96 BULLETIN 433, V. S. DEPABTMEISTT OF AGKICULTUEE. 



cuts from cold-stored meats than, from fresh meats ; and the wastage 

 becomes greater as the storage period is lengthened, other conditions 

 being the same. 



The third factor to be considered is the effect of the clianges in the 

 nature of the constituents of the meat upon the nutritive value of 

 the product. These changes have to do only with the edible portions 

 of the beef. 



The changes in the nitrogenous constituents of the meat Tiave been 

 in the nature of a process of autodigestion, the more complex nitrog- 

 enous compounds having been broken down into simpler compounds. 

 These changes are represented in Tables 12 to 60, inclusive, chiefly 

 by decreases in coagulable nitrogen and by increases in amino nitro- 

 gen. In general the extent of these changes has been greater the 

 longer the period of storage. Table 60 shows that in the fresh quarter 

 of beef from 2.47 to 2.53 per cent of the total nitrogen was present as 

 amino nitrogen, while the corresponding quarter after having been 

 stored for 177 days contained from 6.46 to 7.36 per cent of its total 

 nitrogen in that form, the increases having amounted to 3.99 and 4.83 

 per cent, respectively. 



In the light of our present knowledge concerning the functions of 

 amino acids in human nutrition, it seems improbable that the changes 

 that have taken place in the nitrogenous constituents of the meat, 

 even after very long periods of storage, have been such as to affect 

 appreciably the nutritive value of the product. 



The changes that have taken place in the other constituents of the 

 cold-storage beef have consisted principally in the breaking down 

 of soluble organic phosphorous compounds with a corresponding 

 formation of inorganic phosphates. Thus, the fresh quarter of car- 

 cass No. 7 contained from 22.19 to 26.78 per cent of its total phos- 

 phorus in the form of soluble organic phosphorus, while- the quarter 

 stored for 177 days contained but from 3.77 to 6.67 per cent of its 

 total phosphorus in that form. It is, therefore, apparent that a very 

 marked change has taken place in the nature of the phosphorous 

 compounds. 



The question as to the relative nutritive value of organic and inor- 

 ganic phosphorous compounds is one concerning which there is con- 

 siderable difference of opinion among those who have investigated 

 the subject. While it has been determined that, under certain condi- 

 tions, inorganic phosphates can be made to supply the phosphorus 

 requirement of the body, yet it has by no means been established that 

 phosphorus in inorganic combination has a nutritive value equal to 

 that of the organic forms of phosphorus. In the light of our incom- 

 plete knowledge concerning the relative nutritive values of organic 

 and inorganic forms of phosphorus, no positive conclusion can be 

 drawn regarding the effects of the changes in the nature of the 

 phosphorous compounds upon the nutritive value of the meat. 



On the whole it would appear that the chemical changes that 

 occurred during the storage of beef in these experiments did not 

 nppreciably affect the nutritive value of the meat when the period 

 of storage was limited to that customarily employed in commercial 

 practice. Indeed, even when the period of storage was greatly pro- 

 longed, evidence is lacking to show that the nutritive value of the 

 meat was diminished. Yet, in view of the more extensive chemical 

 changes that took place during the longer periods of storage and 



