ping qualities. Wheat oil has
cathartic properties, and it is believed the physiological action of
whole wheat and graham bread is in part due to the oil. The germ is also
rich in protein, mainly in the form of globulins and proteoses. A dough
cannot be made of pure germ, because it contains so little of the
gliadin and glutenin.

159. Aging and Curing of Flour.--Flours well milled and made from
high-grade, cleaned wheat generally improve in bread-making value when
stored in clean, ventilated warehouses for periods of three to six
months[9]. High-grade flour becomes drier and whiter and produces bread
of slightly better quality when properly cured by storage. If the flour
is in any way unsound, it deteriorates during storage, due to the action
of ferment bodies. Wheat also, when properly cleaned and stored,
improves in milling and bread-making value. Certain enzymic changes
appear to take place which are beneficial. Wheats differ materially from
year to year in bread-making value, and those produced in seasons when
all the conditions for crop growth are normal do not seem to be so much
improved by storing and aging, either of the wheat or the flour, as when
the growing season has been unfavorable. When wheat is stored, specific
changes occur in both the germ and the cells of the kernel; these
changes are akin to the ripening process, and appear to be greater if,
for any reason, the wheat has failed to fully mature or is abnormal in
composition.

The flour yield of wheat is in general proportional to the weight per
bushel of the grain, well-filled, heavy grain producing more flour than
light grain.[61] The quality of the flour, however, is not necessarily
proportional to the weight of the grain. It is often necessary to blend
different grades and types of wheat in order to secure good flour.

160. Macaroni Flour is made from durum wheat, according to Saunders a
variety of hard, spring wheat. It is best grown in regions of restricted
rainfall. Durum and other varieties of hard spring wheat grown under
similar conditions, differ but little in general chemical composition,
except that the gluten of durum appears to have a different percentage
of gliadin and glutenin, and the flour has a more decided yellow color.
Durum wheats are not generally considered as valuable for bread making
as other hard wheat. They differ widely in bread-making value, some
being very poor, while others produce bread of fair quality.[68]

161.