Foods and home making

What is protein ? How much is there in cereals ? There is an old saying : “ Bread is the staff of life.” Perhaps bread was thought to be such an important food because grains from which breads are made contain a substance which may build the body. This body-building material found in cereals is called protein. Protein may be a new word to you. Remember it is a material found in grains (and other foods about which we shall learn later) which builds the body. Most grains contain from 10 to 12% protein. Oatmeal contains over 15%. There are many kinds of proteins. Some are of better quality than others. The proteins in cereals are of intermediate quality. Why do cereals thicken when cooked? You will remember that when you cooked a breakfast cereal, it appeared to swell, absorbed the water you had added, and became pasty. This was due in part to the fact that the cereal contained starch. Let us again observe how starch acts when it is cooked in water. We shall experiment with cornstarch. Cornstarch, as the name indicates, is prepared from corn. Corn, like all grains, contains starch. When the starch is extracted from the other materials in the grain, we call it cornstarch. If the starch were removed from wheat, we should call it wheat starch. While the starches found in grains differ in certain respects, they have many properties that are alike. Experiment 6 '.To show how starch acts when heated in water. (a) In a small saucepan or enamel custard cup, put 1 teaspoon of cornstarch and \ cup of cold water. Mix well and set aside for a few minutes. Does the starch settle to the bottom of the pan? Is starch soluble in cold water? How do you know? 59 Buying and Cooking Cereals (b) Stir again and heat the mixture until it becomes thick. With a spoon take out a small quantity of the material. Then feel of it between your thumb and first finger. How does the mixture feel ? (c) Note how thick or stiff the mixture is. Then set aside to cool. The cooling may be hastened by placing the utensil holding the starch mixture in cold water. When the mixture is cold, note how stiff it is. How does the stiffness of the cold and hot mixture compare? Figure 23. The Composition of a Wheat Grain Note that wheat contains water. Does it seem strange that a dry sub- stance like wheat contains water ? The chemist finds water in all foods. Wheat contains proteins — the body-building substances. Are you surprised that wheat contains fat? We think of greasy-feeling foods like butter and bacon as containing much fat. Many foods which dc not feel greasy contain a small quantity of fat. Note that wheat is about three fourths carbohydrates. This term may seem new to you, but you already know three substances which it embraces. When you come across this word in studying about foods, remember that it is a term including sugar, starch, cellulose, and similar materials. Wheat contains ash. Ash is another name for mineral matter. Mineral matter is often called ash because the ashes left when a food burns are mineral matter. There is much starch in cereals. Many of the uncooked cereals are about two thirds starch. What is the percentage composition of food? We have 6o Breakfast learned that cereals contain cellulose, proteins, and starch. Do cereals contain anything else? Look at Figure 23.