10 BULLETIN 1033, U. S. DEPARTMENT OF AGEICULTUEE. 



sion which follows such fats are designated " blended fats " in con- 

 trast to the " hydrogenated oils " made by hydrogenating the entire 

 quantity of oil. 



It has been claimed that this blended fat is inferior in keeping quali- 

 ties to that produced by hydrogenation alone/^ The blending method 

 is, however, generally given preference because of the larger produc- 

 tion possible with a given equipment. Moreover, the blended fat 

 may supply vitamins, if any were present in the oil that is blended 

 with the hardened fat, 



A previous paper from this laboratory reported a series of 44 

 experiments on corn, cottonseed, and peanut oils hydrogenated to dif- 

 ferent degrees of hardness. ^^ It v/as found that with the exception of 

 hydrogenated peanut oil melting at 52.4 ° C, which was 79 per cent 

 digested, and corn oil melting at 50 ° C, which was 88.5 per cent di- 

 gested, the hydrogenated oils studied had coefficients of digestibility 

 of 92 per cent or higher. No one of them caused any observed diges- 

 tive disturbance nor was a decrease in the digestibility of the experi- 

 mental diet as a wdiole noted in any case. In general, the results 

 showed that as the melting point of the hydrogenated oil increased 

 the digestibility decreased, the decrease being much more marked 

 with those melting at over 46° C. 



To determine whether or not blended fats have the same digesti- 

 bility as hydrogenated oils made from the same kinds of oils and hav- 

 ing approximately the same melting point, such blended fats ware 

 used in the experiments here reported. They were made for the pur- 

 pose from the same lots of corn, cottonseed, and peanut oils used in 

 the earlier experiments with hydrogenated oils.^° 



The hard fats used in the preparation of the majoritj'' of the 

 blended fats were prepared in the laboratory of Carleton Ellis by 

 one of the authors (H. J. D.) of this bulletin assisted by J. R. Kuhn. 

 The oils were completely saturated with hydrogen at 180° C. and had 

 a melting point, in every case, of approximately 60° C. In the 

 case of the two blended cottonseed fats, with melting points of 

 41.3° C. and 50° C, cotton stearin obtained from the Bureau of Ani- 

 mal Industry was mixed with a good grade of commercial edible 

 cottonseed oil obtained from the Bureau of Chemistry. The melting 

 points, iodin numbers, and proportions of hardened and untreated oil 

 in the fats used are shown in Table 10, page 13. 



These blended fats were white, solid or practically so at room 

 temperature, and without an}^ characteristic odor or taste. When 

 melted, their color was yellow, resembling that of tallow. If alloAved 



^8 Rogers, A. Manual of Industrial Chemistry. 1915, 2. ed., p. 601. 

 "Holmes, A. D., and Deuel, H. J., jr., Amer. Joui-. Physiol., 54 (1921), No. 3, pp. 

 479-488. 



20 Amer. Jour Physiol., 54 (1921), No. 3, pp. 479-488. 



