Here are some facts about root vegetables:
Beets: 50 calories per 250 ml (1 cup) of cooked diced beets. Good source of folacin and a source of vitamin C and potassium. Choose firm small to medium-size beets. The outside may be rough, but should be dry and taut. Loosely wrap in paper towel and keep in refrigerator crisper for up to one week. They can also be kept in a root cellar or other cool location. Scrub under running water to remove any trace of dirt and dry on paper towel.
Carrots: Low in calories and an excellent source of beta-carotene; also contain fibre, potassium and vitamin C. When buying, green "shoulders" may indicate bitterness. Refrigerate carrots in their original packaging for up to two weeks or as long as four weeks for mature carrots.
Celeriac: 42 calories per 100 grams. Good source of vitamin K, phosphorus, iron, calcium, copper and manganese, moderate amounts of vitamin C. Very gnarly, knobby looking. Store in a plastic bag in the crisper. To prepare, scrub and wash the root in cold running water to remove surface soil. Dry, trim at top and base, then cut the entire tuber into four quarters. Scrape off its outer skin using a thick knife. Rub a lemon or orange slice over the cut surface to prevent it from turning brown.
Parsnips: Good source of folate and potassium and a source of fibre. They also contain phytochemicals that may help lower the risk of cancer. Select firm, unshrivelled medium-sized parsnips (large ones can be woody). Parsnips will keep for several weeks in the refrigerator, stored in a plastic bag.
Rutabagas: Relatively low in calories, a good source of vitamin C and a source of folacin and fibre. They contain phytochemicals that may help to lower the risk of cancer. To microwave, prick a one-kilogram (2.2-pound) rutabaga in several places. Wrap in paper towel; place in a microwavable dish. Cook on high, turning halfway through, for 14 to 17 minutes or until knife easily pierces centre. Let stand, wrapped in foil or covered with an inverted bowl, for 10 minutes. Mash.
Sweet potatoes: A nutrition powerhouse, high in vitamin A (beta carotene) and vitamin C. Baked in its skin, a 100-gram (3 1/2-ounce) serving contains 141 calories. Select round, firm roots. Handle carefully to prevent bruising. Store in a cool, dry place at about 13 C (55 F). Do not refrigerate as this will cause them to develop a hard core.
Source: Foodland Ontario and other sources.