42 MEAT EXTRACTS. 



that succinic acid was a putrefaction product and its presence in 

 meat extract showed that fresh meat had not been used in manufac- 

 turing the extract. Siegfried held that the source of the succinic 

 acid is a definite substance of acid character and he called this sub- 

 stance " Phosphorfleisch Saure" or "Muskelnucleon." Later work, 

 however, indicates that succinic acid is a cleavage product of fresh 

 meat formed by the action, at high temperature, of dextrose or other 

 reducing substance on amido acids, especially aspartic acid. Conse- 

 quently, the presence of succinic acid in a meat extract does not 

 mean that spoiled meat was used in its manufacture. In 1904 two 

 or three brands of American meat extract were tested for the pres- 

 ence of succinic acid by means of ether extraction and the pine sliver 

 test and this body was shown to be present. . 



The question of the presence of succinic acid in meat extracts is 

 thoroughly discussed in a recent publication of the German Board of 

 Health. 6 " 



ETHER EXTRACT. 



The ether extract should not be above 0.6 per cent in a sample of 

 meat extract, as the fat is liable to become rancid and injure the 

 flavor of the product. Moreover, a high fat content shows lack of 

 care in preparing the extract. 



The provisional method employed for determining the ether ex- 

 tract c is conducted as follows: 



Dry the sample over night in the presence of dry sand in a lead dish 

 at the temperature of boiling water. Then thoroughly grind and 

 extract the dried sample with anhydrous ether, in a continuous ex- 

 traction apparatus for sixteen hours. Satisfactory duplicate results 

 are obtainable by this method, but it is the opinion of the authors 

 that the sample should be digested with pepsin and acid before ex- 

 tracting with ether, in order to break up the proteid matter and thus 

 expose the fat to the action of the ether more completely. 



GLYCEROL. 



That glycerol has Deen added to fluid meat extracts and other 

 similar preparations is well known, and it was found in several of the 

 samples reported in this bulletin. The purpose in adding it seems 

 to be to give the product additional smoothness and bod}". More- 

 over, glycerol is of considerable value as a preservative. Glycerol 

 is burned in the body and thus becomes a source of energy, but it 

 does not act as a proteid sparer. 



Various methods were tried for the determination of glycerol in 

 meat extracts and related products, including the method of the 



a Zts. physiol. Chem., 1903, 39 : 126. 



&Arb. kaiserl. Gesundheitsamte, 1906. vol. 24. 



cU. S. Dept.- Agr., Bureau of Chemistry, Bui. 107, p. 114. 



