The Chemistry of Food and Nutrition | Page 9

there is danger of taking insufficient water to hold freely
in solution the waste products excreted by the body.
Aerated drinks, except a very few of the best, and non-alcoholic beers
and wines, are generally unwholesome, from their containing
preservatives, foaming powders, artificial flavourings, &c.
Stimulants.--Tea and coffee contain an alkaloid theine, besides volatile
oils, tannin, &c. Cocoa contains the milder alkaloid, theobromine. They
stimulate the heart and nervous systems; tea and coffee have also a
diuretic effect. Formerly they were erroneously thought to lessen tissue
waste. These alkaloids, being purins, are open to the general objections
named elsewhere. Stimulants do not impart energy or force of any kind,
but only call forth reserve strength by exciting the heart, nervous
system, &c., to increased activity. This is followed by a depression
which is as great, generally greater, than the previous stimulation.
Except, perhaps, as an occasional medicine, stimulants, should be
avoided. Analysis of cocoa shows a good proportion of proteids and a
very large quantity of fat. The claim that it is a valuable and nutritious
food would only be true if it could be eaten in such quantities as are
other foods (bread, fruits, &c.). Were this attempted, poisoning would
result from the large quantity of alkaloid. The food value of half a
spoonful or thereabouts of cocoa is insignificant. Certain much
advertised cocoa mixtures are ridiculous in their pretentions,
unscientific in preparation, and often injurious.
Cereals.--The most valuable is wheat, from its proteid being chiefly in
the form known as gluten. From its tenacity, gluten enables a much
better loaf to be produced from wheat than from any other cereal. The
outer part of the grain is the richest in mineral matter and proteid.

Wheatmeal bread shows a considerably higher proteid value than white.
A large proportion of the proteid in the outer coats of the wheat berry is,
however, not digested, and in some experiments the waste has been
enough to quite nullify its seeming advantage over white bread.
Coarsely ground, sharp branny particles in bread irritate the intestines,
and cause excessive waste of nutriment; but finely ground wheatmeal is
free from this objection, and is beneficial in preventing constipation.
The comparative value of white and brown bread has been much
discussed; it depends both on the quality of the bread and the condition
of the digestive organs. Experiments on the digestion of bread and
other things, have often been made on persons unaccustomed to such
foods, or the foods have been given in excessive quantity. To those
accustomed to it good wheatmeal bread is much pleasanter, more
satisfying, and better flavoured than white; indeed, the latter is
described as insipid. Most bakers' bread is of unsatisfactory quality.
Flour and bread contain very little fat, the absence of which is
considered a defect. This is remedied by the addition of butter, fat or oil,
or by nuts, &c., which are rich in oil. These may be mixed with the
flour prior to cooking, or used afterwards.
Oats contain a substance called avenin, apparently an alkaloid, which
has an irritating action; the quantity is variable. It is to this that the
so-called heating effect of oatmeal on some persons is due.
Prepared Cereals or Breakfast Foods.--Analyses were made of 34 of
these cereal preparations by Weems and Ellis (Iowa State College
Agricultural Bulletin, 1904). They report that the foods possess no
nutritive value in excess of ordinary food materials; that the claim
made for many pre-digested foods are valueless, and no reliance can be
placed on the statement that they are remedies for any disease.
Oatmeal and other cereals are sold in packets as being partially cooked.
We do not doubt that they have been subjected to a dry heat, but this
has scarcely any effect on their starch and other constituents. The
difference is a mechanical one. In rolled oats the grains are so cracked
and broken, that on boiling with water, the water readily penetrates and
more quickly cooks them throughout. There are other prepared cereal
foods, but we doubt whether they are thoroughly cooked after the short
boiling directed on the labels. They are a great convenience where it is
difficult to get the time necessary for cooking the ordinary cereals.

Coarsely ground wheat is too irritating when made into porridge, but
there are some granulated wheats sold in packets, which are quite
suitable. The Ralston breakfast food is excellent. They are rich in the
phosphates and salts, found in the outer part of the grain. One cereal
preparation called Grape Nuts, has had its starch converted into maltose
and dextrin (maltose being a sugar), by a scientific application of the
diastase of the grain. It is consequently easier of digestion and requires
no cooking. It is beneficial for some forms of indigestion. There are
several competing