MICHIGAN ACADEMY OF SCIENCE. 
77 
making qualities. A high gluten content is desirable, provided the 
gluten is of good quality. 
The following table, prepared by Norton of South Dakota, shows this 
point very strikingly: 
Dry gluten Rank as to texture 
per cent. and quality. 
Five best straight durum wheat flours. 16.94 2 
Five poorest straight durum wheat flours. 17.12 3 
Five straight spring wheat flours. 14.82 2 
Two patent durum spring wheat flours. 13.38 1 
One patent spring wheat flour... 10.38 1 
The composition of the gluten is undoubtedly of more importance 
in determining the bread value of flour than the total gluten. Since 
gliadin and glutenin are the two principle proteids of wheat flour it is 
beleived by many that the ratio in which they exist in the flour deter¬ 
mines largely its value for bread-making. Many attempts have been 
made to determine the ratio that gliadin should bear to gluten to give 
the best results. The work done along this line indicates that the 
gliadin-glutenin ratio varies considerably in wheats grown under similar 
conditions from year to year and that these variations are accompanied 
with only minor differences in the size of the loaf and general bread¬ 
making value of the flour. Snyder states that “the results available at 
the present time indicate that the percentage amount of gliadin (or 
proteid soluble in 70 per cent alcohol solution) in a flour is of more 
value than Ithe gliadin-glutenin ratio,” and suggests that flour for 
bread making purposes should contain about 11 per cent of total pro¬ 
teids, and that 55 to 65 per cent should be in the form of gliadin. These 
standards are in accord with the conclusions reached by Norton of 
South Dakota, and so far as my experience has gone, it seems to be true 
of Michigan wheats, though probably the average proteid content of our 
Michigan wheats and flours made therefrom is somewhat below the 
standard set by Snyder. Mr. Frank T. Shutt, Chemist of the Central 
Experiment Farm, Ottawa, Can., reports that in the Canadian wheats 
he found the percentage amount of gliadin to be somewhat less than 
50. This suggests that either the Canadian wheats are lower in gliadin 
than are the wheats of our Northwest or possibly the gliadin is lacking 
in definite chemical composition. 
Thus it is seen that no hard and fast rule can be laid down for de¬ 
termining the bread-making value of wheats and flours. The most use¬ 
ful of all the chemical tests are the total proteid determination 
(Nx5, 7) and the gliadin determination. We know that a flour with a 
very high or a very low amount of gliadin will produce poor bread, but 
in other than extreme cases, the actual bread-making value of a flour 
can only be ascertained by comparative bread-making tests. It is alto¬ 
gether probable that there is some other factor, as yet undiscovered, 
which has an important influence in determining the bread-making 
value of wheats and flours. 
Agricultural College. 
