CHANGES INi'FEESH BEEF DUEING COLD STOEAGE. 93 



On account of the'many factors that seem to influence the forma- 

 tion of ammoniacal nitrogen and because of the small quantities of 

 ammoniacal nitrogen found in the beef, even after long periods of 

 storage, the changes in this constituent have not constituted a good 

 index of the extent of autolysis in the cold-stored beef ; nor can they 

 be regarded as being of any practical significance. The production 

 of ammonia is probably largely due to the combined action of several 

 proteolytic enzyms. 



Acidity. — The beef stored for 14, 28, and 177 days showed slight 

 apparent decreases in acidity, while that stored for 42, 63, and 74 

 days exhibited from slight to appreciable gains in that constituent. 

 The presence of acid-forming enzyms in muscular tissue is well 

 known, and the increases that took place in the acidity of the meats 

 were undoubtedly due, in large part at least, to enzym action. 



Total 'phosyhorus. — With the exception of the quarter of beef 

 stored for 14 days, each cold-stored quarter contained less total 

 phosphorus than the corresponding fresh quarter. This seeming 

 loss of phosiDhorus was accompanied in every case but one by a 

 corresponding loss in total nitrogen. Similar variations in total 

 phosphorus and total nitrogen were observed during the autolysis 

 experiment. Of themselves these data would go to show that phos- 

 phorus actually was lost from the meat during storage ; yet, in view 

 of the improbability of such an occurrence and the smallness of the 

 apparent losses, the evidence would scarcely justify such a conclusion. 



Insoluble ijhosyhorus was determined by difference, and what is 

 stated in the following paragraph applies inversely to this constituent. 



Total soluble yhosyhorus. — The changes that occurred in total 

 soluble phosphorus during the cold storage of the beef were of a very 

 irregidar nature. The changes were sometimes large and sometimes 

 small, sometimes positive and sometimes negative, but in no case 

 did they seem to bear any relation to any known factor. Even in 

 Experiment No. 7, where the storage period was 177 days, two de- 

 creases and one increase in this constituent were observed. It can 

 only be inferred that the solubility of some portion of the organic 

 phosp]iorus was influenced by some obscure factor that was not prop- 

 erly controlled in these experiments, and which escaped detection in 

 the autolysis experiment in consequence of the extensive cleavage of 

 insoluble phosphorus. Obviously, therefore, in the present case no 

 particular significance can be attached to these irregular changes. 



Holuble or(janic phosj)horus. — The changes that have occurred in 

 the soluble organic phosphorus of the beef during the storage periods 

 of these experiments appear to have been influenced not only by 

 the length of the storage period and by the temperature of storage, 

 but also by the relative amounts of preformed soluble organic and 

 inorganic phosphorus contained in the fresh material. In order that 

 those relations misy be studied, therefore, the experiments must be 

 class;ifi(!d, not only with reference to the time and the temperature 

 of storage, but also with n^gard to the initial distribution of soluble 

 organic and inorganic phos])horus. In reference to the latter fac- 

 tor, Experiments Nos. 2 and I sliould be f)la(ted in one gi-oup and the 

 other experiments in a second grouj), since the material used in ]*]x- 

 perimcnts Nos. 2 and 4 each fontained a gi-cater proportion of total 

 phosphorus in the soluble inorganic fonn and a smaller [)roportion 



