79 



Table 62. — Arerage daily income and outgo of nitrogen in digestion experiments Nos. 



493-498, 593-597. 



Kind of food. 



Nitrogen. 



In food. 



Grams. 

 16.51 

 21.44 

 18.24 



20.33 

 22. 93 

 16.92 

 42.33 

 51.85 

 48. 58 

 28. 43 

 37.03 

 44.95 



In urine. 



Grams. 

 17.62 

 18.41 

 14.78 



17.35 



19.97 

 17.30 

 16.84 

 45. 91 

 59. 03 

 32.92 

 47.85 

 43.31 



In feces. 



Gain (+) 



or 

 los.s (-). 



Grams. 

 1.02 

 1. 39 

 1.62 



1.38 

 1.26 

 1.62 

 4.67 

 3.80 

 5.28 

 5.87 

 6.33 

 8.88 



Grams. 

 -2.13 

 +1.64 



+ 1.84 



+1.60 

 +1.70 

 -2.00 

 + 5.21 

 + .54 

 -3.93 

 -2.59 

 -4.29 

 -1.81 



In six of the experiments there was an average daih' gain of nitro- 

 gen and in an equal number there was a loss. As was noted in the 

 discussion of data regarding the income and outgo of nitrogen in 

 experiments with different sorts of bread reported earlier in this bul- 

 letin (p. 52), it is probable that in every case nitrogen equilibrium 

 would have been reached if the experimental periods had been longer. 

 On an average the proportion of nitrogen excreted in the feces was 

 greater with the durum wheat breakfast food, i. e., with the coarser 

 product, than with the macaroni, as might be inferred from the some- 

 what lower digestibility of the breakfast cereal referred to in the dis- 

 cussion of the digestion experiments. In general, no differences in the 

 nitroo-en balance were observed which could be attributed to the durum 

 wheat products consumed. 



CONCLUSIONS OF EXPERIMENTS WITH MACARONI. 



In these investigations two samples of durum wheat grown in North 

 Dakota were milled with an experimental mill at the Minnesota E^xperi- 

 ment Station and the product obtained was made into macaroni, which 

 was used for digestion experiments with healthy young men engaged 

 in a fair amount of muscular work as subjects. It was found that 

 when the offals from the durum wheat were remilled the total yield of 

 flour from durum wheat was approximately the same as from ordinary 

 wheats, but that the different grades of flour were obtained in somewhat 

 diflerent proportions. The durum wheat was somewhat harder to 

 reduce and required more power in milling than ordinary wheat. The 

 manufacture of semolina from durum wheat requires somewhat differ- 

 ent tempering, granulation, and bolting than are required in the manu- 

 facture of flour for bread-making purposes from ordinary wheat. In 

 the manufacture of macaroni the semolina or coarse flour undergoes 



