EXPERIMENTAL MILLING AND BAKING. 
41 
of tap water until all the starch and soluble matter is. removed. This 
requires approximately 12 minutes. A piece of fine bolting cloth, 
stretched over two embroidery hoops or over a large-sized grain 
sieve, should be held under the dough while washing it. Allow the 
gluten thus obtained to stand in water for one hour, then press as dry 
as possible between the hands, roll in a ball in a tared flat-bottom 
dish and weigh as moist gluten. The transfer to an oven at 100° C. 
and dry to constant weight, which requires somewhat over 24 hours. 
Reweigh and calculate for dry gluten. Figure 31 illustrates the 
apparatus for making quantitative tests for gluten in flour. 
Fig. 33.— Laboratory table showing reflux condensers and electric hotplate for use in making gliadin 
determination. Fat extraction apparatus rear right of picture. 
GLIADIN IN FLOUR AND WHEAT. 
Put 4 grams of flour and 200 cubic centimeters of 50 per cent etlryl 
alcohol by volume, specific gravity 0.930 at 20° C, boiling point 83° 
to 84° C, into a 500 cubic centimeter Erlenmeyer flask. Connect t he 
flask with a reflux condenser and boil for 3 liours. Then allow it to 
cool and clarify by centrifuging. Draw off 100 cubic centimeters, 
representing a 2-gram sample, into a Kjeldahl flask, add 100 cubic 
centimeters of distilled water, 20 cubic centimeters of sulphuric acid, 
10 grams of sodium sulphate, 0.7 gram HgO, and determine nitrogen 
as described. The percentage of nitrogen divided by 2, time- 5.7, 
equals the gliadin. 
The following precautions are to be observed: Do not add the sul- 
phuric acid to the alcoholic solution before diluting with water. The 
addition of water precipitates the gliadin and prevents subsequent 
frothing, which will take place very easily unless these precaul 
are observed. The gliadin extraction apparatus is shown in Figure 33. 
