Jerusalem Artichoke (Sunchoke)
1. Q. Is Jerusalem artichoke a good source of insulin?
A. In reference to the question about Jerusalem artichoke as a source of insulin, I believe the carbohydrate in Jerusalem artichoke is INULIN. Insulin is the (protein) hormone that controls glucose absorption by animal cells. If eaten, insulin is broken down to its component amino acids, which is why insulin is injected intradermally by dependent diabetics.
Inulin is a carbohydrate which breaks down to fructose. Fructose is not used to treat diabetes, but is considered a better sugar for most diabetics because it must be converted to glucose before being absorbed by cells.
Description - The Jerusalem artichoke is in no way related to the globe artichoke. It is a member of the Sunflower family and produces a similar flower. Plants may grow to a height of six to eight feet. It is perennial living from year to year. The edible tubers resemble potatoes but are rough and knobby.
Culture - The Jerusalem artichoke is widely grown in gardens in Texas. It is propagated by spring planting of tubers. Harvest the tubers in the fall for highest quality and refrigerate them immediately. Tubers left in the ground over winter will retain high eating quality for several months without developing sugar. The plant will freeze down but will grow back in the spring. It can rapidly become a weed in the home garden.
Availability - Common in Texas gardens, the Jerusalem artichoke is often available in supermarkets. It is nearly always found in "health food" stores. It is easily available in the period September through January, but often continues in store through the early spring.
Selection - Look for tubers that are free of bruises and cracks. Avoid those that are wilted and lack a firm, solid texture.
Storage - Tubers of the Jerusalem artichoke do not store as well as potatoes. Where the ground does not freeze in winter, they are best left in the ground and harvested as needed. Place the ones you buy in a sealed plastic bag and store them in the refrigerator. Long term storage at temperatures near freezing will result in the conversion of starch to sugar which causes them to have an off flavor.
Nutrition Information - The calorie content varies according to the length of storage. Freshly harvested sunchokes only contain 76 calories for a 3 ounce serving. As storage time increases so does the calorie count. A 3 ounce serving contains 34 percent of the RDA for iron for adult men.
Preparation - Peeling sunchokes is not necessary, although you may choose to do so depending on the recipe. The gnarled knobs make peeling between the crevices difficult. Using a vegetable brush helps to clean between the crevices. If you do peel sunchokes, plunge immediately into cold water and add a little vinegar or lemon juice or lime juice to prevent darkening.
Allow one to one and one-half pounds of sunchokes for four servings. One pound raw sunchokes equals 3 cups sliced and 2 cups when cooked and peeled. Sunchokes can be used in many of the same recipes as potatoes. Their crisp, white flesh is excellent raw, sliced into salads or served as a dip accompaniment. They can also be baked, boiled, mashed or fried, and prepared in combination with other vegetables. Add them to fresh vegetable or cream soups for a sweet, nutty taste.
Boiled - Cook whole sunchokes in boiling water for 10 to 20 minutes; larger tubers require longer cooking periods. Cutting the tubers prior to cooking shortens the cooking time.
Steamed - Steam small sunchokes over a small amount of boiling water for 12 to 15 minutes, until tender. Larger tubers require longer cooking. Avoid overcooking which makes them mushy.
Microwave Instructions - Peel one pound sunchokes if desired. Cut into 1/4" slices. To prevent darkening, place in 1 qt. water with 1 teaspoon lemon juice. Drain slices. Place in 2 qt. covered casserole with 1/4 cup water and teaspoon lemon juice. Microwave on high until fork tender, about six to nine minutes.