CHANGES IN FEESH BEEF DUEING COLD STORAGE. 



31 



It was not always possible to make cultures immediately, but they 

 were always made within two hours ; and during this time the block 

 of meat was kept wrapped in the bichlorid gauze and at cold-storage 

 temperature (3i°-36° F.). 



The short immersion in the boiling water served to coagulate the 

 muscle protein to the depth of from 3 to 5 mm., but did not cause 

 sufficient elevation of the inside temperature to have any injurious 

 effect on the bacteria present. A test was made by introducing a 

 thermometer into a block of meat of the size described above so that 

 the bulb rested at the center of the meat mass, and there was no 

 appreciable rise in temperature during the three minutes' interval in 

 the hot water. The outer zone of coagulated protein served to pre- 

 vent the penetration of the bichlorid solution into the meat. 



Beginning about 1 inch from the outer surface a series of cultures 

 were taken at intervals of an inch, pro- 

 ceeding from the outside toward the 

 bone, and these cultures were num- 

 bered as indicated in the diagram. In 

 taking the cultures a series of sterile 

 scalpels were used, one being used to 

 cut through the outer or surface por- 

 tion, and others to make deeper cuts 

 in order not to carry in any of the bi- 

 chlorid solution adhering to the sur- 

 face of the meat. Plugs of meat about 

 a centimeter square were used in mak- 

 ing the cultures. Cultures were made 

 in neutral beef broth and in glucose 

 agar from which the air had been ex- 

 pelled by boiling. When clouding occurred in the bouillon cultures, 

 agar plates were poured and the organisms present were j^lated out. 



In 4 of the 7 carcasses studied, a small micrococcus was found. This 

 organism was not generally distributed throughout the muscular 

 tissue of any one quarter, but was encountered here and there. The 

 fact that is was usually found at some distance below the outer sur- 

 face, together with the fact that it Avas found in the fresh or chilled 

 (liiarters as well as in the stored quarters, would indicate that it was 

 present in the carcass at the time of slaughter. In three of the cold- 

 stored carcasses, those held for 28, 54, and ()3 days, it was encountered 

 here and there and was not generally distributed through the mus- 

 cular tissues, which would indicate tluit there had been no multiplica- 

 tion of the organism during the str)rage of these (luaitcis. In tlu^ 

 quarter wliifh was held in storage for the longest period of time (i. e., 

 177 days) the micrococcus was found to be more generally distributed 



Fig. 1. — Diagram of a cross section 

 of a beef round, showing points 

 at which cultures were taken. 



