34 



MEAT EXTRACTS. 



ciation of Official Agricultural Chemists for meat fiber and eoagulable 

 proteids in meat extracts were followed. 



The amount of insoluble material in several instances is extremely 

 large and the name "extract" hardly applies to such products. The 

 amount of eoagulable proteid in sample No. 17882 is very high. Xo 

 insoluble material should be present in a properly prepared extract. 

 As noted under meat juice, however, the eoagulable proteid is the 

 characteristic form of nitrogen for such products. Meat extracts, 

 both the solid and liquid, contain some eoagulable proteid. 



Table XIII. — Separation of insoluble and eoagulable nitrogen. 



Proteoses and Peptones. 



The following tentative standard for peptones has been framed by 

 the standards committee: 



Peptones are products prepared by the digestion of proteid material by means of 

 enzymes or otherwise, and contain not less than ninety (90) per cent of proteoses 

 and peptones. 



The proteoses and peptones are nitrogenous bodies of smaller 

 molecular weight and greater solubility and diffusibility than the 

 albumins. They are prepared from the albumins by the process of 

 hydration. The peptones are below the proteoses in the process of 

 hydrolysis. The distinction between the proteoses and peptones 

 usually considered is that made by Kuhne, a who defined the pro- 

 teoses as nitrogenous bodies precipitated by ammonium sulphate, 

 while the peptones are not precipitated by this reagent. These two 

 bodies also differ in solubility and as to certain chemical reactions. 



The zinc sulphate method 6 was employed for the determination 

 of the proteoses. The peptones were precipitated together with the 

 proteoses by the tannin-salt reagent and the peptone figures ob- 

 tained by difference. 



«ZtB. Biol., 1886. tS:42&. 



&U. S. Dept. Agr.. Bureau of Chemistry. Bui. 107, p. 115. 



cJJ. S. Dept. Agr., Bureau of Chemistry, Bui. 99, p. 182. 



