Starch, as you have seen, will not dissolve in the cold water. Dry it, after the water is poured on, and minute grains remain. Look at these grains under a microscope, and each one is cased in a thick skin, which cold water can not dissolve. In boiling water, the skins crack, and the inside swells and becomes gummy. Long boiling is thus an essential for all starchy foods.
Bread proper is simply flour, water, and salt, mixed to a firm dough and baked. Such bread as this, Abram gave to his angelic guests, and at this day the Bedouin Arab bakes it on his heated stone. But bread, as we understand it, is always lightened by the addition of yeast or some form of baking-powder, yeast making the most wholesome as well as most palatable bread. Carbonic-acid gas is the active agent required; and yeast so acts upon the little starch-granules, which the microscope shows as forming the finest flour, that this gas is formed and evenly distributed through the whole dough. The process is slow, and in the action some of the natural sweetness of the flour is lost. In what is known as aërated bread, the gas made was forced directly into the dough, by means of a machine invented for the purpose; and a very scientific and very good bread it is. But it demands an apparatus not to be had save at great expense, and the older fashions give a sufficiently sweet and desirable bread.
Rye and Indian Corn form the next best-known varieties of flour in bread-making; but barley and oats are also used, and beans, pease, rice, chestnuts, in short, any farinaceous seed, or legume rich in starch, can fill the office.
Oatmeal may take rank as one of the best and most digestible forms of farinaceous food. Some twenty-eight per cent of the grain is husk, seventy-two being kernel; and this kernel forms a meal containing twelve parts of nitrogenous matter, sixty-three of carbo-hydrates, five and a half of fatty matter, three of saline, and fifteen of water. So little gluten is found, that the flour of oats can not be made into loaves of bread; although, mixed and baked as thin cakes, it forms a large part of the Scotchman's food. It requires thorough cooking, and is then slightly laxative and very easily digested.
Buckwheat is very rich in nitrogenous substances, and as we eat it, in the form of cakes with butter and sirup, so heating a food, as to be only suitable for hard workers in cold weather.
Indian corn has also a very small proportion of gluten, and thus makes a bread which crumbles too readily. But it is the favorite form of bread, not only for South and West in our own country, but in Spanish America, Southern Europe, Germany, and Ireland. It contains a larger amount of fatty matter than any other grain, this making it a necessity in fattening animals. In a hundred parts are eleven of nitrogen, sixty-five of carbo-hydrates, eight of fatty matter, one and a half of saline, and fourteen of water. The large amount of fatty matter makes it difficult to keep much meal on hand, as it grows rancid and breeds worms; and it is best that it should be ground in small quantities as required.
Rice abounds in starch. In a hundred parts are found seven and a half of nitrogen, eighty-eight of starch, one of dextrine, eight-tenths of fatty matter, one of cellulose, and nine-tenths of mineral matter. Taken alone it can not be called a nutritive food; but eaten with butter or milk and eggs, or as by the East Indians in curry, it holds an important place.
We come now to OLEAGINOUS SEEDS; nuts, the cocoanut, almonds, &c, coming under this head. While they are rich in oil, this very fact makes them indigestible, and they should be eaten sparingly.
Olive-oil must find mention here. No fat of either the animal or vegetable kingdom surpasses this in delicacy and purity. Palm-oil fills its place with the Asiatics in part; but the olive has no peer in this respect, and we lose greatly in our general distaste for this form of food. The liking for it should be encouraged as decidedly as the liking for butter. It is less heating, more soothing to the tissues, and from childhood to old age its liberal use prevents many forms of disease, as well as equalizes digestion in general.
LEGUMINOUS SEEDS are of more importance, embracing as they do the whole tribe of beans, pease, and lentils. Twice as much nitrogen is found in beans as in wheat; and they rank so near to animal food, that by the addition of a little fat they practically can take its place. Bacon and beans have thus been associated for centuries, and New England owes to Assyria the model for the present Boston bean-pot. In the best table-bean, either Lima or the butter-bean, will be found in a hundred parts, thirty of nitrogen, fifty-six of starch, one and a half of cellulose, two of fatty matter, three and a half of saline, and eight and a half of water. The proportion of nitrogen is less in pease, but about the same in lentils. The chestnut also comes under this head, and is largely eaten in Spain and Italy, either boiled, or dried and ground into flour.