A. Coffee is an infusion or percolation of the coffee bean, composed of soluble constituents of the bean. The most essential constituents are the stimulating portion (the caffeine) and the volatile oils which give the characteristic odor and flavor. There is also some tannin present, the amount depending upon the method of preparation. For those who like the flavor of coffee, but find its stimulating action liarmful, there are decaffeinized coffees on the market. From these the caffeine has been almost completely removed by special com- mercial processes. B. Tea is an infusion of the leaf of the tea plant and contains a stimulant (theine), which is the same as caffeine in coffee, and also volatile flavoring substances and tannin. The grade of tea depends upon the kind of leaf used, the most desirable tea, known as flowery pekoe, being nuide from the youngest bud leaves on the twig; the next grade, orange pekoa, being the leaves next to the bud; and so on. Green tea is made from the tea leaves, steamed and dried. Black tea has passed through a process of fermentation which changes its taste and color, Coiiiixiraiivc compoaitioii of grccii and black teas. Kind. Thcinc. Tiumlc acid. Green Per cent. 1.7 2.3 Per cent. 16.8 Black 15.2 C. Chocolate and cocoa are beverages prepared by the addition of these materials to a liquid, so that the composition of the beverage is a composite of the composition of the two. When milk is used as the liquid, the food value of the beverage is materially increased. Chocolate and cocoa are preparations made from the ground cocoa bean, the principal difference in composition being that chocolate retains a large amount of fat, while approximately one-half the fat is removed from cocoa. There is a small amount of a stimulant (theobromine) in both. The chemical composition is as follows: [From "Food Products/' by Sherman.] Material. Water. Protein. Fat. Carbo- hydrate. Ash. Calories per pound. Per cent. 4.6 5.9 Per cent. 21.6 12.9 Per cent. 28.9 48.7 Per cent. 37.7 30.3 Per cent. 7.2 2.2 2 256 2 772 USE AND PREPARATION OF FOOD. 29 2. Use in the diet: A. Coffee and tea have no food vahie in themselves, but any food value must come from the sugar and cream which are served with them. They are used in the diet — (1) As a stimuhint. (2) To furnish flavor. B. Chocolate and cocoa are used — (1) For food value. (2) To furnish flavor. C. Danger of depending upon a stimulant. — Coffee and tea are both nerve stimulants which people may easily learn to depend upon and use to the exclusion of other things. They should never be allowed to take the place of articles with real food value. D. Coffee and tea should never be given to children. They fur- nish an undesirable stimulant and are liable to be used in place of essential foods, such as milk. E. Food value depends upon sugar and cream added. 8. Points to be considered in the preparation of coffee : A. Infusion or percolation. — (1) The aim should be to extract the soluble flavoring con- stituents wdth the smallest percentage of caffeine and tannin. (2) The flavor is volatile; therefore, long cooking at boiling point should be avoided. (3) Extraction at a low temperature removes a larger pro- portion of undesirable ingredients, hence should be avoided.

AI-modernized reading of the original text

A. Coffee is an infusion or percolation of the coffee bean, composed of soluble constituents of the bean. The most essential constituents are the stimulating portion (the caffeine) and the volatile oils which give the characteristic odor and flavor. There is also some tannin present, the amount depending upon the method of preparation. For those who like the flavor of coffee, but find its stimulating action harmful, there are decaffeinized coffees on the market. From these the caffeine has been almost completely removed by special commercial processes. B. Tea is an infusion of the leaf of the tea plant and contains a stimulant (theine), which is the same as caffeine in coffee, and also volatile flavoring substances and tannin. The grade of tea depends upon the kind of leaf used, the most desirable tea, known as flowery pekoe, being made from the youngest bud leaves on the twig; the next grade, orange pekoe, being the leaves next to the bud; and so on. Green tea is made from the tea leaves, steamed and dried. Black tea has passed through a process of fermentation which changes its taste and color, Comparative composition of green and black teas. Kind. Theine. Tannic acid. Green Per cent. 1.7 2.3 Per cent. 16.8 Black 15.2 C. Chocolate and cocoa are beverages prepared by the addition of these materials to a liquid, so that the composition of the beverage is a composite of the composition of the two. When milk is used as the liquid, the food value of the beverage is materially increased. Chocolate and cocoa are preparations made from the ground cocoa bean, the principal difference in composition being that chocolate retains a large amount of fat, while approximately one-half the fat is removed from cocoa. There is a small amount of a stimulant (theobromine) in both. The chemical composition is as follows: [From "Food Products/' by Sherman.] Material. Water. Protein. Fat. Carbohydrate. Ash. Calories per pound. Per cent. 4.6 5.9 Per cent. 21.6 12.9 Per cent. 28.9 48.7 Per cent. 37.7 30.3 Per cent. 7.2 2.2 2 256 2 772 2. Use in the diet: A. Coffee and tea have no food value in themselves, but any food value must come from the sugar and cream which are served with them. They are used in the diet — (1) As a stimulant. (2) To furnish flavor. B. Chocolate and cocoa are used — (1) For food value. (2) To furnish flavor. C. Danger of depending upon a stimulant. — Coffee and tea are both nerve stimulants which people may easily learn to depend upon and use to the exclusion of other things. They should never be allowed to take the place of articles with real food value. D. Coffee and tea should never be given to children. They furnish an undesirable stimulant and are liable to be used in place of essential foods, such as milk. E. Food value depends upon sugar and cream added. 8. Points to be considered in the preparation of coffee : A. Infusion or percolation. — (1) The aim should be to extract the soluble flavoring constituents with the smallest percentage of caffeine and tannin. (2) The flavor is volatile; therefore, long cooking at boiling point should be avoided. (3) Extraction at a low temperature removes a larger proportion of undesirable ingredients, hence should be avoided.

Use and preparation of food