TABLE III—FRUITS
| Food Materials | Water Per Cent | Protein Per Cent | Ether Extract Per Cent | Carbohydrates Per Cent | Ash Per Cent | Cellulose Per Cent | Acids Per Cent | |
| Acid: | ||||||||
| Apples | 82.50 | 0.40 | 0.5 | 12.5 | 0.4 | 2.7 | 1.0 | |
| Apricots | 85.00 | 1.10 | 0.6 | 12.4 | 0.5 | 3.1 | 1.0 | |
| Peaches | 88.80 | 0.50 | 0.2 | 5.8 | 0.6 | 3.4 | 0.7 | |
| Plums | 78.40 | 1.00 | 0.2 | 14.8 | 0.5 | 4.3 | 1.0 | |
| Cherries | 84.00 | 0.80 | 0.8 | 10.0 | 0.6 | 3.8 | 1.0 | |
| Gooseberries | 86.00 | 0.40 | 0.8 | 8.9 | 0.5 | 2.7 | 1.5 | |
| Currants | 85.20 | 0.40 | 0.8 | 7.9 | 0.5 | 4.6 | 1.4 | |
| Strawberries | 89.10 | 1.00 | 0.5 | 6.3 | 0.7 | 2.2 | 1.0 | |
| Whortleberries | 76.30 | 0.70 | 3.0 | 5.8 | 0.4 | 12.2 | 1.6 | |
| Cranberries | 86.50 | 0.50 | 0.7 | 3.9 | 0.2 | 6.2 | 2.2 | |
| Oranges | 86.70 | 0.90 | 0.6 | 8.7 | 0.6 | 1.5 | 1.8 | |
| Lemons | 89.30 | 1.00 | 0.9 | 8.3 | 0.5 | 1.5 | 1.8 | |
| Pineapples | 89.30 | 0.04 | 0.3 | 9.7 | 0.3 | 1.5 | 7.0 | |
| Pears | 83.90 | 0.40 | 0.6 | 11.5 | 0.4 | 3.1 | 0.1 | |
| Blackberries | 88.90 | 0.90 | 2.1 | 2.3 | 0.6 | 5.2 | 1.6 | |
| Raspberries | 84.40 | 1.00 | 2.1 | 5.2 | 0.6 | 7.4 | 1.4 | |
| Mulberries | 84.70 | 0.30 | 0.7 | 11.4 | 0.6 | 0.9 | 1.8 | |
| Grapes | 79.00 | 1.00 | 1.0 | 15.5 | 0.5 | 2.5 | 0.5 | |
| Watermelons | 92.90 | 0.30 | 0.1 | 6.5 | 0.2 | 1.0 | 0.5 | |
| Bananas | 74.00 | 1.50 | 0.7 | 22.9 | 0.9 | 0.2 | 0.5 | |
| Sweet: | ||||||||
| Dates, dried | 2.08 | 4.40 | 2.1 | 65.1 | 1.5 | 5.5 | 7.0 | |
| Figs, dried | 2.00 | 5.50 | 0.9 | 62.8 | 2.3 | 7.3 | 1.2 | |
| Prunes, dried | 2.64 | 2.40 | 0.8 | 66.2 | 1.5 | 7.3 | 2.7 | |
| Raisins | 10.60 | 2.50 | 4.7 | 74.7 | 3.1 | 1.7 | 2.7 | |
Care should be exercised in selecting ripe fruits and those which have not started to decay. The difficulty with so many fruits, which must be shipped from a distance, is, that, in order to reach their destination in fair condition, outwardly, they are picked before ripe and there is too much tannic acid in them. When fruits are allowed to ripen on the trees, the tannic acid is changed to sugar and fruit juices. One test of a ripened apple is to cut it with a steel knife—if the blade turns black, or if the cut surface of the apple turns brown in a few minutes, it should not be eaten, for it indicates an excess of tannin. It is this tannin which gives the small boy, with his green apples, excruciating pains. It will be recalled that the tannin from the bark of trees, so toughens the elastic skin of animals that we can wear this skin for shoes. The effect upon the live skin of the stomach and intestines, from the tannin in food, is not pronounced in toughening the skin, because of the activity and resistance of live matter.
Bananas are commonly picked green, because they decay so quickly that if they were picked ripe they would spoil before reaching the northern markets. The above table shows that bananas contain nearly twenty-three per cent of carbohydrates, which, in an immature state, are largely starches. The natural ripening process changes the starch to sugar, thus making them more easily digested. The starch globules, when not matured on the tree, are not easily broken and are thus difficult of digestion. Baking breaks the globules; a baked banana is thus more readily digested.
Nitrogenous Foods
As previously stated, in a mixed diet meat and eggs are the chief sources of nitrogenous foods. Next to these come the legumes.
Meat
Meat is almost all digested in the stomach by the gastric juice, which changes it into peptone. It is needless to say that it should be thoroughly masticated that there may be no delay in the prompt action of the gastric juice upon it. If any part passes into the intestine undigested, the process is continued by the trypsin of the pancreatic juice. The peptone is absorbed as peptone and after it passes through the inner coating of the intestines, it is changed back to protein and carried by the blood and lymph to all tissues of the body, where it is used for growth and repairs. As stated, any excess of protein above that needed for growth and repair, is oxidized in the blood, yielding energy and heat, and the waste is eliminated through the kidneys and the bile. The red blood corpuscles, which are nitrogenous, are broken down in the liver and discharged through the bile.
TABLE IV—ANIMAL FOODS