64 



DETAILS OF THE DIGESTION EXPERIMENTS. 



In the tirst series of tests six experiments were made to determine 

 the digestibility and nutritive value of the speciall}^ prepared macaroni. 

 In order to give variety to the diet without using an}^ considerable 

 number of food materials, bread made from some of the flour used for 

 the manufacture of the macaroni formed a part of the ration. This 

 flour made bread of good quality, with a characteristic yellow tinge. 

 The loaf was not quite as large or of so good quality as that made from 

 a like amount of the hard wheat patent flours made from samples 

 Nos. 497 and 498. The only food used in addition to cooked macaroni 

 and bread made from durum wheat flour was milk. In the flrst three 

 experiments about one-third more macaroni than bread (on the dr}^- 

 matter basis) was used, while in the last three experiments the ration 

 contained about two and a half times as much macaroni as bread. The 

 subjects were healthy men engaged in moderately severe labor. In 

 each case three subjects were used, and each experiment covered a 

 period of four days. 



The macaroni was prepared for the table by cooking in boiling 

 water for twent}^ minutes, and a Aveighed quantit}^ of the dried mate- 

 rial was cooked separatel}" for each subject. The water was drained 

 off and a small amount of milk added. The macaroni was then warmed 

 in an oven and served. Analyses were made of the waters drained 

 from the cooked macaroni and it was found that they contained from 

 0.03 to 0.04 per cent of the total nitrogen originall}' present in the 

 macaroni, as well as a somewhat larger amount of carbohydrates. In 

 ordinary household practice the material removed would be lost, as 

 the water in which the macaroni was cooked would be thrown awa3\ 

 The material lost constitutes about 2.25 per cent of the soluble mate- 

 rial originally present in the macaroni, which is about the same quan- 

 tity as is lost by the processes of fermentation followed in bread 

 making." It is natural to suppose that the quantity of water used 

 would affect the amount of material dissolved from the macaroni, and 

 it is obvious, therefore, that where strict economy is desired small 

 rather than large amounts of water should be used. In calculating 

 the results of the digestion experiments made in 1904 a correction was 

 introduced for the proteids lost in cooking by deducting 0.03 per cent 

 of nitrogen from the total amount present in the original material. 

 With this correction it was found that the dry matter of the uncooked 

 and the cooked macaroni had practically the same percentage compo- 

 sition. When compared on the basis of dry matter, little, if any, 

 difference was observed between the composition of the durum flour, 

 the cooked macaroni, and the durum-flour bread. In the experiments 

 made in 1905, the quantities of nutrients supplied by the cooked 



«U. S. Dept. Agr., Office of Experiment Stations Bui. 67, p. 33. 



