CAROTIN, THE PRINCIPAL YELLOW PIGMENT OF MILK FAT 359 



for study was a pure bred Holstein. The fat tested had a very high 

 color; a one inch layer gave a reading of 64 yellow, 5.0 red and 

 i.o light in the Lovibond tintometer. 



The unsaponifiable pigment and impurities from fifteen grams 

 of the fat had a golden yellow color in ether and in carbon bisulphide 

 a blood red color. This solution was analysed chromotographically. 

 The entire pigment passed through unadsorbed as a red orange or 

 rose colored zone, leaving no adsorbed zones and no pigment behind 

 in the CaCO 3 which could be washed out with ten per cent alcoholic 

 petroleum ether. The filtered solution showed two strong absorption 

 bands and a third faint one. (See Table 9.) 



The pigment was now analyzed according to its proportionate 

 solubility in petroleum ether (b. p. 30-50 C) and eighty per cent 

 alcohol, and was thus divided into two portions, a major portion ex- 

 tracted by the petroleum ether and a very minor portion which the pe- 

 troleum ether would not extract from the eighty per cent alcohol. 



The carotin-like pigment thus obtained was freed from choles- 

 terol by the digitonin method and its bands again measured in carbon 

 bisulphide solution. (See Table 9.) 



The residue from this solution gave a beautiful transient blue 

 color with concentrated H 2 SO 4 and a very transient blue-green color 

 with concentrated HNO 3 . 



The eighty per cent alcohol soluble pigment showed three absorp- 

 tion bands in carbon bisulphide solution, the first two being a little 

 more intense than the third. (See Table 9.) While in this solution 

 the pigment was analyzed by means of a chromotogramm and showed 

 two zones, a primary little adsorbed zone of orange color, and a sec- 

 ondary more adsorbed zone of yellow color. Hydrochloric acid gave 

 no color reaction with the alcoholic solution of the pigment of either 

 zone. 



TABLE 9. ABSORPTION BANDS OF PIGMENTS OF COLOSTRUM MILK FAT. 



Crystalline Form of Carotin From Butter Fat. The great concen- 

 tration of pigment in the fat from colostrum milk seemed to offer 

 an excellent opportunity to at least attempt the isolation of the pig- 



