35 



VII. Flesh Foods. 

 NORMAL AND ABNORMAL COLORS. 



Among 1 the artificial coloring matters which may be considered are: 



Vegetable colors. Carmine, cochineal, logwood, archil, caramel, burnt chicory, 

 liquorice, elderberry juices, etc. 



Coal-tar colors. Fuchsin, magenta red, diamond red, safranin, fluoresceine, 

 eosines, ponceaus, Bordeaux reds, picric acid, benzopurpurin, and various mixtures 

 of several dyes. 



Vegetable colors are rarely used for flesh foods (Spaeth). 



The normal red color of flesh is due to the presence of several col- 

 oring matters. Hemoglobin is the dark-purple coloring matter of 

 venous blood. Oxyhemoglobin is the bright-red coloring matter of 

 arterial blood. Lipochrome is the rosy-red coloring matter present in 

 the muscular tissue of fishes. Healthy oysters may exhibit a green 

 color, due to a pigment termed marennin. Normal horseflesh may 

 exhibit a play of iridescent color. 



Various abnormal colors not due to added coloring matter may be: 



Yellow, due to food or to biliary compounds in disease. 



Brown, due to greenish-brown pigments. 



Dark purple, due to the animal having suffered from acute fevers, rinderpest, or 

 tuberculosis, or to insufficient bleeding after killing. 



Dark red, due to drowning or to suffocation in smoke (carbon dioxid poisoning). 



Dark brown, hunted or overdriven. 



Scarlet, from carbon monoxid poisoning or arsenic poisoning ( Walley ) . 



Diffused redness, from being frozen or to blood poisoning. 



Iridescence, from disease of the blood in animals other than the horse. 



Green or violet, commencement of putrefaction or diffusion of vegetable coloring 

 matter through the membranes of the stomach after death (Walley). In diseased 

 oysters due to green leucocytes. 



Various chromogenic bacteria a also produce bright red, blue, green, or violet color- 

 ations. 



The artificial coal-tar 5 colors used in sausages and meats in general 

 may be conveniently divided into the following classes: 



1. Those which color the meat but not the fat. In this case the surface of the 

 meat is coated mechanically with some of the color, while the fat remains perfectly 

 white. These dyes are insoluble in petroleum ether and generally insoluble in ether. 



2. Those which color the meat and fat uniformly red. These are only mechanic- 

 ally distributed and are not in solution, and by malting the mass the fat separates 

 colorless. These are insoluble in petroleum ether and generally in ether. 



3. Those which color the meat and fat a uniform red color, the color being in solu- 

 tion (soluble form). The separated fat from the melted mass remains red. These 

 colors are in general soluble in ether and insoluble in petroleum ether. 



Three methods c may be used to advantage in the examination of flesh foods, each 

 one having its advantage, viz: 



Consult C. A. Mitchell, Flesh Foods, 1900, p. 270. 



& Juckenack and Sendtner, Zts. Nahr. Genussm., 1899, 181. 



c 'See also Polenske Arb. Kaiserl. Gesund., 1900, 17, 568. Schweissing Pharm. 

 Centralb., 27, 441. Reinsch Zts. offentl. Chem., 1900, 485. Weller and Riegel 

 Forschungsb. , 1897, 4, 204. 



