Friday, April 15, 2011

Types of potatoes

While there are close to 4000 different varieties of potato,it has been bred into many standard or well-known varieties, each of which has particular agricultural or culinary attributes. In general, varieties are categorized into a few main groups, such as russets, reds, whites, yellows (also called Yukons) and purples—based on common characteristics. Around 80 varieties are commercially available in the UK.

For culinary purposes, varieties are often described in terms of their waxiness. Floury, or mealy (baking) potatoes have more starch (20–22%) than waxy (boiling) potatoes (16–18%). The distinction may also arise from variation in the comparative ratio of two potato starch compounds: amylose and amylopectin. Amylose, a long-chain molecule, diffuses out of the starch granule when cooked in water, and lends itself to dishes where the potato is mashed. Varieties that contain a slightly higher amylopectin content, a highly branched molecule, help the potato retain its shape when boiled.



The European Cultivated Potato Database (ECPD) is an online collaborative database of potato variety descriptions, updated and maintained by the Scottish Agricultural Science Agency within the framework of the

European Cooperative Programme for Crop Genetic Resources Networks (ECP/GR)—which is organised by the International Plant Genetic Resources Institute (IPGRI).
Popular varieties (cultivars) include:

Blue varieties

Two dark-skinned potatoes on a white plate. A further potato is cut into sections to show the variety's purple-blue flesh, placed at lower-right on the plate.
Potato variety 'Blue Swede
The blue potato originated in South America. It has purple skin and flesh, which becomes blue once cooked. It has a slight whitish scab that seems to be present in all samples. The variety, called Cream of the Crop has been introduced into Ireland and has proved popular.


A mutation in the varieties' P locus causes production of the antioxidant anthocyanin.

Genetically-modified varieties

Genetic research has produced several genetically modified varieties. 'New Leaf', owned by Monsanto Company, incorporated genes from Bacillus thuringiensis, which conferred resistance to the Colorado potato beetle; 'New Leaf Plus' and 'New Leaf Y', approved by US regulatory agencies during the 1990s, also included resistance to viruses. McDonald's, Burger King, Frito-Lay, and Procter & Gamble announced they would not use genetically modified potatoes, and Monsanto published its intent to discontinue the line in March 2001.

The starch content of 'Amflora', waxy potato variety from the German chemical company BASF, has been modified to contain only amylopectin, making it inedible but more useful for industrial purposes. In 2010, the European Commission cleared the way for 'Amflora' to be grown in the European Union. Nevertheless, under EU rules, individual countries have the right to decide whether they will allow this potato to be grown on their territory. Commercial planting of 'Amflora' was expected in the Czech Republic and Germany in spring of 2010, and Sweden and the Netherlands in following years. Another GM potato variety developed by BASF is 'Fortuna'. In 2010, a team of Indian scientists announced they had developed a genetically modified potato with 35 to 60% more protein than non-modified potatoes. Protein content was boosted by adding the gene AmA1 from the grain amaranth. They also found 15 to 25% greater crop yields with these potatoes. The researchers expected that a key market for the GM potato would be the developing world, where more than a billion people are chronically undernourished.

New non-GM varieties

Other new potato cultivars are conventionally bred. For example, on 22 September 2007, Benguet State University (BSU) announced that four potato varieties—'Igorota', 'Solibao', 'Ganza' and one not yet officially named—possess more than 18% dry matter content required by fast-food chains to make crispy and sturdy French fries.Since 2005, a natural 100% amylopectin waxy potato variety called 'Eliane' is being cultivated by the starch company AVEBE.
Some horticulturists sell chimeras, made by grafting a tomato plant onto a potato plant, producing both edible tomatoes and potatoes. This practice is not very widespread.

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