224. YEASTS AND MOLDS 
that the milk be sterilized hefore the batter was mixed since this allowed 
more uniform results and decreased the possibilities of the bad flavors 
which are so often inherent in this type of bread. 
Examination of Bread. The bactcrial examination of bread is 
important for two reasons: first, the possibility of bread spreading dis- 
ease bacteria; and secondly, the relation of bacteria to undesirable 
fermentations and changes which may take placc. 
Bread is generally regarded as an absolutely safe article in the diet 
since it is heated before eaten. Roussel (1908) stated that the interior 
of the loaf reached 101-108° C.; the crust reached 125-140.5° C. 
Such temperatures were regarded as sufficient to kill the vegetative cells 
but not the spores except they be present in the crust. Tubercle bacilli 
in the dough were reported to have retained their vitality. From these 
data Roussel states that mechanical mixers should be used in order to 
prevent the spread of disease. Auche (1909, 1910) introduced turbercle 
bacilli into dough before it was made into loaves. The loaves weighed 
up to2kg. The bacilli were killed in the baking process but the author 
regards it as a possibility that bacteria may pass through the baking 
process. In the latter paper cited, this same author added such bac- 
teria as the following to bread dough before baking: B. typh2, B. para- 
typhi, B. dysenterwe (Shiga), B. dysenteriw (Flexner), B. cols, Strept. 
pyogenes, Staph. aureus and a variety of proteus. Cultures made from 
the loaves after baking were sterile. Auche states that possibly more 
resistant bacteria would pass through the baking process. He states 
that the greatest care must be exercised to prevent contamination after 
the loaves have left the oven. Fenyvessy and Denies (1911) found that 
if the temperature of bread reached 94—104° C. during the baking process, 
the pathogenic bacteria, if accidentally present, would be destroyed. 
Gaujoux (1911), discusses some studies of this question. He found the 
Koch’s bacillus (Bacillus tuberculosis) did not survive the temperature 
of baking bread but assumed that it might pass through the temperatures 
employed for pastries. Howell (1912) examined bread collected from 
various districts in Chicago. In general it was found that bread made 
under clean conditions had a lower bacteria content and fewer strepto- 
cocci. Jacobs, LeClere and Mason (1914) studied the effect of wrapping. 
Wrapped bread had fewer bacteria on the surface. From the above 
discussion it would seem that bread may carry infection. The evidence 
is not altogether convincing, however, that it does. Hansen (1913) has 
reported a typhoid fever epidemic which may have been caused by bread. 
In this case the bread may have been contaminated after baking. 
Slimy or ropy bread has received quite a little attention from the 
