School and Home Cooking

by Carlotta C. Greer

ENERGY; FUEL.—An automobile is a machine. The use of gasoline in this machine gives it energy or the power to move.

The human body is also a machine. Certain foods are taken into the human machine. The utilization of these foods gives the body energy or the power to move (i.e. to do work). The body is capable of both voluntary and involuntary work. Walking and running are examples of the former kind of work, while the beating of the heart and the circulating of the blood are examples of the latter kind.

At the same time that the body works, heat is generated. Hence foods not only give the body the power to do work, but incidentally they heat the body. Foods which enable the body to work are termed energy-giving or fuel foods.

There are a number of energy-giving or fuel foods: sugar is the first one to be considered.

EXPERIMENT 10: THE SOLUBILITY OF GRANULATED SUGAR IN COLD WATER—Place half a teaspoonful of granulated sugar in a test tube, add a little cold water, shake. Is the mixture clear? Set it aside for a few minutes. Does the sugar separate from the water?

EXPERIMENT 11: THE SOLUBILITY OF GRANULATED SUGAR IN HOT WATER.—Dissolve half a teaspoonful of granulated sugar in hot water. Compare with Experiment 10. Which dissolves sugar more readily,—cold or hot water? If you desired to dissolve some sugar quickly, at what temperature would you have the water?

EXPERIMENT 12: THE SOLUBILITY OF POWDERED SUGAR.—Dissolve half a teaspoonful of powdered sugar in the same quantity of hot water used in Experiment 11. Does it dissolve more readily than granulated sugar? Explain this difference. If you desired to dissolve some lumpy sugar quickly, how would you prepare it?

THE DIGESTION OF SUGAR.—Since sugar is so readily dissolved, and since dissolving is an important step in the process of digestion (see Solution and Digestion), it would seem that the digestion of sugar would be easy. Some sugars, such as glucose, need no digestion in a chemical sense, and are wholesome provided their solution is not too concentrated. The digestion of other sugar, such as granulated sugar, is slightly more complex.

Because the digesting of some sugar is simple, one should not conclude that this food should be used in large quantities or in preference to other fuel foods. If sugar is eaten in large quantities there is so much dissolved sugar for the organs of digestion to take care of that the stomach and small intestines become irritated. This is especially true when candy is eaten between meals,—at a time when the stomach is empty. Then, too, it may ferment in the stomach or intestines and produce digestive disturbances. All sweets should be eaten only in moderation and either during a meal or at its close. When sugar is mixed with other foods, it is diluted, and is not so apt to cause distress.

SUGARS AND SIRUPS.—In various plants and in milk, the chemist finds a number of different kinds of sugar. These may be classified into two groups:—(1) single sugars and (2) double sugars. Dextrose or glucose is one of the single sugars, while sucrose or cane sugar is an example of a double sugar.