started to be interested in alginate within the framework of their basic research. They are its characteristics used in the Dentistry for the catch of prints which held their attention. He gradually discovered in alginate employed by the dentists a material of Moulage, at the same time of a great flexibility, easy to use and particularly effective and powerful. These qualities make some single which, since one year or two, develops in the general public. But the alginate, matérieu of print, do not have great a deal to see with alginate, Raw material, used in the field, food, textile, pharmaceutical or different… The alginate is initially a generic name. In the dentistry, it corresponds to a product for prints being appeared as a powder containing between 12 and 20 components of which the alginate, like gelling raw material.

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