Potato and Tuber Crops

Description

• It is an herbaceous perennial plant growing to 1.5–3 m 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 cm long and the higher leaves smaller and narrower.
• The flowers are yellow, produced in capitate flower heads which are 5–10 cm diameter, with 10–20 ray florets.
• The tubers are elongated 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.
• The tubers of Jerusalem artichoke contain fewer calories than potatoes, and they are especially high in vitamin A, the B-complex, potassium and phosphorus.
• They contain the polysaccharide inulin instead of starch, which is a nutritious food for diabetics and hypoglycemics.
• The hydrolysis of inulin yields fruit sugar (D-fructose), while true insoluble starch (amylopectin) yields D-glucose.
• Starch (amylum) is actually composed of two polymers, soluble starch (amylose) and insoluble amylopectin. Starch polymers are packed into membrane-bound starch grains or amyloplasts within plant cells.
• Sugars from the digestion of inulin do not elicit rapid insulin production compared with other starchy foods.
• Jerusalem artichokes have 650 mg potassium per 1 cup (150g) serving.
• They are also high in iron, and contain 10-12% of the US RDA of fiber, niacin, thiamine, phosphorus and copper.