Dec. 15, I9I4 Coloring Matter of Salted Meats 223 



solution. The production of NO-hemoglobin by this method is un- 

 doubtedly due to the action of the nitric oxid, liberated from the unstable 

 nitrous acid, upon the hemoglobin. On heating the solution to boiling 

 a brick-red precipitate was formed which, after filtration and on extrac- 

 tion with alcohol, gave a light-red colored extract which showed a 

 spectrum with a fairly heavy band just at the right of the D line. Treat- 

 ment with sodium nitrite did not affect the color or spectrum of the 

 solution. 



A piece of lean beef about 3 inches square and 1% inches thick was 

 placed in a cold o.i per cent solution of sodium nitrite, and the sokition 

 was brought to the boihng point and boiling continued for one-half hour. 

 Immediately on placing in the cold nitrite solution the surface of the meat 

 turned dark brown in color; but on boiling, the meat took on a bright-red 

 color, similar to that of cooked corned beef. On cutting the cooked meat 

 the cut surface showed a bright-red color extending from the surface for 

 about one-fourth of an inch toward the center of the piece, the interior 

 of the meat being dark brown. The meat was ground and extracted 

 with alcohol, which gave a bright-red colored extract showing a spectrum 

 with a quite heavy band at the right of the D line and a very faint band 

 at the left of the E line. 



The color which Lehmann obtained on extracting with alcohol meat 

 which had been cooked in water containing nitrites and acid, he named 

 "haemorrhodin." Results obtained by Haldane and by the writer seem 

 to show, however, that the compound described by Lehmann is none 

 other than NO-hemochromogen. 



The following kinds of salted meats were used in studying the color of 

 cooked salted meats: Salami, cervelat, Frankfurter, and Bologna sausages, 

 corned beef, cured pork shoulder (unsmoked), smoked shoulder, and 

 smoked ham. Bologna and Frankfurter sausages are cooked in the proc- 

 ess of manufacture, so that these products are cooked salted meats. 

 Portions of each of the samples of meats were cooked for some time in 

 boiling water, then finely ground and extracted with alcohol. In all 

 cases a red-colored extract was obtained, the intensity of the color vary- 

 ing with the product. On spectroscopic examination the extract from 

 each sample showed a distinct band just at the right of the D line, but 

 in practically all cases a second absorption band was not visible. The 

 addition of sodium nitrite, as a rule, did not affect the color or spectrum 

 of the extract. The color of the cooked salted meats was soluble in 

 ether, but insoluble in water. 



The evidence seems to show very clearly that the color of cooked salted 

 meats is due to the NO-heniochromogcn resulting from the reduction of 

 the NO-hcmoglobin of the raw salted meats on boiling. 



It was found that the alcoholic extracts from the same product, 

 whether in raw or cooked condition, showed practically identical prop- 



