124 ANNUAL EEPORTS OF DEPAETMENT OP AGEICULTUEE. 



under aseptic conditions during cold storage there is a marked 

 change of the creatin of meats to creatinin. 



Studies on the bacteriology of meats in cold storage were carried 

 out in close cooperation with the chemists working on the cold- 

 storage problem. While this work is not fully completed, the fol- 

 lowing conclusions seem warranted: (1) Certain bacteria, chiefly 

 micrococci, may be normally present in the carcasses of healthy 

 animals; (2) these bacteria do not appear to multiply in carcasses 

 stored at temperatures above freezing (32° to 36° F.) ; (3) the 

 bacteria found in normal carcasses are of no pathological significance ; 

 (4) bacteria and molds grow on the surface of cold-stored carcasses 

 but do not penetrate to any great depth (less than 1 inch). 



INVESTIGATIONS OF SOFT OR " MUSHY " HAMS. 



The investigation to determine the cause of the soft or mushy 

 condition at times found in hams has been continued. Additional 

 examinations have shown that while Sarcocystis miescheriana was 

 present in a considerable proportion (57 per cent) of the soft hams 

 examined, infestation with this parasite can not be regarded as the 

 cause of the soft condition of the muscle fibers, because in certain 

 typical examples of such hams the parasite was absent. Microscopic 

 sections have, however, revealed the presence of bacteria, and at 

 times yeast cells, in the softened portions of the ham. Putrefactive 

 bacteria and micrococci were almost constantly present in great 

 numbers in the soft portions, and apparently extended into the 

 firmer portions of the hams. The conclusion seems justified that 

 the soft or mushy condition is due to the action of bacteria, which 

 causes a disintegration of the tissue cells, this being later accentu- 

 ated by cooking. This subject will be given further study. 



DENATUEING AGENTS FOB FATS. 



Particular attention has been devoted to a study of mineral oils 

 as denaturants for fats. This required a study of the physical and 

 chemical properties of the denaturant, of the possibility of its re- 

 moval from fats, and its efi^ect on fats, both with regard to changes 

 produced in the taste, odor, and color and to the use of the denatured 

 fats for commercial purposes, as in soap making and the production 

 of lubricants. 



As a result of these investigations it was found that mineral oil, 

 such as gas oil, power distillate, or an equivalent having a boiling 

 point not less than 205° C, a flash point (open cup) not lower than 

 75° C, a specific gravity not lower than 42° B., and which may be 

 easily recognized by taste when present in the proportion of 1 part 

 of oil to 1,000 parts of fat, constituted a satisfactory denaturing 

 agent. The use of such oil has been permitted by the bureau as a 

 denaturing agent when added to carcasses and parts during the 

 process of rendering, or to fats which are rerendered, provided the 

 quantity of the denaturant is sufficient to make 1 part of the denatur- 

 ant in each 200 parts of anticipated yield of rendered grease. 



MISCELLANEOUS INVESTIGATIONS. 



Some work has been carried on concerning the composition of meat 

 extracts derived from various parts of the carcass; the study of the 

 changes which occur in canned meats after prolonged keeping has 



