The Jerusalem artichoke (Helianthus tuberosus), also called the sunroot or sunchoke or
topinambur, is a species of sunflower native to eastern North America, from Maine west to North
Dakota, and south to northern Florida and Texas.[1] It is also cultivated widely across the temperate world
for its tuber, which is used as a root vegetable.[2]
Jerusalem artichoke flowers
It is a herbaceous perennial plant growing
to 1.5–3 m tall. the leaves are opposite on the lower part of the stem, alternate higher up; the
larger leaves on the lower stem are broad ovoid-acute and can be up to 30 cm long, the higher leaves smaller and narrower; they
have a rough, hairy texture. The flowers are yellow, produced in flowerheads 5–10 cm diameter, with 10–20 ray florets. The tubers are gnarly
and uneven, typically 7.5–10 cm long and 3–5 cm thick, and vaguely resembling ginger root, with a
crisp texture when raw; they vary in color from pale brown to white, red or purple.[2][3]
Etymology
Jerusalem artichoke tubers
Despite its name, the Jerusalem artichoke has no relation to Jerusalem, and
it is not a type of artichoke, though they are in the same family. The name Jerusalem is
due to folk etymology; when the Jerusalem artichoke was first discovered by Europeans it
was called Girasole, the Italian word for sunflower. The Jerusalem artichoke is a type
of sunflower, in the same genus as the garden sunflower Helianthus annuus. Over time the name Girasole transformed into
Jerusalem, and to avoid confusion some people have recently started to refer to it as sunchoke or sunroot, which is
closer to the original Native American name for the plant.
The artichoke part of the Jerusalem artichoke's name comes from the taste of its edible tuber.
Samuel de Champlain, the French explorer, sent the first samples of the plant to France, noting that its taste was similar to an
artichoke.[citation needed]
History
Jerusalem artichokes were first cultivated by the Native Americans
(who called them "sun roots") long before the arrival of the Europeans; this extensive
cultivation makes the exact native range of the species obscure.[1] The French explorer Samuel
de Champlain found them being grown at Cape Cod in 1605.
Cultivation and uses
Unlike most tubers, but in common with other members of the Asteraceae (including the
artichoke), the tubers store the carbohydrate inulin (not to be confused with insulin) instead of starch. For this reason, Jerusalem artichoke tubers are an
important source of fructose for industry. The crop yields are high, typically 16–20
tonnes/ha for tubers, and 18–28 tonnes/ha green weight for
foliage. Jerusalem artichoke also has a great deal of unused potential as a producer of ethanol for fuel, using inulin-adapted
strains of yeast for fermentation.[2].
Jerusalem artichokes are easy to cultivate, which tempts gardeners to simply leave them completely alone to grow. However the
quality of the edible tubers degrades unless the plants are dug up and replanted in fertile soil. This can be a chore, as even a
small piece of tuber will grow if left in the ground, making the hardy plant a potential weed.
The carbohydrates give the tubers a tendency to become very soft and mushy if boiled, so it is, as with most vegetables, best
to steam them lightly to preserve their texture. The inulin is not well digested by some people, leading to the misconception
that sunchokes are not edible or an assumption that they cause flatulence and gastric pain. Gerard's Herbal, printed in
1621, quotes the English planter John Goodyer on Jerusalem artichokes:
"which way soever they be dressed and eaten, they stir and cause a filthy loathsome stinking wind within the body, thereby
causing the belly to be pained and tormented, and are a meat more fit for swine than men." [4]
This account was not typical of most peoples' experience eating the tubers and they were cultivated in the gardens of Native
America and the Pilgrims. They continue to be planted and consumed.
Jerusalem artichokes are sold in the produce departments of many supermarkets. They are usually pre-packaged in a plastic tray
labeled for specialty food sales, but some stores carry them loose in baskets or bins, where they look like kiwi-sized gnarled
potatoes or ginger root. The freshest roots are plump and vibrant in appearance. If they are left too long in the open, they
become wrinkled and soft and can develop a bitter taste. Fresh ones, properly steamed, have a mild, sweet and nutty flavor that
requires no additional sauce or condiment to accentuate it.
Jerusalem artichokes have 650 mg. potassium per cup serving, and 115 calories. They are very high in iron, and contain 10-12%
of the RDA of fiber, niacin, thiamine, phosphorus and copper.
References
- ^ a b Germplasm Resources Information Network: Helianthus
tuberosus
- ^ a b c Purdue University
Center for New Crops & Plants Products: Helianthus tuberosus
- ^ Huxley, A., ed. (1992). New RHS Dictionary of Gardening.
Macmillan ISBN 0-333-47494-5.
- ^ Gerard's Herbal, cited in Davidson A. (1999). The Oxford Companion to Food,
first edition. Oxford University Press ISBN 0-19-211579-0.
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