The most neglected white wines today are those of the Loire valley. The home of some of France's most prestigious whites, as well as a succession of regal cha~teaux, the Loire has in recent years lost market share to that irresistible force, chardonnay. Loire whites are made instead from chenin blanc and sauvignon blanc, and their fine, highly individualistic styles are unknown to many Americans.

This is a shame. Chardonnay is a serviceable grape that is made into great wine in Burgundy and in California. But chardonnay is not all things to all food. Neither is the American style of sauvignon blanc -- usually a smoky rendition of that grape, justly made famous by Robert Mondavi and emulated by other American producers. Those sauvignons are fine, but there are alternatives from the Loire.

The sauvignons from Sancerre and Pouilly-Sur-Loire in the upper Loire valley, for instance, tend to have grassy bouquets and a lush complexity. The same depth is found in chenin blancs made in Vouvray and other Loire valley locales. Some of these wines go well with seafood, but many are even better suited to autumn fare -- foie gras, country pa~te's and distinctive cheeses.

A particularly lovely, full-bodied sancerre is the '85 Cuve'e des Moulins Bales, bottled by Celestine Blondeau; it provides a good companion for salmon and costs about $8.50. Blondeau also produces a good pouilly fume', Les Rabichottes, for about the same price.

For a big, flavorful, slightly grassy pouilly fume' -- one of the best expressions of sauvignon blanc from the Loire -- try the '83 Chatelain Cuve'e Prestige. It costs a bit more than a good California sauvignon, but the flavor is entirely different. The grassiness doesn't overwhelm, and the finish is full and long.

Downstream in Anjou, from the area around Rochefort, come classic chenin blancs that require a few years in bottle to demonstrate their full power and complexity. The good ones are not cheap -- they cost about $20 -- but compared with white burgundies, sauternes and California chardonnays of similar age, they are still bargains. One is the '81 Domaine des Baumard Quarts de Chaume, from Rochefort-sur-Loire -- a beautiful, rich wine that has surprising adaptability despite the fact that it is sweet. Good balance and acid give this wine a crisp finish. It is fine with pa~te' and fine on its own.

Another impressive chenin is the '82 Coteaux du Layon, from the Domaine de la Soucherie, similarly rich but slightly sweeter than the Baumard; it is well suited to veal or chicken in a cream sauce, or to fruit tarts or nuts -- even cookies -- served as a finale to the meal.

Well-made chenin from the Loire gets mellower and nuttier as it ages and can be drunk with anything from turbot to seafood quenelles. An '82 Clos de la Coule'e de Serrant I recently tasted, one of the prizes from a beautiful little 17-acre estate just southwest of the city of Angers, had a cinnamon-like nose and great body.

The Loire, France's longest river, is the host to many other wines in addition to its sauvignon and chenin blancs. One of the most famous, and still one of the great white wine bargains, is muscadet, made from the grape of the same name. It is produced near the river's mouth and is renowned as an accompaniment for oysters and other shellfish. "Sur lie" on the label of a bottle of muscadet refers to the practice of leaving the wine exposed to the skins and pips of the muscadet grape until the time of bottling, which supposedly enhances the wine's character.

Some muscadets are too lean and green for delicate foods, but the dryness of a good muscadet suits most meals, and also combines with cre`me de cassis to make a superior kir. All muscadets must be drunk in their youth.

A recommended "sur lie" muscadet is Cha~teau du Cle'ray, for about $6.50, made by Sauvion. Les Bois Battus, also made by Sauvion, sells for less than $4, while indifferent chardonnays from other climes cost twice as much. ::