Vitamin A is derived from beta-carotene and carrots are a major source of this substance. Carotenoids, the group of plant pigments of which beta-carotene is a member, are so named because they were first identified in carrots. This ever-popular vegetable is also a source of disease-fighting flavonoids, and carrots contain a specific type of fibre, called calcium pectate, which may lower blood cholesterol.

With the exception of beets, carrots contain more sugar than any other vegetable, which makes them a satisfying snack eaten raw and a tasty addition to a variety of cooked dishes. In fact, some of the nutrients in carrots are more easily absorbed when the vegetable has been cooked, even briefly.

The carrot belongs to the Umbelliferae family, and is recognisable by its feathery leaves as a relative of parsley, dill, fennel and celery. In earlier times, carrots were small red, yellow, or purple roots; the elongated orange carrot, forerunner of today's familiar vegetable, was probably developed in the seventeenth century in Holland.

Buying

Many markets sell carrots in bunches with their tops still on, but usually at a higher price than bagged carrots. Some consumers see the tops as an indication of freshness, which indeed they are—if crisp and bright green. However, refrigeration and moisture-retaining packaging are the best preservers of freshness: If carrots are displayed unwrapped at room temperature, they will lose sweetness and crispness, with or without their leafy crown.

Look for well-shaped carrots; they should not be gnarled or covered with hairlike rootlets. Their colour should be a healthy reddish orange, not pale or yellow, from top to bottom (the darker the orange color, the more beta carotene is present). The top, or "shoulder," may be tinged with green, but should not be dark or black, both indications of age. However, the green part is likely to be bitter (it should be trimmed before eating); if carrots are very green on top, they should not be purchased. Also, avoid carrots that are cracked, shriveled, soft, or wilted.

Fairly young carrots are likely to be mild flavoured and tender, but, surprisingly, mature carrots are often sweeter, with a dense, close-grained texture. Regardless of its age, the smaller a carrot's core (the fibrous channel that runs the length of the vegetable), the sweeter the carrot: This is because its natural sugars lie in the outer layers. Usually, you can't see the core until you cut the carrot, but any carrots that have large, thick shoulders are likely to have large cores, too.

Storage
To preserve their flavour and texture, carrots should be refrigerated. Keep them in the coldest part of the refrigerator , in their original plastic bag. If they were purchased loose, place them in a perforated or loosely closed plastic bag. Don't store carrots together with apples, pears, or other fruits that produce ethylene gas as they ripen (even in the refrigerator, ripening of such fruits slows, but does not cease). Exposure to ethylene gas will turn carrots bitter.

If you buy carrots with "tops," twist or cut off the leaves before storing. Otherwise, the greens will soon wilt and decay; furthermore, moisture will be drawn from the roots, turning them limp and rubbery.

Preparation
Although bagged carrots usually look clean, bacteria from the soil may be present on the surface. So whether eating the carrots raw or cooking them, be sure to scrub them with a vegetable brush under running water, or peel them with a vegetable peeler or paring knife; then rinse thoroughly.

If you enjoy crunching on raw carrots, then do so. However, since carrots have tough cellular walls that the body cannot easily break down, cooking them just until crisp-tender actually makes their nutrients (including beta-carotene) more accessible.

Proper cooking brings out the sweetness in carrots. They can be left whole or cut into short lengths; halving them lengthwise will reduce cooking time. If you prefer, cut them straight or diagonally crosswise into "coins," or slice them into julienne (matchstick-size) strips. Grated or shredded carrots also cook very quickly. A food processor is handy for slicing or shredding.