Oct. 15, 1925 
753 
(Jhloropicrin as a Fumigant for Cereal Products 
These effects of the chloropicrin on the properties of the gluten 
were shown by other methods. Twenty-gram quantities of the flours 
were washed first with 1,000 c. c. and then with 500 c. c. of distilled 
water, and the viscosity determined in the manner outlined by Gort- 
ner and Sharp ( 14)• The control flour at this concentration showed 
a viscosity of 197° McMichael. Two treated flours gave values of 
146° and 151°, respectively. This again bears out the fact that the 
chloropicrin affects the ability of the gluten of flour to imbibe water 
from a weak acid solution. 
In order to measure any effects on the elasticity or tenacity of the 
gluten or rather of the dough, certain experiments were carried out 
with the Chopin (11) extensimeter. In the use of this apparatus, 300 
gms. of flour is made into a dough with 5 per cent sodium-chloride 
solution. Portions of this dough are pressed into a thin layer be¬ 
tween metal plates. This thin sheet of dough is held in place so that 
air can be introduced from below. Under air pressure, the dough 
can be blown into a thin membrane which takes the shape of a bubble. 
The size of the bubble so formed indicates certain properties of 
elasticity of the dough. 
Samples of treated and untreated flour were tested in this manner. 
The untreated flour gave a value of 16.26. Two samples of the same 
flour fumigated with chloropicrin gave values of 13.8 and 13.2, 
respectively. 
From the data, it is evident that chloropicrin affects the properties 
of gluten to a marked degree. However, the flours were given drastic 
fumigation treatment, probably much more severe than they would 
receive in a mill or elevator. It appears that the chloropicrin is 
retained rather tenaciously by the flour. This is shown by the fact 
that when treated flour having no odor of chloropicrin is mixed with 
water the chloropicrin is set free as indicated both by odor and by its 
effect on the eyes. Probably the best method to determine whether 
flour has been treated with chloropicrin is to taste it. A sharp, biting 
taste will indicate the presence of chloropicrin even where any analyt¬ 
ical method known would probably give negative results. 
BREAD-MAKING EXPERIMENTS 
Attention will now be directed to the effects of chloropicrin on 
flour and yeast in mixture as used in bread making. The baking 
procedure is that recommended by Bailey (#), 450 gms. flour being 
used in the preparation of the dough, one-third of which is subse¬ 
quently placed in the expansimeter. Table IV gives the results 
and Figure 3 shows sections of the bread so prepared. The bread 
shown in Figure 3 will be referred to as the series of July 13, 1923. 
The No. 1 bread was made from the untreated control flour. 
A portion of the same flour from which gluten No. 3 in Table 
III had been prepared was used in this baking series. It had, how¬ 
ever, been lying spread out in a thin layer for two weeks, and glutens 
prepared from it at the end of this additional exposure to the atmos¬ 
phere compared quite favorably with those prepared from the 
untreated flour. Also, the bread baked from this excessively treated 
flour compared favorably with that baked from the untreated flour. 
These observations seemed to indicate that treated flours, if given 
sufficient areation or exposure to the atmosphere, may recover 
from the effects of the chloropicrin treatment. These effects, there- 
