224 Journal of Agricultural Research voi. m. no. 3 



erties. This does not signify that the coloring matter of raw salted meat 

 is necessarily NO-hemochromogen, but rather it appears that treatment 

 with alcohol reduces the coloring matter of uncooked salted meats, 

 NO-hemoglobin, to NO-hemochromogen. In the case of certain uncooked 

 salted meats NO-hemochromogen may be present as such before extrac- 

 tion with alcohol. The best means of differentiating between NO- 

 hemoglobin and NO-hemochromogen as the coloring matters of salted 

 meats seems to be on the basis of their differences in solubiUty. NO- 

 hemoglobin -is soluble in water but insoluble in ether and alcohol, while 

 NO-hemochromogen is soluble in ether and alcohol and insoluble in 

 water. In other respects the properties of the two compounds are very 

 similar. 



In the case of certain kinds of uncooked salted meats and meat food 

 products — e. g., summer sausage and dried beef — the coloring matter 

 seems to be NO-hemochromogen rather than NO-hemoglobin. The 

 color is insoluble in water, but is soluble in alcohol and exhibits other 

 properties of NO-hemochromogen. 



It is very probable that in the case of meats which have been cured 

 with saltpeter or of meat food products in which saltpeter has been 

 used in the process of manufacture, the reduction of NO-hemoglobin 

 to NO-hemochromogen takes place to a greater or lesser degree, depend- 

 ing upon conditions of manufacture and storage. The two compounds 

 are so closely allied that their differentiation in one and the same product 

 is not a matter of great importance. 



CONCLUSIONS 



The results of the investigation reported in this paper may be briefly 

 summarized as follows : 



The color of uncooked salted meats cured with potassium nitrate, or 

 saltpeter, is generally due, in large part at least, to the presence of NO- 

 hemoglobin, although the color of certain kinds of such meats may be 

 due in part or in whole to NO-hemochromogen. 



The NO-hemoglobin is produced by the action of the nitric oxid 

 resulting from the reduction of the saltpeter used in salting upon the 

 hemoglobin of the meat. 



The color of cooked salted meats cured with saltpeter is due to the 

 presence of NO-hemochromogen resulting from the reduction of the 

 color of the raw salted meat on cooking. 



