he base provides the flavor and the whites provide the "lift". Foods commonly used for the base in a soufflé include cheese, jam, fruits, berries, chocolate, banana and lemon (the last three are used for desserts, often with a large amount of sugar).
When it comes out of the oven, a soufflé should be puffed up and fluffy, and it will generally fall after 5 or 10 minutes (as risen dough does).