People who love eggplant and who cook with the familiar, deep-purple variety sold in every American grocery are depriving themselves of an even finer eating experience.

They also are taking some preparation steps that don't necessarily come with eggplant. The standard first step in most recipes is to cut and salt the eggplant and let it stand for 30 minutes, after which its bitter juices can be rinsed away; it's then deemed ready to cook.

This salting and rinsing is not necessary, however, with the long, thin, bright purple variety sometimes called "Chinese eggplant" or the smaller, nearly black "Japanese eggplant." Compared to their larger, common cousin, they're sweet, tender and relatively seedless, and processing them before they're cooked is a waste of time as they have little bitterness to begin with. Just cut them up and cook them.

We associate eggplant with the Mediterranean, but it was unknown in that part of the world during ancient times; and the Italians didn't even see an eggplant until around the 15th century. Eggplants are natives to Southeast Asia, and from India east through China and Japan, they have been eaten for thousands of years.

Eggplants are white as well as purple, and it's the smaller, egg-shaped white ones that give them their name. Southeast Asians also cultivate marble-sized eggplants, green and white, known as "pea eggplants," for pickling or cooking in curry dishes. These have recently appeared fresh in some Asian markets in the United States.

One would imagine, as with most of our vegetables, that the standard purple eggplants were cultivated for size and because they can sit longer -- though they toughen -- without any outward appearance of deterioration. On the other hand, the Asian varieties, like any fresh vegetable, soften and wrinkle quickly. Even if just picked, the Asian eggplants are better -- they're almost good enough to be eaten raw -- and once a cook has used them, it's difficult to go back to the old standard.

Not only is salting not required, but peeling Asian eggplants is unnecessary for most dishes. Often with the large eggplants the skin is tough and unedible. The Asian eggplants also cook in far less time. Cut into rounds for example, they may be saute'ed in oil with peppers, herbs and salt and pepper over medium heat in just a few minutes. Allowed to cool, such a dish makes an excellent summer salad. SICILIAN CAPONATA (4 servings)

1 1/2 pounds, about 3, oriental eggplant

9 tablespoons olive oil

1 cup diced celery

1 yellow onion, diced

1 1/2 cups peeled diced tomatoes, canned or fresh

2 tablespoons capers, drained

2 tablespoons toasted or fried pine nuts

2 tablespoons golden raisins

8 large black olives, coarsely chopped

2 tablespoons sugar

1/2 cup red wine vinegar

1 1/2 teaspoon salt

1 teaspoon freshly ground pepper

Cut eggplants into 3/4-inch cubes. Heat 6 tablespoons of the olive oil in a large skillet and saute' the eggplant over medium heat for 3 to 5 minutes. Remove to a bowl with a slotted spoon leaving whatever oil is left. Add the remaining 3 tablespoons oil and add the celery and onions. Cook, stirring, until the onions are translucent. Add the tomatoes and continue to cook and stir for 2 minutes. Return the eggplant and the remaining ingredients to the skillet and allow to cook, stirring from time to time, for another 10 to 12 minutes. Turn off the heat, allow to cool to room temperature, and serve with crusty bread. This may be prepared well in advance. It may even be refrigerated overnight as long as it warms to room temperature before serving.