210 III. CHEMISTRY OF NEUTRAL FATS 



nut^^^ and palm kernel fat,-"* as is also the case with the palmitodimyris- 

 ^jjj^247,248 Myristodipalmitin has been reported as a component of palm 

 kernel fat.^** Stearodipalmitin has been found to be widely distributed in 

 natural products. It has been isolated from coconut oil,^''^ as well as from a 

 number of animal fats, including goose fat^"^-^" and duck fat"" (to the extent 

 of 3^%), lard (2%), 2^.252 and finally beef and mutton tallow.253.254 ^he 

 oleodipalmitin is found both in such vegetable sources as cacao butter, ^^""^ 

 Borneo tallow,"^ stillingia fat,"^ and in such animal fats as butter-"2.243 ^nd 

 goose fat.^"^ 



Palmitodistearins have been isolated only from animal sources, where 

 they have been sho^\^l to be components of lard,^"'-^^'^ butter,^"^'^"^ goose 

 fat,^*" and mutton and beef tallow.-^" On the other hand, the oleodistearin 

 has to date been reported only in vegetable fats (cacao butter, ^^-"2 Borneo 

 tallow,"^ and stillingia fat^^^). 



Several dioleins have also been prepared from fats. These include the 

 palmitodiolein in goose fat,^"^ which Bomer^^^ has indicated is present to the 

 extent of 30% in lard, and stearodiolein, which has been reported in the 

 same fat^^^ to an amount of 5%. 



Although much information concerning the structure of fats can be 

 gleaned from the presence of one or another mixed triglyceride, the 

 methods for their separation are exceedingly time-consuming and far from 

 quantitative. Soluble mixed triglycerides cannot be separated, and the 

 procedure is obviously not adapted to routine analysis. 



b. Methods of Analysis for the General Class of Triglycerides. Al- 

 though it is practically impossible to obtain anything but fragmentary 

 data about the glyceride composition of fats by isolation procedures, 

 Hilditch and his co-workers have developed routine laboratory technics 

 which enable one to classify the fats according to the proportion of sat- 

 urated and unsaturated fatty acids in the triglycerides. Thus, a natural 

 fat containing only stearic and oleic acids would have four different types of 

 triglycerides, which can be represented by the following formulae: 



Trisaturated glyceride (T) 



H2COOC(CH2),6CH3 

 HC00C(CH2),6CH3 

 HzCGOCtCHzlieCHs 



Tristearin 



250 A. Bomer and H. Merten, Z. Untersuch. Nahr. Genussm., 43, 101-137 (1922). 



251 A. Bomer, Z. Untersuch. Nahr. Genussm., 25, 321-353 (1913). 



252 C. Amberger and A. Wiesehahn, Z. Untersuch. Nahr. Genussm., 46, 276-299 (1923). 



253 W. Hansen, Arch. Hyg., 42, 1-15 (1902). 



254 IT. Kreis and A. Hafner, Ber., 36, 1123-1128 (1903). 

 256 J. Klimont, Monatsh., 24, 408-412 (1903). 



