CHAPTER XIII 
MEAT AND MEAT PRODUCTS 
Mzat is interesting from the bacteriological viewpoint for several 
reasons. As the activities of man became more complex, it became 
necessary to keep meat for future consumption. In order to do this, 
he had to study the action of the bacteria. The meat industry is one 
in which a large amount of capital is invested. Since meat is very sus- 
ceptible to the attacks of bacteria and since it may be taken from dis- 
eased animals, it has become necessary for the Federal authorities to 
control the slaughter and disposal of meat. The Federal Meat Inspec- 
tion Service of the United States Department of Agriculture is a public 
health agency which is constantly protecting the consumers. Melvin 
(1906) has outlined the scope and application of the laws governing 
this product. The opinions regarding what constitutes diseased meat 
are by no means in agreement. Stiles (1917) has discussed this subject 
and pointed out that there are several definitions of the term “ diseased ”’ 
as applied to meat. Meat is essentially protein in composition and this 
chemical constitution determines the type of decomposition to which 
it is susceptible. 
Origin of Bacteria in Meat. The presence of bacteria in the organs 
and flesh of healthy animals is still a debated question. Many investi- 
gators have reported their presence but the health of the animal in 
these instances may be questioned. Maurel (1911) found a diplococcus 
in meat. Conradi (1909), using a special enrichment method found 
aerobic and anaerobic bacteria in muscles and organs. Bierotti and 
Machida (1910) secured similar results. Zwick and Weichel (1911) 
found bacteria frequently in the liver but not in the muscles with the 
exception of one case. Conradi (1909) in examining many organs 
found bacteria but concluded that they came from the intestines, being 
absorbed along with the food. Hoagland et al. (1917) in studying the 
changes in beef during storage above freezing, states as follows with 
regard to the presence of bacteria: 
Certain bacteria (chiefly micrococci) may be normally present in the carcass 
of healthy animals slaughtered for beef. These bacteria possess no pathological 
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