This week's look at what's new, bountiful and even mysterious on the produce aisle.

Americans are the grapefruit gurus. Florida produces 37 percent of all grapefruit grown in the world. Who deserves the Golden Rind award? Give it to French Count Odette Phillipe, who planted the first grove near Tampa in 1823. More grapefruit finds its way to market from California, Arizona and the Rio Grande Valley in Texas. And there are several varieties to choose from in stores during the harvest season of September to June.

Like them sour? Like them sweet? There is a grapefruit for everyone.

The most popular grapefruit in this country is the sweet, mild-flavored, seedless Ruby Red. At Safeway stores, a shopper will choose a Ruby over a white-fleshed grapefruit by a ratio of 9 to 1. Be on the lookout for the pretty Thompson Pink from Florida as well as the sweet Rio Red from down Texas way. They will hit stores in the weeks ahead. The very juicy and full-flavored Marsh Whites, seedless grapefruits with a strong following in Japan and Europe, are piled high in supermarkets now.

Grapefruit is available year-round but January is when this fruit is at its best. "The advent of cold weather enlivens that balance of sweet and tangy," says Falco Witkamp, director of fresh fruit marketing for the Florida Department of Citrus. "And we just had a good cold snap."

The pomelo, an ancestor of the grapefruit, is widely grown in Malaysia, Indonesia and China and some are commercially grown in Florida. Once found exclusively in Asian markets, this fragrant, thick-skinned mammoth, measuring up to one foot in diameter, with a pith as deep as a doormat, is now available in supermarkets. Like its kin, it has interior pulp that can vary in color from yellow to pink, from juicy to dry and from sweet to tart.

HOW TO BUY GRAPEFRUIT: Choose smooth, shiny, firm fruits that feel heavy for their size. A hint of green or a blemish on the peel does not affect the quality of the fruit.

HOW TO STORE THEM: Fresh grapefruit will keep, at room temperature, for up to one week. But they will stay firmer and better-looking and remain fresh longer (two to three weeks) in the crisper drawer of the refrigerator. The optimum temperature is between 45 and 48 degrees. Never store any type of citrus in a plastic bag. Drops of moisture that form on the interior of the bag promote mold growth.

HOW TO USE THEM: There are those who roll out the grapefruit only at breakfast, served chilled, sliced in half, with a sprinkle of sugar on top. More adventurous cooks know that grapefruit sections or half a fruit is splendid topped with dark brown sugar or flavored honey and popped under the broiler. Properly peeled sections add color, texture and a cleansing citrus flavor to salads. Pair with avocado and a vinaigrette, smoked salmon or plain cottage cheese. Tart grapefruit juice sorbet topped with a twist of candied grapefruit peel is an entertaining and light dinner course. Acidic grapefruit is a perfect companion to fish. After removing the membrane from sections of both white and red fruits, spoon the fruit over grilled salmon or scallops. Garnish with minced cilantro stems and chives.