In Japan and Korea, buckwheat noodles, called soba, are a staple. Oat bran is the envelope of the groat, composed of the outermost pericarp. It is high in soluble fiber. Potato flour is sometimes called potato starch and is used in baking and as a thickener. It is made from cooked potatoes that have been dried and ground.
Rye flour is the finely ground flour obtained by sifting rye meal.
The dark and light varieties are interchangeable in recipes, but the dark does have a stronger flavor. Rye and wheat flours are the only flours containing gluten-forming proteins that are important in baked goods. Spelt is a grain that is native to southern Europe and has a subtle, almost hazelnut flavor. Soy flour has a strong flavor and must be combined with wheat flour when used in baking. It is ground from whole soybeans and sometimes called soy powder or soya.