ACIDITY IN DETEKMININU SOUNDNESS OE COEN. 45 



SUMMARY. 



As a result of these corn-acidity investigations, the following facts 

 are well established: 



(1) All corn, unless in a state of putrefaction, contains acid-reacting substances 

 which impart to the corn a certain degree of acidity. 



(2) There is a great variation in the degree of acidity of corn, ranging from 9 or 10 

 c. c. to over 100 c. c. The degree of acidity can be determined by the acid test to 

 within 0.5 c. c. 



(3) The source of corn acidity is mostly in the germ. The source of increase in the 

 degree of acidity is almost entirely in the germ. 



(4) All corn judged damaged by the eye is higher in degree of acidity than corn judged 

 sound by the eye. 



(5) In a general way the degree of acidity of corn varies inversely with the germi- 

 native power. 



(6) The degree of acidity of corn increases directly with the percentage of damaged 

 kernels as determined by mechanical analyses. 



(7) The degree of acidity of corn is greatly increased by the action of fermentation 

 and high temperature. 



(8) Throughout the year, from harvest to harvest, there is a gradual increase in the 

 degree of acidity and a corresponding decrease in the percentage of germination of 

 corn arriving at terminal markets. 



(9) With respect to quality and soundness, the degree of acidity of corn is com- 

 mensurate with the commercial grading at terminal markets. 



(10) The degree of acidity of corn is a criterion of soundness and quality. 



(11) From the standpoint of commercial grading, corn with a degree of acidity less 

 than 22 c. c. is normally sound and of good commercial quality; corn with a degree of 

 acidity between 22 and 26 c. c. is somewhat inferior in quality and soundness, due to 

 deterioration of the germ; corn with a degree of acidity between 26 and 30 c. c. 

 evidences marked deterioration and is unsound; and corn with a degree of acidity 

 greater than 30 c. c. is badly damaged and should be considered from a commercial 

 standpoint as sample-grade corn. 



o 



WASHINGTON : GOVERNMENT PRINTING OFFICE : 1914 



