英文科學(xué)讀本 第五冊·Lesson 37 More about the Farinaceous Foods

Lesson 37 More about the Farinaceous Foods

You all know what this is, began Mr. Wilson, as he held the object before the boys at the opening of the next lesson.

Yes, sir; it is a cob, or ear, of corn.

Right; so it is, he replied. "Now I am going to start this morning with corn, as another of the farinaceous foods. But first of all, tell me why the name farinaceous is given to these foods."

Farinaceous comes from the Latin word farina, sir, which means flour, said Will. "All these foods are used in the form of fine meal or flour."

Quite right, replied Mr. Wilson. "Now let us pass on to consider this one—corn.

Corn is not grown in England— their summers are not long enough to ripen the grain. It is, however, grown largely in many parts of the world, and is an important article of food. Corn, like the other grains, consists mostly of starch. It contains only about 9 percent gluten, while wheat contains from 10 to 12, and oatmeal 16 percent. On the other hand, corn-meal is richer in fatty or oily matter than any of the other grains. This renders it easily digestible. In this country we not only grind the ripened corn into flour, and use it as we do other flours, but we cut the green cob before it is ripe and boil it for the table. In this state the corn upon the cob makes a most delicious and nutritive vegetable.

Because of its deficiency in gluten, it is customary to mix this corn-meal with an equal quantity of wheaten flour for making bread. We also use corn-meal for porridge, eating it with milk and sugar. It is commonly known as stirabout, mush, hasty pudding.

Nearly all the corn that finds its way to shipment abroad is in the form of corn-starch. It consists entirely of the starchy portion of the grain, and is used for making milk-puddings, blanc-manges, etc. To prepare this corn-starch, the kernels are first well soaked in water till they swell up and become rather soft. They are then crushed between rollers in a tank of water. As the crushing process goes on, the water becomes white and milky-looking. Don't forget the flour in the muslin bag, and you will know at once what goes on in that tank.

When the whole of the grain is crushed fine, the milky-looking liquid in the tank is made to pass through sieves, which hold back the pieces of husk and skin. You remember, of course, that in all the grains the gluten is invariably found adhering closely to the outer skin. When therefore these pieces of the skin are held back in the sieve, all the gluten is held back at the same time. The milky-looking liquid which passes through contains only the starch of the grain. It is made to flow into tanks, and there left to stand for a time, till all the starch has sunk to the bottom. The clear water is then drained off, and the starch is removed and dried over a gentle heat. This starch is the corn-starch, which we use with milk and eggs to make our puddings and custards.

Rice is another important farinaceous food. It forms the staple food of the people of the East. Rice is to them what bread is to us. It contains, however, a very small amount of tissue-forming matter—in fact, the least of all the corn-grains—not more than 6 or 7 per cent; while 75 per cent of the grain is starch. It is not, therefore, of much nutritive value unless used with some other food rich in flesh-forming and fatty matter. We use rice both whole and in the form of meal, but we always use it with such things as eggs and milk, or in soups.

Next among the farinaceous foods come sago, arrowroot, and tapioca, which are pure starches, and contain no gluten. These foods differ from the others of the class in that they are obtained not from the grain, but from the substance of the stems of the plants. It is no part of our present business to dwell upon the mode of preparation in either case. That was done in one of our earlier lessons. We have now only to arrange them in our list of starch-foods. Considered as food, they have little value, unless used with some tissue-forming and fatty substances; they are quite incapable of supporting life alone.