Tubers, Husk Vegetables, And Vegetable Fruits
( Originally Published 1913 )
Although the varieties of vegetables described under this head do not as a general thing possess the same curative properties as those treated in the previous chapter, they are, on the other hand, more nutritious, owing to their greater starch content. The assimilation products absorbed from the air by the leaves are deposited in the root tubers in the form of starch, and it is just these products which we shall now discuss as food. The tuberous roots most rich in starch, such as the tropical varieties and the potatoes, have already been described. We shall now consider the turnips and other tubers of this class.
The turnips most frequently used are no doubt the yellow turnips. They contain in the natural substance, according to König, 1.18 per cent. proteins, 0.12 per cent. fat, 4.03 per cent. of sugar, with 3 per cent. of other carbohydrates and 1.62 per cent. of cellulose. In the dry substance they contain 8.91 per cent. of protein, 68.48 per cent. of carbohydrate, and 1.43 per cent. nitrogen.
Of nutrient salts the yellow turnip, contains much lime 11.34 per cent.—and 36.93 per cent. potash, 21.17 per cent. soda, 1.01 per cent. iron, o.45 per cent. sulphur; thus, there is much potash and soda in addition to the considerable amount of lime.
While their high content of certain salts would lead us to consider yellow turnips as a useful vegetable, they are unfortunately not well assimilated by the intestine, as Rubner states that a considerable portion of the nutritive substance is eliminated unused. The yellow turnip promotes the action of the bowels. The "red turnip"-the beet-is principally used as a salad. According to Kong, i, p. 772, it contains 0.54 per cent. of sugar and 9.02 per cent. o,f other carbohydrates ; those gathered in the beginning of August contain 1.37 per cent. of protein, and beets in general contain 1.05 per cent. of cellulose.
A variety of turnip which is not much used, although deserving o,f more attention, is the white turnip. It probably contains the most water of any : 93 to 95 per cent. It is quite rich in nutrient salts, 45 per cent. potash and 10.60 per cent. lime, but, owing to its indigestibility and poor assimilation, quite a good deal of these salts is lost. The digestibility and general value of white turnips may be increased by salting them and allowing them to ferment, as is also, done with the white cabbage. When cooked they may be mixed with sour milk or cream, and also with tomato sauce. Like the yellow turnips, they likewise have a favorable action upon the bowels.
Kohlrabi is much more used than white turnips. This variety of turnip has a sweetish taste, but does not contain very much sugar, only 0.38 per cent., with 7.80 per cent. of carbohydrates, o,f which a certain amount, owing to its chemical composition and poor assimilation, need not be taken into account. Kohlrabi contains 1.68 per cent, of cellulose, rather more than does white cabbage, and, while the total carbohydrate content amounts to 8.47 per cent., only 6.87 per cent. is assimilated. Very nearly one-half this amount is fruit-sugar, which is well tolerated by many diabetics. For this reason kohlrabi may be recommended in diabetes. What is here said of the kohlrabi is applicable to many other vegetables.
Less as a vegetable, but more as a stimulant for the appetite, the large radishes—both black and white—have come into use. They do excite the appetite, but are of themselves very indigestible. They should consequently not be used by persons having weak stomachs. For healthy persons with good stomachs they are an excellent food at the beginning of a meal, especially the smaller and more tender radishes.
Horseradish is rather to be regarded as a pungent flavoring substance than as a vegetable, which should only be used by perfectly healthy persons as a stimulant for the appetite in combination with other foods. Even healthy persons would do well to use it but sparingly. Like the onion, the horse-radish should only be used to improve the taste of certain foods. Both of these vegetables may have an injurious action upon the kidneys owing to the pungent substances they contain.
The various radishes contain a pungent substance, an ethereal oil similar to that contained in mustard. The smaller varieties of radishes are more easily digested than the larger ones, but when not well masticated and salivated will cause disagreeable eructations. In summer the large radish will be found useful when the appetite may for various reasons not be quite up to the mark. It should first be well salted, which will draw out some of its fluid content, and should then be left covered up for a time until more juice has been extracted. In this way the fibers are somewhat softened, and are rendered more digestible. People possessed of a good stomach can eat quite a good deal of it at the beginning of a meal, and yet have plenty of appetite for the rest of the food. It is not without nutritive qualities, since it contains 8.47 per cent. of carbohydrate, but there is a large amount of fiber, so only 7 per cent. o,f the carbohydrate is assimilated. Small quantities may be taken by diabetics, but the smaller varieties, which contain only 3.79 per cent. of carbohydrates, would be better; of these, but 3. 18 per cent. is assimilated.
The tomato, with its pleasant acid taste,—the name tomato comes from the Aztec (Mexico) word tomatl,—is another agreeable addition to various other foods. It also has a certain nutritive value, since, according to Bailey and Lodema, it contains 4 to 5 per cent. of sugar. In this country it is principally the juice which is used; it is put up in bottles in the summer, and is then used throughout the year, to flavor other foods, such as rice, potatoes, cabbage, etc. When a considerable quantity of tomato is used the nutritive properties are naturally improved. Owing to its content in citric and malonic acid,-O.7 to o.8 per cent.,—the tomato may be regarded as a healthful food.
In some countries, and particularly in England, America, Spain, and Italy, this vegetable is also eaten raw as a salad. The meat is tender, and when this alone is eaten it is easily digested; when the seeds are also used they may have a some-what beneficial action, as do figs, by exercising a sort of massage upon the intestinal mucous membrane. As a disadvantageous feature it may be mentioned that tomato contains a small quantity of oxalic acid.
When prepared as an acid vegetable the cucumber may also prove useful. In general, it is not easily digested, but when it undergoes a process of fermentation in salt water its tissues are softened by the action of the lactic acid which is thus formed, so that it becomes somewhat more digestible. The salted cucumber pickle would therefore probably be the most healthful mode of using the cucumber, except in the cases in which salt is to be avoided, as in kidney affections.
The cucumber is not rich in nutritive substances. It con-tains only 1.09 per cent. of protein, but the carbohydrates are rather better represented, there being 1.12 per cent. of sugar and 1.09 per cent. of other carbohydrates. Large cucumbers contain more sugar and are therefore better adapted for pre-serving. According to König, the nutrient salt content of the cucumber is in the ash 51.71 per cent. of potash, 4.19 per cent soda, 6.97 per cent. of lime, 0.75 per cent. iron, 13.10 per cent. phosphorus, and a considerable amount of chlorine, 9.16 per cent.
The pumpkin is likewise prepared as a sour vegetable in some countries, as in Hungary. It is also used like cabbage in combination with various dishes prepared from, flour, such as the "strudel." In my opinion, this vegetable is undeservedly neglected as a food, for it contains a considerable quantity of nutritive substance. It only contains 1.10 per cent. of protein, but over 6 per cent. of carbohydrate, of which 1.29 per cent. is in the form of sugar, and 5.16 per cent. in other carbohydrates. The small pumpkin is worthy of much greater attention than is accorded it at present, since it contains as much as 6 per cent. of sugar (4 per cent. grape-sugar and 1.50 per cent. cane-sugar). It is therefore a nutritious vegetable, and its taste is very agreeable. Of the nutrient salts it contains much phosphorus, up to 33 per cent. in the ash, and much soda and lime, 21.13 and 7.79 per cent. ; it is very poor in common salt.
The melon is much more used and liked than the pumpkin, although some varieties of the former are less nutritious than the dried pumpkin. According to König, the melon contains 0.84 per cent. protein, 3.41 per cent. sugar, and up to 3 per cent. of other carbohydrates; the American sugarmelon con-tains 8 to 12 per cent, of sugar, together with the other carbohydrates.' The watermelon has o.61 per cent. of protein, 4.21 per cent.. sugar, and 1.07 per cent. of other carbohydrates. When we drink melon juice we absorb 4.14 per cent. of invert-sugar and o.17 to o.19 per ct. of malic acid. Notwithstanding the fact that the cellulose content of the melon is not great,—1.06 per cent.,—it is nevertheless hard to digest, as is also the pumpkin, especially when not quite ripe. Both of them, have laxative properties, but they may also have an irritating effect on the intestine, thus causing diarrhea and intestinal catarrh. The juice of the watermelon is very refreshing in the heat of summer, and in some countries, as in Turkey, Spain, and Hungary, this fruit is much eaten. The negroes in the United States are particularly fond of watermelon. When there is catarrh of the intestine or a tendency to diarrhea melon is a dangerous food, and when cholera is prevalent the people are warned against its use.
To a much greater extent than the above-named vegetables, green peas form a nourishing, and also a very palatable, food. They contain (according to König, i, p. 781) 9.50 per cent. of sugar and other carbohydrates and 5.54 per cent. of nitrogen, with 1.61 per cent. of cellulose. Green peas should be classed among the most nutritious and most easily digested vegetables, especially when they are young and tender; they contain but little cellulose. When they are older they are more nourishing, but also contain more of the latter substance, and are digested with more difficulty, both in the stomach and intestine. Peas should not be given to small children, who, as I have frequently observed, simply swallow them whole, in which form they are also passed out through the intestine, after having caused irritation of the latter. The garden variety of green peas may contain as much as 62.45 per cent. of sugar and other carbohydrates, of which only 10.40 per cent. is assimilated.
String beans are less nourishing and more indigestible. They consist principally of inosite, and, as this substance does not increase the sugar in the urine in diabetes, string beans represent one of the most desirable among the green vegetables for patients suffering from that disease. Of the 6.60 per cent. of carbohydrates only about 5.54 per cent. is assimilated. Green string beans contain much less sugar than peas, only about 1.16 per cent.