THE NUTRITIONAL VALUE OF
VEGETABLES AND FRUITS
The nutrition teacher or research worker usually groups foods into major categories in order to simplify teaching or the presentation of research data. The groups most frequently used for this purpose are: milk; meat, poultry, fish; eggs; beans (except snap beans), peas, and nuts; leafy, green, and yellow vegetables; tomatoes and citrus fruit; dried fruit; other fruits and vegetables; bread and cereal products; potatoes; fats; sugar.
It is noted that six of these twelve groups include vegetables and fruits. The chief nutritional contributions of these groups may be summarized as given below, and the specific content of the more common vegetables and fruits, according to the most recent tables of analyses, are given immediately after the descriptive paragraphs, This is further followed by lists of the mineral and vitamin contributions of the vegetables more commonly raised in the home garden; the latter lists are arranged in descending order of content of the particular mineral or vitamin mentioned.
Beans (not including snap beans, which are included with the leafy, green, and yellow vegetables) and peas are legumes which are high in protein value, although their proteins are not regarded as having sufficient amounts of the amino acids required by the human body, and should, therefore, not be used as the sole source of protein foods. They are of high caloric value and they make some contributions to the mineral and vitamin content of the dietary. Peas are relatively high in vitamin A content, which is associated with many physiological functions, notably growth and dark adaptation. Both beans and peas, particularly soy beans, are good sources of vitamin B1, which is the anti-neuritic vitamin enjoying such wide attention at the present time.
Nuts are grouped with beans and peas because they, too, are good sources of vegetable protein.
Leafy, green, and yellow vegetables include such a wide variety of foods as asparagus, broccoli, celery, Swiss chard, endive, collards, yellow sweet corn, beet, dandelion, mustard, and turnip greens, kale, lettuce, parsley, snap beans, spinach, and water cress. Vitamin A is one of the chief ingredients of these foods, although the quantity present varies widely from one food to another. Other nutrients contained in the foods of this category usually range rather generally throughout the list of nutrient factors. The leafy vegetables, particularly, supply a wide variety of nutrients. In fact, the leaves of plants are unique in being a complete food, by virtue of their biological function of serving as the seat for the synthesis of the proteins, carbohydrates, fats, and other nutrient constituents of the plant.
