1 86 



Journal of Agricultural Research 



Vol. XIX, No. 4 



Table II shows analyses of straight flours milled from the more im- 

 portant samples referred to in Table I. The samples in Table II are 

 designated by the same numbers as those in Table I, each number 

 followed by the letter "F." 



Table II. — Effect of freezing on nitrogen compounds cf straight four from Marquis uheat 



Percentage of total nitrogen in flour 



Percentage of nonprotein nitrogen in total 

 nitrogen 



Percentage of a-amino nitrogen in total 

 nitrogen 



Percentage of a-amino nitrogen in nonpro- 

 tein nitrogen 



Percentage of ammonia nitrogen in non- 

 protein nitrogen 



Percentage of amid nitrogen in nonpro- 

 tein nitrogen 



Percentage of amid nitrogen in total 

 nitrogen 



1917 series, sample No.- 



F. 



I. 84 



•27 



14-54 



3. 20 



12- 73 



•23 



7F. 



2. 46 

 4.40 

 I. 29 



29-44 

 4- 54 

 12. 31 



•54 



2-31 

 10.56 



4- 85 

 45-9° 



2.87 



10.33 



I. 09 



1918 series, sample No. — 



1300 F. 



2-37 

 3- OS 

 •57 

 19.90 

 3^40 

 12. 64 

 •38 



1306 F. 



2. II 



3. 60 



•53 



14- 74 



2. 30 



12. 90 



.46 



1307 F. 



Table II shows that the percentage of total nonprotein nitrogen is in 

 all cases considerably less in the flour than in the whole wheat, although 

 it is much greater in the frozen sample than in the matured ones, espe- 

 cially in the 19 1 7 series. This is not entirely in agreement with the find- 

 ings of Shutt (6) , who used Stutzer's method and reported that flour milled 

 from frosted wheat contained as high a percentage of its total nitrogen in 

 the albuminoid form as flour from sound wheat, although the frozen 

 whole wheat contained a larger percentage in the nonalbuminoid form 

 than did the sound wheat. His conclusion is that the nonalbuminoid 

 nitrogen compounds are practically all removed by the milling process 

 and may therefore be considered to be located in the bran and germ. 



The findings of Shutt agree much more closely with the 191 8 series 

 than with the 1917 series. Inspection of the figures for total nonprotein 

 nitrogen in Table II shows that a much greater proportion of the non- 

 protein nitrogen compounds was removed by milling in the 191 8 series 

 than in the 191 7 series. This indicates that either the freezing was of 

 such a nature that in one season it affected chiefly the nitrogen com- 

 pounds in the bran and germ, while in the other it affected the whole 

 kernel, or the difference has been caused by the different methods by 

 which the crops from the two series were handled after cutting, as has 

 previously been discussed in this paper. 



EFFECT OF FREEZING ON THE CARBOHYDRATES 



A brief study of the effects of premature freezing on the carbohydrates 

 of the wheat kernel was made. To this end wheat samples from both 

 series were analyzed by the methods of Stone (7). The results of these 

 analyses are presented in Table III. 



