223. Adulteration of Chocolate and Cocoa.—The various chocolate and cocoa preparations offer an enticing field for sophistication; they are not, however, so extensively adulterated as before the enforcement of national and state pure food laws. The most common adulterants are starch, cocoa shells, and occasionally iron dioxid and other pigments to give color, also foreign fats to replace the fat removed and to give the required plasticity for molding.
224. Comparative Composition of Beverages.—Tea and coffee as beverages contain but little in the way of nutrients other than the cream and sugar used in them. The solid matter in tea and coffee infusions amounts to less than 1.2 per cent. When cocoa is made with milk, it is a beverage of high nutritive value due mainly to the milk.
Composition of Beverages[[56]]
| Kind of Beverage | Water | Protein | Fat | Carbohydrates | Fuel Value per Lb. |
|---|---|---|---|---|---|
| % | % | % | % | Cal. | |
| Commercial cereal coffee (0.5 ounce to 1 pint water) | 98.2 | 0.2 | — | 1.4 | 30 |
| Parched corn coffee (1.6 ounces to 1 pint water) | 99.5 | 0.2 | — | 0.5 | 13 |
| Oatmeal water (1 ounce to 1 pint water) | 99.7 | 0.3 | — | 0.3 | 11 |
| Coffee (1 ounce 1 pint water) | 98.9 | 0.2 | — | 0.7 | 16 |
| Tea (0.5 ounce to 1 pint water) | 99.5 | 0.2 | — | 0.6 | 15 |
| Cocoa (0.5 ounce to 1 pint milk) | 84.5 | 3.8 | 4.7 | 6.0 | 365 |
| Cocoa (0.5 ounce to 1 pint water) | 97.1 | 0.6 | 0.9 | 1.1 | 65 |
| Skimmed milk | 90.5 | 3.4 | 0.3 | 5.1 | 170 |
CHAPTER XV
THE DIGESTIBILITY OF FOODS
225. Digestibility, How Determined.—The term "digestibility," as applied to foods, is used in two ways: (1) meaning the thoroughness of the process, or the completeness with which the nutrients of the food are absorbed and used by the body, and (2) meaning the ease or comfort with which digestion is accomplished. Cheese is popularly termed indigestible, and rice digestible, when in reality the nutrients of cheese are more completely although more slowly digested than those of rice. In this work, unless otherwise stated, digestibility is applied to the completeness of the digestion process.
The digestibility of a food is ascertained by means of digestion experiments, in which all of the food consumed for a certain period, usually two to four days, is weighed and analyzed, and from the weight and composition is determined the amount, in pounds or grams, of each nutrient consumed.[[72]] In like manner the nutrients in the indigestible portion, or feces, are determined from the weight and composition of the feces. The indigestible nutrients in the feces are deducted from the total nutrients of the food, the difference being the amount digested, or oxidized in the body. When the food is digested, the various nutrients undergo complete or partial oxidation, with the formation of carbon dioxid gas, water, urea (CH4N2O), and other compounds. The feces consist mainly of the compounds which have escaped digestion. The various groups of compounds of foods do not all have the same digestibility; for example, the starch of potatoes is 92 per cent digestible, while the protein is only 72 per cent. The percentage amount of a nutrient that is digested is called the digestion coefficient.