It has
been estimated that the average composition of this grain is as follows:
PER CENT.
Protein...................................... 11.9
Fat.......................................... 2.1
Carbohydrates................................ 71.9
Mineral salts................................. 1.8
Water........................................ 10.5
Cellulose..................................... 1.8
Total....................................... 100.0
[Illustration: Fig. 1]
So that the composition of wheat and the making of wheat flour may be
more clearly understood, it will be well to observe the structure of a
grain, or kernel, of wheat, which is shown greatly enlarged in Fig. 1.
At _a_ is shown the germ of the young plant, which remains undeveloped
until the grain is planted. This part contains practically all the fat
found in the grain, some starch, and a small quantity of protein. At _b_
is shown the inside of the kernel, or the _endosperm_, as it is called,
which is composed of starch granules interlaced with protein and mineral
salts. Surrounding these, as at _c_, is a layer of coarse cells that
contain mineral matter and protein, and between these cells and the
outer husk, as at _d, e, f_, and _g_, are layers of bran, which are
composed of cellulose and contain mineral salts and small quantities of
starch and protein.
Pages:
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223