Know your Jerusalem Artichoke

Know your Jerusalem Artichoke - Introduction

  • The Jerusalem artichoke, Helianthus tuberosus, is a species of sunflower native to the eastern United States, from Maine west to North Dakota, and south to northern Florida and Texas.
  • It is also cultivated widely across the temperate zone for its tuber, which is used as a root vegetable.

Know your Jerusalem Artichoke - Common names

  • Jerusalem artichoke is also called the sunroot, sunchoke, earth apple or topinambur.

Know your Jerusalem Artichoke - Botany

  • It is a herbaceous perennial plant growing to 1.5–3 metres (4 ft 10 in–9 ft 10 in) tall with opposite leaves on the lower part of the stem becoming alternate higher up. 
  • The leaves have a rough, hairy texture and the larger leaves on the lower stem are broad ovoid-acute and can be up to 30 centimetres (12 in) long and the higher leaves smaller and narrower.
  • The flowers are yellow, produced in capitate flower-heads which are 5–10 centimetres (2.0–3.9 in) in diameter, with 10–20 ray florets.
  • The tubers are elongated and uneven, typically 7.5–10 centimetres (3.0–3.9 in) long and 3–5 centimetres (1.2–2.0 in) thick, and vaguely resembling ginger root, with a crisp texture when raw. 
  • They vary in colour from pale brown to white, red or purple.

Know your Jerusalem Artichoke - 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 fuel, using inulin-adapted strains of yeast for fermentation.

Know your Jerusalem Artichoke - Cultivation

  • 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.

Know your Jerusalem Artichoke - Cuisine

  • The tubers have a consistency much like potatoes, and in their raw form have a similar texture to potatoes, but a sweeter, nuttier flavour; raw and sliced thinly, they are fit for a salad. 
  • The carbohydrates give the tubers a tendency to become soft and mushy if boiled, but they retain their texture better when steamed. 
  • The inulin is not well digested by some people, leading in some cases to flatulence and gastric pain.
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