Apr. 15, 1919 Aleat Extracts, their Composition and Identification 1 1 



nitrogen. In the liver extract the "meat-base " nitrogen constitutes only 

 31.08 per cent of the total nitrogen. 



Chuck and plate extract 30 is much lower in "meat-base" nitrogen 

 than the other chuck and plate extracts. This is exceptional and is 

 undoubtedly due to the laboratory process used in its preparation, the 

 extraction having been made entirely with hot water. (See p. 2.) 



4. Proteose nitrogen (zinc-sulphate precipitate, Table III). — Al- 

 though the quantity of the proteose nitrogen varies from 9.35 to 32.23 

 per cent of the total nitrogen, the amounts in any one kind of extract are 

 not sufficiently constant to render the figure of any value in the identifica- 

 tion of extracts. On the whole, however, liver and spleen extracts are 

 somewhat higher in that constituent than other extracts. This factor is 

 probably influenced more by the precess used in the preparation of the 

 extract than by the material from which the extract is made. 



5. Creatin and crEatinin. — It is in the total creatinin content of the 

 various extracts that the greatest and most uniform differences occur. 

 The sum of the quantities of creatin and creatinin, together with the 

 ratio between this total and the total nitrogen of the extracts, is shown 

 in Table IV. It appears from these results that a determination of the 

 total creatinin will suffice in any case to classify an extract, if pure, as a 

 liver or spleen extract, on the one hand, or as a true meat extract on 

 the other. ^ 



It will be noticed at once that the liver and spleen extracts prepared 

 under commercial conditions contain about lo times as much total crea- 

 tinin as the laboratory extracts, attributable to the creatinin of the roast- 

 beef soak water, defibrinated blood, and blood water used in clarifying 

 these extracts. However, even though these commercially prepared 

 liver and spleen extracts are relatively high in creatinin, they are, never- 

 theless, much lower than any of the other extracts. The greatest quan- 

 tity of creatinin found in any of theliver and spleen extracts is 2.58 per 

 cent and the highest total creatinin — total nitrogen ratio^-0.37, while the 

 smallest amount of creatinin in the other extracts (except .the pickle 

 extract) is 5.38 per cent and the lowest ratio 0.46. From these results 

 it appears that all extracts of fresh flesh, with the exception of extracts 

 of liver and spleen, contain more than 5 per cent of total creatinin. 



6. Phosphorus. — Rather marked differences occur in the amounts of 

 phosphorus found in the extracts as well as in the relation existing 

 between the inorganic and total phosphorus present. 



The extracts of pickle and of corned-beef cook liquor contain very little 

 phosphorus, about 2 per cent; none of the other extracts contain less than 

 5 per cent with the exception of spleen extract 10. The laboratory liver 

 extracts are noticeably high in phosphorus. 



' Extracts from bones as made commercially will show a relatively high total creatinin. This is dvie 

 to the fact that the commercial bone extracts are essentially meat extracts, mobt of the extractives in 

 them being derived from the adherent meat and the clarifying agents which are used, and not from the 

 bones themselves. 



