Proteins Or Meats
Categories:
THE COAL FOODS
Sources:
A Handbook Of Health
Proteins, the First Foods. There are proteins, or meats, both
animal and vegetable; and no one can support life without protein in
some form. This is because proteins alone contain sufficient amounts of
the great element called nitrogen, which forms a large part of every
portion of our bodies. This is why they are called proteins, meaning
first foods, or most necessary foods. Whatever we may live on in later
life, we a
l began on a diet of liquid meat (milk), and could have
survived and grown up on nothing else.
Composition of Proteins. Nearly all our meats are the muscle of
different sorts of animals, made of a soft, reddish, animal pulp called
myosin; the other principal proteins being white of egg, curd of milk,
and a gummy, whitish-gray substance called gluten, found in wheat
flour. This gluten is the stuff that makes the paste and dough of wheat
flour sticky, so that you can paste things together with it; while that
made from corn meal or oatmeal will fall to pieces when you take it up.
The jelly-like or pulp-like myosin in meat is held together by strings
or threads of tough, fibrous stuff; and the more there is of this
fibrous material in a particular piece or cut, of meat, the tougher
and less juicy it is. The thick, soft muscles, which lie close under the
backbone in the small of the back, in all animals, have less of this
tough and indigestible fibrous stuff in them, and cuts across them give
us the well-known porter-house, sirloin, or tenderloin steaks, and the
best and tenderest mutton and pork chops.
Fuel Value of Meats. Weight for weight, most of the butcher's
meats--beef, pork, mutton, and veal--have about the same food value,
differing chiefly in the amount of fat that is mixed in with their
fibres, and in certain flavoring substances, which give them, when
roasted, or broiled, their special flavors. The different flavors are
not of any practical importance, except in the case of mutton, which
some people dislike and therefore can take only occasionally, and in
small amounts.
The amount of fat in meats, however, is more important; and depends
largely upon how well the animal has been fed. There is usually the least
amount of fat in mutton, more in beef, and by far the greatest amount
in pork. This fat adds to the fuel value of meat, but makes it a little
slower of digestion; and its presence in large amounts in pork, together
with the fact that it lies, not only in layers and streaks, but also
mixed in between the fibres of the lean as well has caused this meat to
be regarded as richer and more difficult of digestion than either beef
or mutton. This, however is not quite fair to the pork, because smaller
amounts of it will satisfy the appetite and furnish the body with
sufficient fuel and nutrition. If it be eaten in moderate amounts and
thoroughly chewed, it is a wholesome and valuable food.
Veal is slightly less digestible than beef or mutton, on account of the
amount of slippery gelatin in and among its fibres; but if well cooked
and well chewed, it is wholesome.
The other meats--chicken, duck, and other poultry, game, etc.--are of
much less nutritive value than either beef, pork, or mutton, partly
because of the large amount of waste in them, in the form of bones,
skin, and tendons, and partly from the greater amount of water in them.
But their flavors make them an agreeable change from the staple meats.
Fish belongs in the same class as poultry and consists of the same
muscle substance, but, as you can readily see by the way that it shrinks
when dried, contains far more water and has less fuel value. Some of the
richer and more solid fishes, like salmon, halibut, and mackerel,
contain, in addition to their protein, considerable amounts of fat and,
when dried or cured, give a rather high fuel value at moderate cost. But
the peculiar flavor of fish, its large percentage of water, and the
special make-up of its protein, give it a very low food value, and
render it, on the whole, undesirable as a permanent staple food. Races
and classes who live on it as their chief meat-food are not so vigorous
or so healthy as those who eat also the flesh of animals. As a rule, it
is not best to use fish as the main dish of a meal oftener than two or
three times a week.
Milk. Milk is an interesting food of great value because it combines
in itself all three of the great classes of food-stuffs,--protein,
starch-sugar, and fat. Its protein is a substance called casein, which
forms the bulk of curds, and which, when dried and salted, is called
cheese. The fat is present in little tiny globules which give milk its
whitish or milky color. When milk is allowed to stand, these globules of
fat, being lighter, float up to the top and form a layer which is called
cream. When this cream is skimmed off and put into a churn, and shaken
or beaten violently so as to break the little film with which each of
these droplets is coated, they run together and form a yellow mass which
we call butter. In addition to the curd and fat, milk contains also
sugar, called milk-sugar (lactose), which gives it its sweetish
taste. And as a considerable part of the casein, or curd, is composed
of another starch-like body, or animal starch, this makes milk quite
rich in the starch-sugar group of food-stuffs.
All these substances, of course, in milk are dissolved in a large amount
of water, so that when milk is evaporated, or dried, it shrinks down to
barely one-sixth of its former bulk. It is, in fact, a liquid meat,
starch-sugar, and fat in one; and that is why babies are able to live
and thrive on it alone for the first six months of their lives. It is
also a very valuable food for older children, though, naturally, it is
not strong enough and needs to be combined with bread, puddings, meat,
and fat.
Soups and Broths. Soups, broths, and beef teas are water in which
meats, bones, and other scraps have been boiled. They are about
ninety-eight per cent water, and contain nothing of the meat or bones
except some of their flavor, and a little gelatin. They have little or
no nutritive or fuel value, and are really Paper foods, useful solely as
stimulants to appetite and digestion, enabling us to swallow with relish
large pieces of bread or crackers, or the potatoes, rice, pea-meal,
cheese, or other real foods with which they are thickened. Their food
value has been greatly exaggerated, and many an unfortunate invalid has
literally starved on them. Ninety-five per cent of the food value of the
meat and bones, out of which soups are made, remains at the bottom of
the pot, after the soup has been poured off. The commercial extracts of
meat are little better than frauds, for they contain practically nothing
but flavoring matters.
Protein in Vegetables. Several vegetable substances contain
considerable amounts of protein. One of these has already been
mentioned,--the gluten or sticky part of bread,--and this is what has
given wheat its well-deserved reputation as the best of all grains out
of which to make flour for human food.
There is also another vegetable protein, called legumin, found in
quite large amounts in dried beans and peas; but this is of limited food
value, first because it is difficult of digestion, and secondly because
with it, in dried peas and beans, are found a pungent oil and a bitter
substance, which give them their peculiar strong flavor, both of which
are quite irritating to the average person's digestion. So distressing
and disturbing are these flavoring substances to the civilized stomach,
that, after thousands of attempts to use them more largely, it has been
found that a full meal of beans once or twice a week is all that the
comfort and health of the body will stand. This is really a great pity,
for beans and peas are both nourishing and cheap. Nuts also contain much
protein, but are both difficult of digestion and expensive.
Virtues and Drawbacks of Meats. Taken all together, the proteins, or
meats, are the most nutritious and wholesome single class of foods.
Their chief drawback is their expense, which, in proportion to their
fuel value, is greater than that of the starches. Then, on account of
their attractiveness, they may be eaten at times in too large amounts.
They are also somewhat more difficult to keep and preserve than are
either the starches or the fats. The old idea that, when burned up in
the body, they give rise to waste products, which are either more
poisonous or more difficult to get rid of than those of vegetable foods,
is now regarded as having no sufficient foundation. Neither is the
common belief that meats cause gout well founded.
The greatest danger connected with meats is that they may become
tainted, or begin to spoil, or decay, before they are used.
Unfortunately, the ingenious cook has invented a great many ways of
smothering, or disguising, the well-marked bad taste of decayed, or
spoiled, meat by spices, onions, and savory herbs. So, as a general
thing, the safest plan, especially when traveling or living away from
home, is to avoid as far as possible hashes, stews, and other made
dishes containing meat. This is one of the ways in which spices and
onions have got such a bad reputation for heating the blood, or
upsetting the stomach, when it is really the decayed meat which they are
used to disguise that causes the trouble. Highly spiced dishes rob you
of the services of your best guide to the wholesomeness of food--your
nose.
Risks of Dirty Milk. The risks from tainting or spoiling are
particularly great in the case of milk, partly on account of the dusty
and otherwise uncleanly barns and sheds in which it is often handled and
kept, and from which it is loaded with a heavy crop of bacteria at the
very start; and partly because the same delicateness which makes it so
easily digestible for babies, makes it equally easy for germs and
bacteria to grow in it and spoil, or sour, it. You all know how
disagreeable the taste of spoiled milk is; and it is as dangerous as it
is disagreeable. A very large share of the illnesses of babies and young
children, particularly the diseases of stomach and bowels which are so
common in hot weather, are due to the use of spoiled, dirty milk.
There is one sure preventive for all these dangers, and that is
absolute cleanliness from cow to customer. All the changes that take
place in milk are caused by germs of various sorts, usually floating in
the air, that get into it. If the milk is so handled and protected, from
cow to breakfast table, that these germs cannot get into it, it will
remain sweet for several days.
Boards of Health all over the world now are insisting upon absolutely
clean barns and cleanly methods of handling, shipping, and selling milk.
In most of our large cities, milk-men are not allowed to sell milk
without a license; and this license is granted only after a thorough
examination of their cattle, barns, and milk-houses. These clean methods
of handling milk cost very little; they take only time and pains.
Nowadays, in the best dairies, it is required that the barns or sheds in
which cows are milked shall have tight walls and roofs and good
flooring; that the walls and roofs shall be kept white-washed; and the
floor be cleaned and washed before each milking, so that no germs from
dust or manure can float into the milk. Then the cows are kept in a
clean pasture, or dry, graveled yard, instead of a muddy barnyard; and
are either brushed, or washed down with a hose before each milking, so
that no dust or dirt will fall from them into the milk. The men who are
to milk wash their hands thoroughly with soap and water, and put on
clean white canvas or cotton overalls, jackets, and caps. As soon as the
milk has been drawn into the pails, it is carried into the milk-room and
cooled down to a temperature of about forty-two degrees--that is, about
ten degrees above freezing point. This is to prevent the growth of such
few germs as may have got into it, in spite of all the care that has
been taken. Then the milk is drawn into bottles; and the bottles are
tightly capped by a water-proof pasteboard disc, or cover, which is not
removed until the milk is brought into the house and poured into the
glass, or cup, for use.
Milk handled like this costs from two to four cents a quart more to
produce than when drawn from a cow smeared with manure, in a dark,
dirty, strong-smelling barn, by a milker with greasy clothing and dirty
hands; and then ladled out into pitchers in the open street, giving all
the dust and flies that happen to be in the neighborhood a chance to get
into it! But it is doubly worth the extra price, because, besides
escaping stomach and bowel troubles, you get more cream and higher food
value. There is one-third more food value in clean milk than in dirty
milk, because its casein and sugar have not been spoiled and eaten by
swarms of bacteria. How great a difference careful cleanliness of this
sort can make in milk is shown by the difference in the number of
bacteria that the two kinds of milk contain. Ordinary milk bought from
the wagons in the open street, or from the cans in the stores, will
contain anywhere from a million to a million and a half bacteria to
the cubic centimeter (about fifteen drops); and samples have actually
been taken and counted, which showed five and six millions.
This method is used in many large dairies to avoid handling the udders
or the milk. Its chief drawback is that the long tubes are very
difficult to keep clean.]
Such a splendid food for germs is milk, and so rapidly do they grow in
it, that dirty milk will actually contain more of them to the cubic inch
than sewage, as it flows in the sewers. Now see what a difference a
little cleanliness will make! Good, clean, carefully handled milk,
instead of having a million, or a million and a half, bacteria, will
have less than ten thousand; and very clean milk may contain as low as
three or four hundred, and these of harmless sorts. The whole gospel of
the care of milk can be summed up in two sentences: (1) Keep dirt and
germs out of the milk. (2) Keep the milk cool.
The inside of the bottle is thoroughly cleansed by the revolving brush.]
Besides the germs of the summer diseases of children, which kill more
than fifty thousand babies every year in the United States, dirty milk
may also contain typhoid germs and consumption germs. The typhoid germs
do not come from the body of the cow, but get into the milk through its
being handled by people who have, or have just recovered from, typhoid,
or who are nursing patients sick with typhoid, and who have not properly
washed their hands; or from washing the cans, or from watering the milk
with water taken from a well or stream infected with typhoid. It is
estimated that about one-eighth of all the half million cases of
typhoid that occur in the United States every year are carried through
dirty milk.
The milk that spills or spatters over the hand drips back into the can
and may seriously infect the main supply.]
The germs of consumption, or tuberculosis, that are present in milk
may come from a cow that has the disease; or from consumptive human
beings who handle the milk; or from the dust of streets or houses--which
often contains disease germs. The latter sources are far the more
dangerous; for, as is now pretty generally agreed, although the
tuberculosis of cattle can be given to human beings, it is not very
actively dangerous to them; and probably not more than three or four per
cent of all cases of tuberculosis come from this source. The idea,
however, of allowing the milk of cows diseased from any cause to be used
for human food, is not to be tolerated for a moment. All good dairymen
and energetic Boards of Health now insist upon dairy herds being tested
for tuberculosis, and the killing, or weeding out, of all cows that
show they have the disease.
It is well to have the quality and purity of the milk tested just before
it goes to the consumer, but it is far more important that it should be
examined by State Inspectors at the dairy farms.]
Cheese. Cheese is the curd of milk squeezed dry of its liquid
(whey), salted, pressed into a mould, and allowed to ferment slowly,
or ripen, in which process a considerable part of its casein is turned
into fat. It is a cheap, concentrated, and very nutritious food, and in
small amounts is quite appetizing. But unfortunately, the acids and
extracts which have formed in the process of fermentation and ripening
are so irritating to the stomach, that it can usually be eaten only in
small amounts, without upsetting the digestion. Its chief value is as a
relish with bread, crackers, potatoes, or macaroni. In moderate amounts,
it is not only appetizing and digestible, but will assist in the
digestion of other foods; hence the custom of eating a small piece of
ripe cheese at the end of a heavy meal.