16 



BULLETIN 102, U. S. DEPARTMENT OF AGRICULTURE. 



] ass"* 



bin at a terminal market. During the course of the experiment the 

 corn was allowed to go out of condition and underwent considerable 

 deterioration. The degree of acidity is shown as a factor in com- 

 parison with other factors which determine the quality and soundness 

 of corn. 



Corn under certain conditions may attain a temperature of 100° F. 

 or more before it becomes discolored or shows to the eye any 

 effect of damage by heat. Table X shows the effect of the increase 

 of temperature upon the degree of acidity, percentage of germina- 

 tion, and percentage of sound kernels as found in samples having 

 undergone ocean transportation. The samples were taken at 

 European ports at the time the vessels were unloaded. Nine cargoes 



are represented. The corn at the 

 time of loading was cool, the great- 

 est bulk of it being below 50° F. 

 Through ocean transportation cov- 

 ering a period ranging from 14 to 30 

 or 35 days 1 a large part of the 

 corn attained a temperature greater 

 than it had at the time of loading. 

 This increase varied from one or 

 two to over a hundred degrees in 

 the case of the badly damaged 

 portions of the cargoes. In the 

 table the degree of acidity and the 

 percentages of germination and of 

 sound kernels represent the av- 

 erage of all samples which showed 

 temperatures below 50° F., between 51° and 60°, between 61° and 

 70°, between 71° and 80°, between 81° and 90°, between 91° and 100°, 

 and above 100°, respectively, at the time of discharge of the cargoes. 

 Samples which attained a temperature of 71° or more showed marked 

 evidence of deterioration, and the higher the temperature the more 

 advanced the stage of deterioration and the higher the degree of 

 acidity. 



HEAT DAMAGE 

 I Q°/o 

 \ I 9.4°/o 



SOUND COf?/V 



GERM/NA T/O/V 



Fig. 14. — Graphic comparison of the condition of 

 corn at the time an elevator storage bin was 

 filled and at the time the bin was emptied, show- 

 ing the degree of acidity as a factor in compari- 

 son with other factors which determine quality 

 and soundness. 



Table X. — Degree of acidity, percentage of germination, and percentage of sov?}d IrrncJs 

 of samples representing 9 cargoes of exported corn, shoiving the effect of the increase 

 of temperature. 



Basis of comparison. 



Temperature of samples at time of discharge (° ¥.). 



Below 50°. 



51° to 60°. 



61° to 70°. 



71° to 80°. 



81° to 90°. 



91° to Above 

 100°. 100°. 





106 

 21.0 

 50.2 



88.38 



65 



21.4 



39.4 



84.4 



70 



26.8 



42.1 



SI. 65 



44 



31.9 



36.0 



71.68 



2S 



33.5 



21.7 



60. 73 



20 



33.7 



18.8 



50. 94 



109 



Degree of acidity c. c. . 



(termination per cent. . 



Sound kernels as determined by 

 mechanical analysis, per cent. 



42.5 

 4.2 



11.10 



1 In the case of one vessel a period of 50 days elapsed from the time of loading iint il the time of discharge. 



