Jerusalem artichoke
The Jerusalem artichoke, also called sunroot, sunchoke, wild sunflower, topinambur, or earth apple, is a species of sunflower native to central North America. It is cultivated widely across the temperate zone for its tuber, which is used as a root vegetable.
Description
Helianthus tuberosus is a herbaceous perennial plant growing to tall with opposite leaves on the lower part of the stem but alternate towards the top. The leaves have a rough, hairy texture. Larger leaves on the lower stem are broad ovoid-acute and can be up to long. Leaves higher on the stem are smaller and narrower.The flowers are yellow and produced in capitate flowerheads, which are in diameter, with 10–20 ray florets and 60 or more small disc florets. The flowers are briefly fragrant, giving off a light, vanilla-chocolate perfume.
The tubers are often elongated and uneven, typically long and thick, and vaguely resembling a ginger root in appearance, with a crisp and crunchy texture when raw. They vary in color from pale brown to white, red, or purple.
Culinary use
The tubers can be eaten raw, cooked, or pickled.Before the arrival of Europeans, indigenous peoples cultivated H. tuberosus as a food source. The tubers persist for years after being planted, so the species expanded its range from central North America to the eastern and western regions. Early European colonists learned of this and sent tubers back to Europe, where they became a popular crop and naturalized there. It later gradually fell into obscurity in North America, but attempts to market it commercially were successful in the late 1900s and early 2000s.
The tuber contains about 2% protein, no oil, and little starch. It is rich in the carbohydrate inulin, which is a polymer of the monosaccharide fructose. Tubers stored for any length of time convert their inulin into its component, fructose. Jerusalem artichokes have an underlying sweet taste because of the fructose, which is about one and a half times as sweet as sucrose.
It has also been reported as a folk remedy for diabetes: since inulin is not assimilated in the intestine, it does not cause a glycemic spike as potatoes would. Temperature variances have been shown to affect the amount of inulin the Jerusalem artichoke can produce. It makes less inulin in a colder region than when it is in a warmer region.
Etymology
Despite its name, the Jerusalem artichoke has no relationship to Jerusalem, and it is not a type of artichoke, though the two are distantly related as members of the daisy family. The most probable explanation is that Italian settlers in the United States called the plant girasole, the Italian word for sunflower, because of its familial relationship to the garden sunflower. Over time, the name girasole was corrupted by English-speakers to Jerusalem. Various other names have been applied to the plant, such as the French or Canada potato, topinambour, and lambchoke. Sunroot is a literal translation of the Virginia Algonquian term kaishucpenauk reported in 1588, this naming is similarly reflected in Ojibwe as ᑮᓯᓲᒌᐱᒃ giizisoojiibik. Sunchoke, a name by which it is still known today, was invented in the 1960s by Frieda Caplan, a produce wholesaler trying to revive the plant's appeal.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 its taste was similar to that of an artichoke.
The name topinambur, in one account, is attributed to the Brazilian coastal tribe called the Tupinambá, several members of which were brought to France in 1613 at the same time that the tubers were beginning to make an appearance on French tables. The New World connections were conflated, the plant being misattributed to Brazil, resulting in the name toupinambeaux being applied to the tubers in French. By 1658, topinambour is found. From there, the word made its way into other European languages.
Cultural significance
According to Iroquois mythology, the first sunchokes grew out of Earth Woman's feet after she died giving birth to her twin sons, Sapling and Flint.History
Jerusalem artichokes were first cultivated by the Indigenous peoples of the Americas, though the exact native range of the species is unknown. Genome analysis has ruled out the common sunflower as an ancestor, and instead points to hybridization between the hairy sunflower and the sawtooth sunflower.The French explorer Samuel de Champlain discovered that the native people of Nauset Harbor in Massachusetts had cultivated roots that tasted like artichoke. The following year, Champlain returned to the same area to discover that the roots had a flavor similar to chard and was responsible for bringing the plant back to France. Sometime later, Petrus Hondius, a Dutch botanist, planted a shriveled Jerusalem artichoke tuber in his garden at Terneuzen and was surprised to see the plant proliferate. Jerusalem artichokes are so well-suited for the European climate and soil that the plant multiplies quickly. By the mid-1600s, the Jerusalem artichoke had become a very common vegetable for human consumption in Europe and the Americas and was also used for livestock feed in Europe and colonial America. The French were particularly fond of the vegetable, which reached its peak popularity at the turn of the 19th century. The Jerusalem artichoke was titled 'best soup vegetable' in the 2002 Nice Festival for the Heritage of French Cuisine.
The French explorer and Acadia's first historian Marc Lescarbot described Jerusalem artichokes as being "as big as turnips or truffles," suitable for eating and taste "like chards, but more pleasant." In 1629, the English herbalist and botanist John Parkinson wrote that the widely grown Jerusalem artichoke had become very common and cheap in London, so much so "that even the most vulgar begin to despise them." In contrast, when they had first arrived in England, the tubers had been "dainties for the Queen."
Lewis and Clark ate the tubers, prepared by an indigenous woman, in modern-day North Dakota.
They have also been called the "Canadian truffle".
Invasive potential
Biological characteristics
Its rapid growth and its ability to reproduce from buried rhizomes and tubers facilitates the Jerusalem artichoke's uncontrolled spread. The vegetative propagules can be transported via rivers and water streams and begin a new population on riverbanks. Dispersal by animal is also possible, as animals feed on tubers and rhizomes and excrete the propagules in new areas. With humans' cultivation, there is also a risk of the plant's unintended escape into the wild. It can also be propagated by seed. Its relatively long flower period enables the Jerusalem artichoke to increase its reproductive potential.Origins and distribution
Originating in North America, the Jerusalem artichoke can now be found in several countries in North and South America, Europe, Asia, and Australia. In Central Europe it is one of the most expanding invasive plant species. It can grow in many geo-climatic regions and different types of soils. However, Jerusalem artichoke prefers moist habitats and seems to be less tolerant of dry conditions.Suppression of native plant species
Because of its ecological and biological attributes, the Jerusalem artichoke is highly competitive with other plant species. For instance, the carbohydrates in the tubers serve as an energy source for rapid growth in spring. The plant expands rapidly and creates shading, which has a suppressing effect on neighbouring plants. Therefore, the risk of outcompeting and repressing the growth of native plants is increased.Cultivation and use
Unlike most tubers, but in common with many other members of the Asteraceae, Jerusalem artichoke tubers store their carbohydrate as inulin rather than as starch. This has made them an important source of inulin used as a dietary fiber in food manufacturing.Jerusalem artichoke can propagate with seeds and tubers but the use of tubers leads to higher yields. For planting, the tubers are cut into pieces with three to five buds that are placed in depth in the soil. Jerusalem artichoke has low nutrient requirements and needs less nitrogen than other energy crops. The competitiveness against weeds is high, making weed control easier but also making it harder to grow a different culture afterward, since some small tubers usually remain in the ground after harvest. The plant's high competitiveness may be due to allelopathic effects, high plant size, and rapid growth rate.
Crop yields are high, typically for tubers, and green weight for foliage. Tubers remaining in the ground lie dormant over winter and can handle temperatures as low as. Jerusalem artichoke also has potential for production of ethanol fuel, using inulin-adapted strains of yeast for fermentation.
The tubers are used for cooking and baking in the same ways as potatoes, but unlike the potato, they can also be eaten raw. They have a similar consistency and, in their raw form, have a similar texture but a sweeter, nuttier flavor. When raw and sliced thinly, they are fit for a salad. Their inulin form of carbohydrates give the tubers a tendency to become soft and mushy if boiled, but they retain their texture better when steamed. The inulin cannot be broken down by the human digestive system but bacteria metabolize it in the colon. This can cause flatulence and, in some cases, gastric pain. John Gerard's Herbal, printed in 1621, quotes the English botanist John Goodyer on Jerusalem artichokes:
Jerusalem artichokes have 650 mg potassium per 1 cup serving. They are also high in iron and contain 10–12% of the USRDA of fiber, niacin, thiamine, phosphorus, and copper.