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 1 60 THE POPULAR SCIENCE MONTHLY 



cies worthy of consideration in the decomposition of meat. Ferments, 

 moreover, do not act at very low temperatures, although they are not 

 destroyed and resume activity when meat is thawed. 



Whether bacteria multiply at freezer temperature in liquid foods is 

 problematical. It is well established that bacteria die gradually in ice 

 so that after several months ice is practically sterile. Ice, however, 

 offers little nourishment for bacteria, while meat contains plenty of 

 food, which is available if water is present. Bacteria can not multiply 

 in solid substances and therefore multiplication in frozen meat is im- 

 possible. It is reasonable to assume that bacteria will die in frozen meat 

 as they do in ice. Conditions of frozen fish are quite similar to those 

 of meat and poultry. A few investigations of this problem are available 

 and, in substance, agree with the findings in frozen meat and poultry. 

 The bacteriological aspect of cold storage meats is largely speculative 

 and scientific investigations are much needed to throw light on the 

 problems of cold storage. 



In a general way the conclusions reached by those investigators who 

 have worked on cold storage problems are that there is no appreciable 

 difference in chemical composition between fresh meat and meat kept 

 frozen for periods longer than two years. No progressive changes could 

 be determined with precision. In regard to frozen poultry it has been 

 stated that the changes in chickens in 24 hours at 65 to 75° F. are 

 greater than in cold storage at 10° F. for 12 months. The changes 

 taking place in cold storage for 12 months are comparable to storage 

 in a house refrigerator for 5 days, or in the packer's chillroom at 32° F. 

 for 15 days, this not being sufficient time to bring about the tenderness 

 and flavor of so-called " ripened " meat. Most chickens bought in the 

 market as fresh are of poorer quality than chickens frozen for 12 

 months, and are poorer than many kept in cold storage for 16 months. 



The conclusion is inevitable that cold storage at 10° to 15° F. has no 

 deteriorating effect on the condition of meats, poultry and fish for a 

 period long enough to bridge over the time from one flush season to 

 the next, that is to say, for about 12 months. The term " deteriora- 

 tion " is a vague one and is interpreted largely on the basis of individual 

 opinion and taste. Some foods are not considered fit to eat unless they 

 have " ripened," but the ripening process is nothing but a decomposition 

 brought about by bacteria and molds. Cheeses of all kinds are per- 

 mitted to ripen for various periods of time and the changes taking place 

 during the ripening process are comparable from a chemical point of 

 view to the so-called deterioration of meat. The most delicate and 

 savory steaks are subjected to a ripening process, which consists in 

 storing them for 30 to 60 days at a temperature of 32°-40° F. During 

 this time the muscle fibers undergo changes, which render them more 

 soluble and consequently more tender, palatable and digestible. This is 



