Grains are dry. So therefore are the flours made from them. These contain relatively little water. Wheat flour of good quality takes up water to about two thirds its own weight. Starch is the substance of which there is most in flour. It forms about three fourths of the weight of flour. This makes flour-mixtures heat-giving and energy foods. Protein, the tissue-building substance in food, is present in flours in larger quantity than in most plant foods. There is approximately P 10% - W 10% - F 1-2% - MM 1-2%. That amount of fat is large for plant foods. Animal foods contain much more. The mineral salts are present in relatively high proportion, but, as noted, are not always fully available to the body as they exist in grains and flours.

Gluten is the constituent that makes a moist mass of flour cohere as it expands when heated.

Comparison Of The Composition Of Different Flours

Wheat flour that is not creamy-white is usually inferior. Pastry-flour is wheat flour with the gluten largely removed.

It is mainly starch. It makes more delicate mixtures. Macaroni flour is also from wheat. It has more gluten than is usual in wheat bread-flour. Macaroni is used as a vegetable. Corn meal and rice both lack gluten. When used in breads they need to be mixed with flour to be cohesive. Alone they are friable and crumble. Use as vegetables too.