662 



SCIENCE 



[Vol. LV, No. 1434 



Summary of Digestion Experiments in which Dairy Butter has been 



INCLUDED in a VARIETY OF EXPERIMENTAL DiETS 



Number 

 of experi- 

 ments 



Nature of food mate- 

 rial studied 



Butter 



Dasheen 



Soy-beau press-cake—. 



Peanut press-cake 



Kafir 



Feterita 



Milo 



Kaoliang 



Fine wheat bran 



Unground wheat bran 

 Hard Palates 



Amount of fat 

 eaten per sub- 

 ject daily, 

 grams 



100 



127 



92 



117 



67 



59 



72 



76 



134 



107 



127 



Per cent, of 

 butter in 

 total fat 

 consumed 



Digestibility of entire ration 



Protein 

 per cent. 



70^5 

 80.8 

 86.6 

 90.4 

 49.5 

 49.9 

 36.3 

 13.3 

 52.6 

 39.9 

 S7.3 



experimental diets -wliicli included edible fats 

 and oils. Eight tests were made with this tj'pe 

 of diet to determine the digestibility of butter 

 and it- was found that on an average butter 

 was 97 per cent, absorbed by the body. 



The studies of the food value and culinary 

 possibilities of the dasheen, a variety of the 

 taro {Colocasia esculenta), which is a staple 

 constituent of the diet in large areas of the 

 tropical countries, included a number of diges- 

 tion experiments." Since the advisability 

 of the introduction of the dasheen into the sub- 

 tropical regions of the country where the white 

 potato can not be successfully grown or stored 

 was under consideration, it was of considerable 

 importance to have data concerning its digesti- 

 bility. The basal diet for the digestion experi- 

 ments with dasheen consisted of milk, which 

 supplied the larger portion of the protein of 

 the diet, fruit, and butter, which, with the fat 

 from the milk, supplied the fat of the diet. 

 The carbohydrate portion of the diet was 

 largely derived from the dasheen. The results 

 of these experiments show butter to he 96 per 

 cent, digested when eaten as a part of a diet 

 in which the carbohydrates were largely starch, 

 derived from a starchy vegetable. 



During the World War when it became neces- 

 sary to conserve all resources to the utmost, the 

 writer became intensely interested in promoting 

 the use of the soy-bean and peanut press- 

 cakes for human food. The expression of oil, 

 under sanitary conditions, by the "cold 



11 "The Digestibility of the Dasheen," 

 Vept. Agri. Bid., 612 (1917), pp. 11. 



V. S. 



process" from sound, clean soy-beans or pea- 

 nuts produces a virgin oil and a high grade 

 press-cake rich in protein. These legume pro- 

 teins glyeinin (soy-bean) and arachin (peanut) 

 yield on hydrolysis a large amount of lysine, 

 the amino acid essential for growth. The re- 

 ported results of the chemical and biological 

 examination of soy-bean and peanut proteins 

 demonstrate beyond a doubt their high nutri- 

 tional value. In order to supplement this data 

 with information concerning the digestibility 

 of these proteins, digestion experiments^- were 

 conducted in which the soy-bean and peanut 

 press-cake flour combined with wheat flours 

 was served in the form of biscuits. The 

 experimentar diet consisted of biscuits, fruit, 

 butter, sugar and tea or coffee. Butter was 

 served as a spread for the biscuits and lard 

 was used as "shortening" in their preparation, 

 accordingly the values reported for digesti- 

 bility apply to the total fat of the diet rather 

 than to either individual fat, but as both 

 butteri^ and lard^" have been reported as being 

 97 per cent, digested, it is of interest to note 

 the effect of the soy-bean and peanut flour 

 diets on their digestibility. Since butter con- 

 stituted a half or more of the total fat of the 

 experimental diets and since the reported 

 digestibility for the total fat of the diets was 

 for the soy-bean experiments 94 per cent., and 



12 ' ' Digestibility of Protein Supplied by Soy- 

 bean and Peanut Press-cake Flours," U. S. Dept. 

 Agri. Bui, 717 (1918), pp. 28. 



13 ' ' Digestibility of Some Animal Fats, "U.S. 

 Dept. Agri. Bui, 310 (1915), pp. 22. 



