Europe in the lead

The production of potato starch for non-nutritional purposes is predominantly an activity of Western European nations. Within the EU, it is fixed by quotas: the total amount is almost 2 million tonnes, of which the largest share goes to Germany (650,000 tonnes), followed by the Netherlands (507,000 tonnes) and France (265,000 tonnes). More than 40 percent of the starch produced in the European Community is used for non-food purposes. Native potato starch shows a higher viscosity than starch from wheat or maize. It possesses good water-uptake and swelling properties, as well as low thermal and electrical conductivity.

For starch production, simple late-ripening potato varieties are preferred. Their starch content of 17 to 20 percent is markedly higher than that of food potatoes (around 10%). On arriving at the starch factory, the tubers are first washed to remove any earth still sticking to them. Next, they are rasped and processed to produce a slurry, from which the potato starch is separated and dried in a succession of steps. The result is a highly pure native starch with a moisture content of around 20 percent.

From glue to plastics…

The potato starch is processed further to produce raw materials for the paper, chemical, pharmaceutical and textile industries. Adhesives derived from potato starch are also valued in medicine, because they are without any health concerns. And many a stamp remains stuck to a holiday postcard thanks to starch and water.
Potato starches can also be processed into films, carrier bags, disposable cutlery and packaging materials. These biomaterials can replace petroleum oil-based products; they are capable of being sprayed, formed or expanded into various shapes and containers. Depending on how they are formulated, materials based on plant starches are biologically degradable.

At present, the worldwide capacity for producing bioplastics is less than 100,000 tonnes a year; however, the European Bioplastics Association forecasts a rapid increase in capacity, with worldwide production exceeding 1.5 million tonnes by 2011, not least because of high oil prices and the question of climate change. In countries such as France, Italy and Australia, there is a political will to introduce biologically-degradable carrier bags. This will of course mean greater demand for potato starch.

… to washing agents and fuel

Potato starches are also used to produce bio-surfactants that can replace synthetic detergents in washing powders, soaps and shampoos. Moreover, potato starch is fermented and distilled into bioethanol, which is being mixed with conventional petrol in a number of industrial countries.
In the future, biotechnology may improve the efficiency with which renewable raw materials are obtained from potatoes, because gene technology can be used to alter a variety’s starch profile.