200 III. DIGESTIBILITY OF FATS 



Table 2 

 Typical Diets Used in Digestibility Experiments with Rats 



Augur 



et al. a Cheng Savage 

 Augur (Hydro- Deuel et al. e and Calbert 

 et al. a genated et al. h (Various Deuel'* et al.* 

 (Fat- cotton- (Rape- triglycer- (Jojoba (Mar- 

 free), seed oil), seed oil), ides), oil), garine), 

 Food component % % % % % % 



Commercial casein 18 18 18 18 9.0 18 



Test fat 15 15 15 14.8 15 



Glucose 71 56 56 61 



Sucrose — 26.0 46 



Starch — 38.0 



Salt mixture 7 7 7 7 5" 4.0 7 



Yeast* 1 1 1 1 8.0 4 



Liver extract* 3 3 3 — — 



Isopropyl or stearyl citrate. . . ■ — — — — — 10 



Fat-soluble vitamin mixture . . — — — — 0.2 — 



a V. Augur, H. S. Rollman, and H. J. Deuel, Jr., J. Nutrition, 38, 177-186 (1947). 



6 H. J. Deuel, Jr., A. L. S. Cheng, and M. G. Morehouse, /. Nutrition, 35, 295-300 

 (1948). 



e A. L. S. Cheng, M. G. Morehouse, and H. J. Deuel, Jr., /. Nutrition, 37, 237-250 

 (1949). 



d E. E. Savage and H. J. Deuel, Jr., Unpublished results, 1952. 



« C. E. Calbert, S. M. Greenberg, G. Krvder, and H. J. Deuel, Jr., Food Research, 16, 

 294-305(1951). 



/ T. B. Osborne and L. B. Mendel, J. Biol. Chem., 32, 309-323 (1917). 



Calcium- and magnesium-free salt mixture emplo}^ed. 



h Anheuser-Busch, Strain G. 



»' Wilson and Co., 1 : 20 concentrate. 



The length of the experimental period can be adjusted according to the 

 convenience of the experimenter. However, the shorter the experimental 

 period, the greater the danger of error due to inaccuracies in the separation 

 of the feces. In our laboratory, the duration of the tests has usually been 

 eight or nine days, in addition to the two-day orientation period. An 

 accurate record is kept of the total food consumed during the eight- or 

 nine-day period; the last weighing of the food is done on the morning of 

 the ninth or tenth day, respectively. Any food which is spilled during the 

 test is collected and weighed ; the record of food consumed is corrected by 

 this factor. Total fat or lipid can be estimated from the food consumption, 

 and the analysis for the lipid is based upon determinations of several por- 

 tions of diet. 



The feces are collected at frequent intervals during the experimental 

 period, care being taken to separate them mechanically from any adherent 

 food particles. The feces collection is terminated on the morning of the 

 ninth or tenth day, coincident with the last weighing of the food cups. 



