THE CHEMISTRY OF VEGETABLE FOOD.
We come now to the vegetable kingdom, the principal points that we are to
consider arranging themselves somewhat as follows:--
Farinaceous seeds,
Oleaginous seeds,
Leguminous seeds,
Tubers and roots,
Herbaceous articles,
Fruits,
Saccharine and farinaceous preparations.
Under the first head, that of farinaceous seeds, are included wheat, rye,
oats, Indian corn, rice, and a variety of less-known grains, all
possessing in greater or less degree the same constituents. It will be
impossible to more than touch upon many of them; and wheat must stand as
the representative, being the best-known and most widely used of all
grains. Each one is made up of nitrogenous compounds, gluten, albumen,
caseine, and fibrine, gluten being the most valuable. Starch, dextrine,
sugar, and cellulose are also found; fatty matter, which gives the
characteristic odor of grain; mineral substances, as phosphates of lime
and magnesia, salts of potash and soda, and silica, which we shall shortly
mention again.
_Hard Wheat_, or that grown in hot climates and on fertile soil, has much
more nitrogen than that of colder countries. In hard wheat, in a hundred
parts, twenty-two will be of nitrogen, fifty-nine starch, ten dextrine,
&c, four cellulose, two and a half of fatty matter, and three of mineral,
thus giving many of the constituents found in animal food.
This wheat is taken as bread, white or brown, biscuits, crackers, various
preparations of the grain whether whole or crushed, and among the Italians
as _macaroni_, the most condensed form of cereal food. The best macaroni
is made from the red wheat grown along the Mediterranean Sea, a hot summer
and warm climate producing a grain, rich, as already mentioned, in
nitrogen, and with a smaller proportion of water than farther north. The
intense though short summer of our own far North-west seems to bring
somewhat the same result, but the outer husk is harder. This husk was for
years considered a necessity in all really nutritious bread; and a
generation of vegetarians taking their name from Dr. Graham, and known as
Grahamites, conceived the idea of living upon the wheaten flour in which
husk and kernel were ground together. Now, to stomachs and livers brought
to great grief by persistent pie and doughnuts and some other New-England
wickednesses, these husks did a certain office of stimulation, stirring up
jaded digestions, and really seeming to arrest or modify long-standing
dyspepsia. But they did not know what we do, that this outer husk is a
layer of pure silica, one of the hardest of known minerals. Boil it six
weeks, and it comes out unchanged. Boil it six years, or six centuries,
and the result would be the same. You can not stew a grindstone or bring
granite to porridge, and the wheat-husk is equally obstinate. So long as
enthusiasts ate husk and kernel ground together, little harm was done. But
when a more progressive soul declared that in bran alone the true
nutriment lay, and a host of would-be healthier people proceeded to eat
bran and preach bran, there came a time when eating and preaching both
stopped, from sheer want of strength to go on. The enthusiasts were
literally starving themselves to death--for starvation is by no means mere
deprivation of food: on the contrary, a man may eat heartily to the day of
his death, and feel no inconvenience, so far as any protest of the stomach
is concerned, yet the verdict of the wise physician would be, "Died of
starvation." If the food was unsuitable, and could not be assimilated,
this was inevitable. Blood, muscle, nerve--each must have its fitting
food; and thus it is easy to see why knowledge is the first condition of
healthful living. The moral is: Never rashly experiment in diet till sure
what you are about, and, if you can not for yourselves find out the nature
of your projected food, call upon some one who can.
Where wheat is ground whole, it includes six and a half parts of
heat-producers to one of flesh-formers. The amount of starch varies
greatly. Two processes of making flour are now in use,--one the old, or
St. Louis process; the other, the "new process," giving Haxall flour. In
the former, grindstones were used, which often reached so great a degree
of heat as to injure the flour; and repeated siftings gave the various
grades. In the new, the outer husk is rejected, and a system of knives is
used, which chop the grain to powder, and it is claimed do not heat it.
The product is more starchy, and for this reason less desirable. We eat
far too much heat-producing food, and any thing which gives us the gluten
of the grain is more wholesome, and thus "seconds" is really a more
nutritious flour than the finer grades. Try for yourselves a small
experiment, and you will learn the nature of flour better than in pages of
description.
Take a little flour; wet it with cold water enough to form a dough. Place
it on a sieve, and, while working it with one hand, pour a steady stream
of water over it with another. Shortly you will find a grayish, tough,
elastic lump before you, while in the pan below, when the water is
carefully poured off, will be pure wheat-starch, the water itself
containing all the sugar, dextrine or gum, and mineral matter. This
toughness and elasticity of gluten is an important quality; for in
bread-making, were it not for the gluten, the carbonic-acid gas formed by
the action of yeast on dough would all escape. But, though it works its
way out vigorously enough to swell up each cell, the gluten binds it fast,
and enables us to have a panful of light "sponge," where a few hours
before was only a third of a pan.
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.
TUBERS and ROOTS follow, and of these the _Potato_ leads the van. Low as
you may have noticed their standing on the food-table to be, they are the
most economical and valuable of foods, combining as well with others, and
as little cloying to the palate, as bread itself. Each pound of potatoes
contains seven hundred and seventy grains of carbon, and twenty-four
grains of nitrogen; each pound of wheat-flour, two thousand grains of
carbon, and one hundred and twenty of nitrogen. But the average cost of
the pound of potatoes is but one cent; that of the pound of wheat, four.
It is obtainable at all seasons, and thus invaluable as a permanent store,
though best in the winter. Spring, the germinating season, diminishes its
nutritive value. New potatoes are less nutritious than older ones, and in
cooking, if slightly underdone, are said to satisfy the appetite better;
this being the reason why the laboring classes prefer them, as they say,
"with a bone in them."
In a hundred parts are found but two of nitrogen, eighteen of starch,
three of sugar, two-tenths of fat, seven-tenths of saline matter, and
seventy-five parts of water. The _Sweet-potato_, _Yam_, and _Artichoke_
are all of the same character. Other _Tubers_, the _Turnip_, _Beet_,
_Carrot_, and _Parsnip_, are in ordinary use. The turnip is nine-tenths
water, but possesses some valuable qualities. The beet, though also
largely water, has also a good deal of sugar, and is excellent food.
Carrots and parsnips are much alike in composition. Carrots are generally
rejected as food, but properly cooked are very appetizing, their greatest
use, however, being in soups and stews.
HERBACEOUS ARTICLES follow; and, though we are not accustomed to consider
_Cabbage_ as an herb, it began existence as cole-wort, a shrub or herb on
the south coast of England. Cultivation has developed it into a firm round
head; and as a vegetable, abounding as it does in nitrogen, it ranks next
to beans as a food. _Cauliflower_ is a very delicate and highly prized
form of cabbage, but cabbage itself can be so cooked as to strongly
resemble it.
_Onions_ are next in value, being much milder and sweeter when grown in a
warm climate, but used chiefly as a flavoring. _Lettuce_ and _Celery_ are
especially valuable; the former for salads, the latter to be eaten without
dressing though it is excellent cooked. _Tomatoes_ are really a fruit,
though eaten as a vegetable, and are of especial value as a cooling food.
Egg-plant, cucumbers, &c., all demand space; and so with edible fungi,
mushrooms, and truffles, the latter the property of the epicure, and
really not so desirable as that fact would indicate.
FRUITS are last in order; and among these stands first of all the apple.
While in actual analysis fruits have less nutritive value than vegetables,
their acids and salts give to them the power of counteracting the
unhealthy states brought about by the long use of dried or salted
provisions. They are a corrective also of the many evils arising from
profuse meat-eating, the citric acid of lemons and grape-fruit being an
antidote to rheumatic and gouty difficulties. Cold storage now enables one
to command grapes long after their actual season has ended, and they are
invaluable food. The brain-worker is learning to depend more and more on
fruit in all its forms; and apples lead the list, containing more solid
nutriment than any other form. While considered less digestible raw than
baked, they are still one of the most attractive, life-giving forms of
food, and if eaten daily would prove a standard antidote to patent
medicine. The list of fruits is too long for mention here; but all have
their specific uses, and are necessary to perfect health.
SUGAR and HONEY follow in the stores of the vegetable kingdom. Cane-sugar
and glucose, or grape-sugar, are the two recognized varieties, though the
making of beet-sugar has become an industry here as well as in France.
Grape-sugar requires to be used in five times the amount of cane, to
secure the same degree of sweetness. Honey also is a food,--a concentrated
solution of sugar, mixed with odorous, gummy, and waxy matters. It
possesses much the same food value as sugar, and is easily digested.
With the various FARINACEOUS PREPARATIONS, _Sago_, _Tapioca_,_
Arrow-root_, &c, the vegetable dietary ends. All are light, digestible
foods, principally starchy in character, but with little nutriment unless
united with milk or eggs. Their chief use is in the sick-room.
Restricted as comment must be, each topic introduced will well reward
study; and the story of each of these varied ingredients in cookery, if
well learned, will give one an unsuspected range of thought, and a new
sense of the wealth that may be hidden in very common things.