( Originally Published Early 1900's )
The group of carbohydrates is divided into starches and sugars. The starches are found in fruits and vegetables, while an animal starch known as glycogen is found in liver.
Starch may be separated from different food stuffs, such as wheat, corn, and potatoes. Pure starch is a fine, glistening, white powder, seen in the form of cornstarch used for puddings and in laundry starch. Pure starch contains water and carbon.
How can we tell whether or not starch is present in a food? (See Experiment I, page 43.) What does starch give the body? Let us see if we can separate starch from the other materials in potatoes or cereals.
EXPERIMENT I. Grate a pared potato, and squeeze the pulp into a piece of cheesecloth held over a bowl, letting the juice settle. Then drain off the liquid, add a little water to the sediment, and boil. Test for starch. Examine the pulp left in the cloth-it contains much cellulose.
EXPERIMENT II. Rub a teaspoonful of oatmeal in half a cup of cold water for several minutes. Pour through a sieve. Boil the water and test for starch.
EXPERIMENT III. Put the thinnest slice of raw potato you can cut under the microscope and note the appearance of the starch cells. Examine also cornstarch, laundry starch, and rice starch. Make drawings.
EXPERIMENT IV. Rub to a paste one teaspoonful of cornstarch mixed with a tablespoonful of cold water. Add one-half cup of boiling water. Stir constantly and bring to the boiling point. Stir until it thickens, and note thickness.
EXPERIMENT V. Stir one teaspoonful of cornstarch into one-half cup of boiling water and note the result. Break open one of the lumps formed. What is the condition of the starch inside the lump? Repeat this experiment, using flour.
EXPERIMENT VI. Mix together one teaspoonful of sugar and one of cornstarch. Pour over the mixture one-half cup of boiling water, stirring all the time. Does it lump? Why, (See Cornstarch Pudding, page 252.) Why do we use cornstarch or flour in sauces?
EXPERIMENT VII. Brown a little cornstarch or flour in the oven: Then repeat Experiment IV, substituting one teaspoonful of the browned starch for the raw cornstarch, and note thickness. Repeat, using browned flour. Compare the thickness of the mixture in Experiment IV with the one thickened with browned starch or flour. What effect has browning on flour or starch? If browned flour is substituted for raw flour in a sauce or gravy would more or less be used?
EXPERIMENT VIII. Cut a very thin slice from a washed and pared potato. Put it into a cup, and let water run over it for fifteen minutes. Then pour diluted iodine over it. Treat an unwashed, slice in the same way and compare the colors of the two. Cook soaked and unwashed slices in different saucepans. Cover with the iodine solution and note the color. What food element is removed by soaking?
EFFECT OF COOKING ON STARCHES
Moist heat causes the starch grains to swell so that the coating of cellulose is broken and softened. After being softened and swollen, the starch is said to be gelatinized. This may take place below -the boiling point but most starches are more thoroughly cooked by high temperatures. Raw starches cause much digestive trouble. Cook all starches thoroughly.
Dry heat changes starch to dextrin, a form of sugar that is very soluble. This change takes place in the crust of bread, and for this reason the crust is more digestible than the center portion of a loaf.
Starch and flour (which is largely starch) are much used for the thickening or binding together of other foods, for example, gravies, sauces, and cream soups. In making white sauces, the chief end is to secure a smooth mixture without lumps, free from any gluey appearance and perfectly blended with the fat used. Sauces made by adding the flour to hot fat are not easily digested because the fat is overheated and each starch grain is coated with fat.
THE MAKING OF WHITE SAUCE
(Each group of two pupils is to use one-half of recipe.)
TABLE FOR WHITE SAUCE
KIND BUTTER FLOUR MILE USE
No. 1 1 tbsp. 1 tbsp. 1 c. soups
No. 2 2 tbsp. 2 tbsp. 1 c. vegetables
No, 3 2 tbsp. 4 tbsp. 1 e. Screamed dishes t croquettes
EXPERIMENT IX. (For older pupils.) Repeat Experiment IV, using quantities given in table. Compare results. Repeat Experiment IX, using browned flour. How much browned flour would be needed to thicken sauce No. 2? Would this be a desirable consistency for sauces?
Reserve as much cold milk as there is flour to be added to the sauce. Scald the remainder of the milk. (See Cocoa, page 81.) Rub the cold milk with the flour until it makes a smooth paste. Add to it the scalded milk, stirring all the time. Return it to the double boiler and cook for fifteen minutes. Continue stirring until it thickens, then stir only occasionally. Add the salt and butter when ready to serve the sauce. It may be kept for half an hour or longer over hot water.
EXPERIMENT X. Thickening Power of Starches. (For older pupils.) Repeat Experiment IV, using cornstarch, also flour. Compare thickening power. Why do they differ?
EXPERIMENT XI. Let different groups add 1, 1 1/2, and 2 tbsp. of corn-starch to boiling water, as in Experiment IV. When cold, note consistency. What is the proportion of starch in the pudding recipe? In Lemon Sauce? Why is a large quantity of cornstarch objectionable? How much cornstarch equals one egg in thickening power?
QUESTIONS AND PROBLEMS
Into what groups are carbohydrates divided? Of what use to the body is starch? What foods are rich in starch? What is the proportion of carbohydrates in your diet? What part of this is starch? Tell what you can of the digestion of starch. Why does cooking thicken a starch mixture? Why is cooked starch easier to digest than raw starch? Why should cereals be allowed to come to the boiling point before being put in the double boiler? How does dry heat affect starchy foods? Why is the crust of bread easily digested? What is meant by sauce? What is the appearance of a good white sauce? For what is it used? 'fell how to make white sauce. What are the proportions for a thin sauce? A medium sauce? For what could each be used? What is the proportion of thickening in thick sauce? What is the best proportion of cornstarch to liquid for puddings?
Grains or cereals form a large part of our food. Bring samples of whole grains of wheat, rice, and corn. Compare their composition. Which class of food is abundant in all of them? Which cereal has the most protein? Fat?
In preparing most cereals for food the outer hull is removed and they are then cracked, crushed, or rolled ; a few of them are used whole. Rice is an example of this. All cereals have a tough skin called cellulose that covers the starch grains. When cornmeal is sifted some cellulose is found in the sieve. This skin is very tough in corn; therefore mush, grits, and hominy need long cooking. Cereals are starchy foods, and therefore must be well cooked. Thorough cooking in boiling water also develops the flavor. If cereals are not well cooked they have a raw taste.
Serving Cereals. In warm weather rice and fine wheat preparations are the most suitable cereals to use as they are not rich in fat. In cold weather oatmeal, cracked wheat, corn-meal, grits, and hominy also are good. Cereals are served with milk or cream because the combination furnishes the food which our bodies require. Sugar is not needed, as cereals are largely composed of starch, which serves the same function in our bodies as sugar. If children have formed the habit of eating sugar on their cereals encourage them to use very little. Sprinkle it on with a sugar shaker.
Do not serve any sour fruits with cereals, even if you have sweetened them well, as acids interfere , with the digestion of starches. Take a mouthful of dry toast now and then when you are eating cereals so that you will chew more carefully.
The Ready-to-Serve Cereals. In some ready-to-serve cereals only a part of the original grain is used, and their food value cannot be found except by chemical analysis. These preparations are usually more expensive than the cereals cooked at home. Compare cost and food value of a serving of a ready prepared cereal and of one cooked at home.
Steam Cooked Cereals. Rolled oats and wheat, and the fine wheat preparations have been steamed at the factory and do not need such long cooking as cornmeal, grits, and other raw grains.
Keeping Cereals. Pour cereals into glass jars and keep tightly covered in a cool place. Cereals containing fat grow rancid or musty in warm weather or when kept in a warm place. Test by smelling. If musty they are not fit for food. If a cereal has insects or little webbed balls in it do not use it, as the balls contain the eggs of insects.
COOKING CEREALS IN THE DOUBLE BOILER
Measure the required amount of water. Put it into the upper kettle of the double boiler and place it directly over the fire. When it boils add the salt. Then sprinkle in the cereal a little at a time, so as not to stop the boiling. Stir briskly all the time, so that each little grain is kept by itself. If lumps form, the grains on the inside cannot swell and burst with the heat and will not be fit for food. The starch grains swell when heated just as popcorn does. Cereals must be added slowly to boiling water and cooked rapidly at first, then gently. If the cereal is about to run over, lower the heat or raise the pan from the flame. Do not strike the edge of the kettle sharply with your spoon as the metal will be dented or, if of enameled ware, chips will fall into the food.
Putting the Cereal to Steam. Boil cereal over the flame for five or ten minutes, according to the quantity; then add sweet, dried fruit if desired. Wipe the inside of the top part of the kettle, and smooth the cereal with a spoon. Cover and set the kettle over the lower part of the boiler and steam according to time given in the table. Put the lower kettle on to heat when you start the cereal to cooking. Fill it one-third full of water. Watch the lower kettle and add more boiling water if it is in danger of boiling dry. When the cereal is removed, fill the kettle with cold water so that it may be easily cleaned. Cook all steamed cereals by this method.
COOKING CEREALS DIRECTLY OVER THE FIRE
Cornmeal, grits, coarse hominy, boiled rice, etc., should be cooked directly over the fire. Use a thick saucepan, and proceed as for steamed cereals, pushing the vessel to the back of the range, or lowering the heat instead of steaming over water.
Cooking Cereals in Fireless Cooker.. Cover closely and cook over the flame as directed. When it is boiling briskly, put cereal on a very hot radiator in the fireless cooker.
USING LEFT-OVER CEREALS
If any cereal is left from a meal, put it away carefully in a cool place, as it sours quickly; in hot weather keep in the ice-box. While still warm pour it into custard cups that have been dipped in cold water, filling each cup half full. When you are ready to serve, turn it into a cereal bowl. If you wish it warmed, turn it into a smooth pan, cover and put it into the oven or steam for about twenty minutes, and then lift with a spatula to the cereal bowls.
Turn grits, or any of the fine wheat preparations, or mush, while warm, into an enameled pan that has been dipped in cold water. When ready to serve, cut it into squares, dip into egg and crumbs, and place on well greased tins in a hot oven for fifteen minutes. Leave until it becomes a golden brown. Serve hot with meats or for breakfast with brown sugar or maple syrup.
Dipping into Eggs and Crumbs. Beat together one egg and two table-spoonfuls of cold water until well mixed. Dip the squares of cereal into flour, then into the egg, and then into fine cracker or bread crumbs. The cereal must be well coated with crumbs, but if too many are put on they will fall off and burn in the pan.