Cooks who can't tell Emmenthal from Gruyere or quince from pomegranate might enjoy a new ingredients guide from Reader's Digest.

The 230-page book, ("Cook's Ingredients," Reader's Digest, 1990, $14.95) is filled with color pictures and illustrations of fruits, vegetables, cheeses, grains, beans, meats and game, fish and sausages.Accompanying the pictures are short texts explaining what the foods are, where they come from and how they are commonly used.

The book explains, for example, that while Emmenthal and Gruyere are both Swiss cheeses, Emmenthal is blander than Gruyere and gets stringy when cooked. Gruyere doesn't.

Pomegranate, a fruit available in autumn, is usually eaten raw. Quince, which is hard and acid, is mostly used in baking.