292 THE PEANUT— THE UNPREDICTABLE LEGUME 



and 50 percent relative humidity no pronounced fungus development 

 was noted at the end of 360 days. It is indicated, indirectly, that peanuts 

 stored at 80, 65 and SO percent relative humidity will have moisture con- 

 tents of approximately 10, 6.5 to 8, and 4 to 6 percent, respectively ( 170) , 

 and the effect of relative humidity on fungus growth must be through 

 the moisture content of the seed. 



Some rancidity developing in storage is not associated with fungus 

 activity but the result of enzymatic action. This also appears to be con- 

 ditioned by the factors of temperature, moisture and time. In the same 

 study (170) rancidity was measured by means of organoleptic tests and 

 peroxidase values. In general, rancidity developed along with or slightly 

 earlier than evident fungus activity. Apparently no attempt was made to 

 determine whether any rancidity developed independent of fungus 

 activity. It was concluded, however, that "at 50 percent relative humidity 

 storage life depends primarily on the development of oxidative rancidity 

 or some other factoi^ independent of moisture changes. . . ." Apparently 

 at 50 percent relative humidity rancidity does not develop as soon as it 

 does at 65 or 80 percent, but once beginning it develops more rapidly 

 (170). This may mean that rancidity developing at 50 percent relative 

 humidity is purely enzymatic in origin. 



Brittleness and sogginess are primarily a matter of moisture lost 

 or absorbed by the cotyledons. Brittleness develops when the moisture 

 content falls below 4 percent and sogginess develops at moisture content 

 above 10 percent. It may be assumed that the loss of viability of peanut 

 seeds in storage will be closely correlated with fungus and enzymatic 

 activity and thus conditioned by the same factors. 



Control. Peanut brokers, in general, avoid storing peanuts with 

 moisture, content above 8 to 10 percent, but the study cited ( 170) recom- 

 mends that the moisture content of stored peanuts should be held at 

 about 5 percent with the storage atmosphere at about 60 percent relative 

 humidity. 



Present recommendations for control of storage diseases of peanuts 

 may be summed up as follows: 



A. Cure and dry the peanuts as thoroughly as possible before storage. 



B. Control aeration in the storage area so that the relative humidity 

 of the storage atmosphere is kept as low as possible. 



