Solanum tuberosum L.
How Many Species of Potatoes Worldwide?
Potato is a member of tomato or eggplant family, Solanaceae. The species is indigenous to the Andes region (Peru, Bolivia, Equador, Chile, and Colombia) where some closely related species are cultivated. In total there are about eight or nine cultivated potato species, but the major species grown worldwide is Solanum tuberosum (a tetraploid with 48 chromosomes).
Following centuries of selective breeding there are now over 5000 different cultivars of potatoes worldwide, 3000 in the Andes region alone.
Potatoes can be divided into four major Cultivar Groups, namely, the Russets, reds, whites and yellows (also called Yukons). The part of the plant used is the swollen underground stem known as the tuber. It stores surplus carbohydrates to feed the leafy green areas of the plant.
Production of Potatoes
Potato is a cool season crop so tuber formation stops at 27°C (81°F). China is the largest producer of potatoes. Genetically modified varieties of potatoes have met public resistance in the USA and European Union.
Who Eats Potatoes?
Potatoes were first introduced out of Andes more than 4 centuries ago and have since become an integral part of the worlds food supply. It’s the fourth largest food crop after maize, wheat and rice. 2/3 of global production is eaten by humans and the rest is fed to animals or used to produce starch.
More than a billion people worldwide eat potato. China is the largest consumer of potatoes. Potato remains an important crop in eastern and Central Europe with the highest per capita production. Americans consume 57kg (126Ib) potatoes per person per year on average. Potato the leading source of vitamin C in the American diet.
Nutritional value per 100g (3.5oz): 77kcal and 15% starch. The notable minerals as per RDA are vitamin B6 23%, vitamin C (24%), potassium 9%, phosphorus 8%
Use of Potatoes
As mentioned before, 2/3 of global production is eaten by humans and the rest is fed to animals or used to produce starch.
65% of America’s potatoes are sold in various convenience forms like fries and hash browns with lots of added salt and fat.
Canned potatoes: are nutritional but may contain more than 400mg of sodium per cup as compared to freshly cooked that has only 6mg sodium per cup.
Toxicity in Potatoes
All green parts of the potato plant except the tubers contain the toxic alkaloid solanine, and are unsuitable for consumption. Solanine is also found in the green parts of the eggplant and tomato, plants.
Potato produces small green fruits, the size of cherry tomatoes, each containing about 300 seeds. Potato fruit is not edible.
How to Store Potatoes
Commercially grown potatoes are usually cured after harvest to improve skin set. Potatoes should be stored in a cold dark, well ventilated area with temperatures of about 4°C(39°F).
Temperatures below 4°C (39F) converts potato starch into sugar which alters taste and cooking quality. Please do not keep potatoes in the Fridge.
Household storage: 7-20°C (45-50°F), preferably in a dark well ventilated area.They will keep for several weeks.
Important Tip: if potatoes develop green areas or start to sprout, these areas should be trimmed before using the potato. Remember we discussed that green parts of the potato plant contain toxic alkaloids known as solanine.
Wild Species of Potatoes
There are about 200 wild species and sub-species many of which can be cross bred with the cultivated varieties.