For those who want a break from the colorful, crisp apples now in season, there is another, often overlooked fall fruit brimming from produce shelves: pears.

Pears are available year-round, but many varieties have a peak season that starts now and runs through the winter. An ancient fruit known to grow in China 2,000 years ago, pears were first sold in the United States in 1817 by Enoch Bartlett of Dorchester, Mass.

Bartlett pears now account for about 75 percent of the pears consumed in the United States, according to the United Fresh Fruit & Vegetable Association.

Other major varieties now available in grocery stores and fruit stands include Anjou, Bosc, Comice, Nelis, Forelle and Seckel. Nearly all are grown in the Pacific Northwest, which provides the ideal climate for this fruit.

The nutritional advantage of pears is that they contain no fat, are high in fiber and relatively low in calories. One five-ounce pear, for example, has 98 calories, according to the U.S. Department of Agriculture.

Eaten with the skin, it provides about five grams of fiberQa good start on the 25 to 30 grams recommended for daily consumption.

Pears are rich in potassium, which is important for the heart, as well as a necessary nutrient for muscle contraction. Potassium also aids in transmission of signals by the nerves and helps the body metabolize carbohydrates and proteins.

Pears pack a lot of vitamin C: One five-ounce pear contains about 11 percent of the recommended daily allowance and is a good source of vitamin E and riboflavin.

Unlike nearly all other fruit, pears do not mature well on the tree, according to the United Fresh Fruit & Vegetable Association. Instead, pears must be picked first, then allowed to ripen. That means consumers must be prepared to judge which pears are ripe on the produce shelves.

Color alone is no sure guide to gauging ripeness. Yellow Bartlett pears turn golden when ripe. Red Bartletts become crimson as they ripen.

But many other varieties show virtually no change in color as they mature, according to the Produce Marketing Association.

To judge whether a pear is ripe, apply gentle pressure with your thumb near the base of the stem. If it yields slightly, it's ready to eat, advise fruit growers.