Strength

Natural, organic, odourless and tasteless chemical compound of carbon, hydrogen and oxygen, belonging to the polysaccharides, which is stored by plants in above or below ground nutrient tissues as assimilation products and important reserve product (the animal or human organism as well as fungi use glycogen as carbohydrate storage).

Chemically, starch consists of a non-uniform polysaccharide mixture of exclusively alpha-glycosidically linked D-glucose building blocks with the empirical formula: (C6H10O5)n. The number of building blocks ranges from 300-1000.

Starch consists of 15-30% amylose and 70-85% amylopectin.

Amylose is stored inside the starch grains, amylopectin in the outer shell. They differ in the type of molecular structure and in their molecular size.

Representatives are:

• Wheat starch (Amylum tritici)
• Potato starch (Amylum Solani)
• Rice starch (Amylum Oryzae)
• Maize starch (Amylum Maydis)
• Horse chestnut starch

Rice starch, wheat starch, maize starch is still occasionally used as powder base or as binder in contact powders

The different vegetable starches differ microscopically in the shape and size of their starch grains (size between 2um and 45um) and thus also in their pharmaceutical properties. In water, the starch grains show a clear stratification, which is caused by the fact that around an inner, less dense part, the so-called "formation centre", further layers with unequal refraction of light organise themselves like a shell.

Starch is insoluble in organic solvents and in cold water. In water, starch swells with an increase in volume of 20-100%. When it boils, it forms a colloidal solution which solidifies into a gel when it cools.

Starch is split by enzymes (alpha-, beta-amylases). Dextrins or disaccharides are formed during the enzymatic cleavage. This takes place, for example, inside plant cells, starch provides plants with the starting material for building their cell walls. The animal and human organism can also split starch enzymatically by amylases. Resistant starch cannot be attacked by amylases due to physical peculiarities. It is therefore one of the non-absorbable fibres.