the lowest grades of flour, the
increase being practically proportional to the grade,--the most ash
being in the lowest grade. The grade to which a flour belongs can be
determined more accurately from the ash content than from any other
constituent. Patent grades of flour rarely contain more than 0.55 per
cent of ash,--the better grades less than 0.5 per cent. The more
completely the bran and offals are removed during the process of
milling, the lower the per cent of ash. The ash content, however, cannot
be taken as an absolute guide in all cases, as noticeable variations
occur in the amount of mineral matter or ash in different wheats;
starchy wheats that have reached full maturity often contain less than
hard wheats grown upon rich soil where the growing season has been
short, and from such wheats a soft, straight flour may have as low a per
cent of ash as a hard first patent flour. When only straight or standard
patent flour is manufactured by a mill, all of the flour is included
which would otherwise be designated first and second patents and first
clear.

157. Graham and Entire Wheat Flours.--When the germ and a portion of
the bran are retained in the flour, and the particles are not completely
reduced, the product is called "entire wheat flour." The name does not
accurately describe the product, as it includes all of the flour and
only a portion of the bran, and not the entire wheat kernel. Graham
flour is coarsely granulated wheat meal. No sieves or bolting cloths
are employed in its manufacture, and many coarse, unpulverized
particles are present in the product[62].

158. Composition of Wheat Offals.--Bran and shorts are characterized
by a high percentage of fiber, or cellulose. The ash, fat, and protein
content of bran are all larger than of flour. The protein, however, is
not in the form of gluten, but is largely albumin and globulins,[16]
which are mainly in the aleurone layer of the wheat kernel, and are
inclosed in branny capsules, and consequently are in a form not readily
digested by man.

[Illustration: FIG. 42.--FLOUR AND GLUTEN.

1, flour; 2, dough; 3, moist gluten; 4, dry gluten.]

The germ is generally included in the shorts, although occasionally it
is removed for special commercial purposes. It is sometimes sterilized
and used in breakfast food products. The germ is rich in oil and is
excluded from the flour mainly because it has a tendency to become
rancid and to impart to the flour poor kee