54$ MICROBIOLOGY OF FOODS 



and should come into the hands of the cook while still frozen hard. As 

 soon as portions become soft they should be cut off and cooked. The 

 extensive use of frozen beef during the war has proven so generally 

 satisfactory that previous prejudice against this kind of meat has been 

 largely forgotten. When once thawed it should be used promptly. 



Fish and poultry are usually frozen for storage. As these foods are 

 especially subject to rapid objectionable decomposition changes they are 

 rapidly chilled in ice water or by packing in ice immediately after 

 death, and are frozen as quickly as possible. During storage in the 

 frozen condition microbic activity is suspended, but in the subsequent 

 thawing the same physical and biological changes occur as in frozen 

 meat. When fish and poultry are stored in the undrawn condi- 

 tion there is an abundant supply of bacteria at hand in the intestinal 

 contents ready to multiply energetically during the chilling and thawing 

 stages. It would appear desirable that the poultry should be killed 

 and dressed with great care previous to freezing and that the period 

 of chilling should be shortened as much as possible. Practically, how- 

 ever, it has been found that the dressing of poultry, as ordinarily done, 

 previous to storage, leads to such an extensive soiling of the edible flesh 

 of the birds that their condition at the end of the storage period is often 

 less satisfactory than that of undrawn frozen poultry, not only in gross 

 appearance but also in respect to microbic content and chemical com- 

 position. Most frozen poultry is, therefore, stored in the undrawn 

 condition. 



The tendency of such food to undergo decomposition after thawing 

 should be clearly recognized and prompt cooking at once after softening 

 should be insisted upon. Its sale as fresh or as chilled food is a fraud 

 upon the purchaser. In fact many individuals seem to be pecu- 

 liarly liable to suffer digestive disturbances after eating frozen poultry 

 and such persons should avoid its use. 



The nature and source of the bacteria which produce poisonous 

 changes in poultry are not definitely known, but there is some evidence 

 indicating that they belong to the para-colon group and that they are 

 derived from the intestinal contents of the fowls. Smith and Ten- 

 Broeck* have studied a typhoid-like bacillus found in the intestinal 

 contents of fowls. This organism produces a poison which is only 



* Smith and TenBroeck, Journal of Medical Research, Jan., 1915, Vol. 31, No. 3, pp. 

 523-546. 



