32 MASS. EXPERIMENT STATION BULLETIN 369 



The average digestion coefficient for nitrogen was 90 + 3.5 in the control diet 

 and 82 + 2 in the lignin diet. 



These data indicate that lignin is not only practically indigestible but that 

 it may affect the digestion of nitrogen. 



Effect of Storage and Processing on Carbohydrates of Some Varieties of 

 Edible Onions. (Emmett Bennett.) The work of the project was continued as 

 outlined with the exception that the use of "seed" (Yellow Globe Danvers) 

 onions was discontinued. 



"Set" (Ebenezer) onions were stored (A) in a warm room, (B) in a basement, 

 and (C) in a commercial storage from November 15 to February 27. Storage A 

 represented relatively high temperatures and low relative humidity; C, relatively 

 low temperatures and high relative humidity; and B, conditions intermediate 

 between A and C. The temperature and relative humidity were recorded reg- 

 ularly. Representative samples were obtained for analysis before and after 

 storage. 



The following results were obtained from the crop of 1938. The onions from 

 storages A, B, and C shrunk 19, 10, and 10 percent respectively and yielded 

 29, 62, and 87 percent of marketable onions. The shrinkage was caused prin- 

 cipally by respiration; apparent rotting was negligible in all cases. The sprouts 

 represented 69, 37, and 12 percent respectively. 



The dry matter of the fresh onions contained 59 percent sugars, of which 28 

 percent was reducing sugars and 72 percent was sucrose. During storage in 

 B and C this proportion changed to 49 percent of reducing sugars and 51 percent 

 of sucrose; and in A, to 34 percent of reducing sugars and 66 percent of sucrose. 

 This change was accompanied by a loss of total sugars, averaging about 15 

 percent, with a minimum of about 11 percent in storage B and C, and a maximum 

 of 24 percent in storage A. In general, the amount of total sugars lost by respira- 

 tion determined the amount of shrinkage during storage. The weight of fresh 

 onions which contained an amount of total sugars equal to the loss during storage 

 in B and C was found to be practically equivalent to the weight of onions which 

 was lost by shrinkage. This relationship was not true in storage A. 



Sucrose appeared to be the reserve carbohydrate. In storages B and C the 

 rate of respiration was sufficiently slow to allow reducing sugars to accumulate 

 at the expense of sucrose. In A, however, the rate of respiration was so rapid 

 that glucose was oxidized as rapidly as formed. 



While the sugar changes noted in the onions from storages B and C were almost 

 identical, the percentage loss from sprouting was 25 higher in B than in C. This 

 was believed to be due principally to the lower temperatures in storage C. 



The foregoing data indicate the following trends in the Ebenezer onion: 



1. The sugars appear to be mainly reducing sugars and sucrose, which may 

 make up approximately 60 percent of the dry matter. 



2. Sucrose is the reserve sugar, and prior to storage over 70 percent of the 

 total sugars may be in this form. 



3. Common storage practices produce an increase in reducing sugars and a 

 decrease in sucrose. 



4. Storage conditions may exist which produce sprouts but which do not 

 significantly increase the rate of respiration in the onions which do not sprout. 



5. Slightly lower temperatures may retard sprouting without significantly 

 altering the rate of respiration. 



The Progressive Decomposition of Haddock Muscle. (W. S. Ritchie and Philip 

 N. Simon.) Little is known concerning the systematic physico-chemical changes 

 taking place during the decomposition of the muscle proteins of fish. This study 

 is an attempt to elucidate some of the changes in the colloidal nature of the 



