Oct. 1. 1919 Method for Measuring Acidity of Cereal Products 



47 



received from the individual growers in the central coast region of Cali- 

 fornia and known to be of high quality were included in this experiment. 

 The titration results, calculated to the basis of dry weight, are given in 

 the following table . 



Table V. — Acidity values of different varieties of oats shown by the ice-water method^ 



Sample 

 No. 



62 



63 



64 



65 

 66 



67 

 68 

 69 

 70 



71 

 72 



73 

 74 



75 



Variety. 



Green Russian. 



Silvermine 



Canadian 



Silvermine 



Swedish Select. 



do 



Winter Turf.... 

 Red Rustproof. 



Sixty Day 



Victory 



Abundance 



Siberian 



Red Oats 



Black Oats 



Locality. 



Iowa 



do 



Idaho 



do 



North Dakota. 

 South Dakota. 



Virginia 



do 



South Dakota. 

 North Dakota. 



do 



do.. 



California 



do 



Crop 

 year. 



1914 

 1914 

 1915 

 1915 

 1915 

 1915 

 1915 

 1915 

 1915 

 I915 

 I915 

 1915 

 1914 

 1914 



Acidity 

 value. 



16.30 



23. 00 

 22. GO 



24. GO 

 13-50 



15- 75 

 17- 50 

 20. 00 

 13.60 



14. GO 



15- 50 

 19.90 



8.75 

 10. 50 



'Expressed in cubic centimeters of normal alkali required to neutralize the extract from 1,000 gm. of 

 material . 



If we compare the above acidity values with each other and with 

 those of the unsulphured but damaged oats in Table I, we find a remark- 

 able degree of uniformity, considering that the samples represent oats 

 of two seasons and grown in different localities. We observe, above 

 all, no essential difference in the values for the damaged oats (in Table I) 

 from those of the sound oats (in Table V). This clearly shows that 

 the amount of free acid present in oats does not change materially in the 

 unground kernel during the early stages of spoilage. The lowest acidities 

 found in sound oats were those of the two samples from the Pacific coast, 

 and in no case was the value as high as 25. Incidentally, there are indica- 

 tions that certain constant acidity values are characteristic of the different 

 varieties. Thus the values for samples 66 and 67 in Table V, which are 

 both of the Swedish Select variety and had been grown in different 

 States, are not far apart. Similarly, No. 63 and 65 df the Silvermine 

 variety show nearly the same acidity, although grown in different States 

 and seasons. 



SUMMARY 



(i) Various deficiencies of the Schindler method for measuring the 

 acidity of cereal products are pointed out. These deficiencies are 

 attributable to the presence of alcohol during the extraction and sub- 

 sequent titration. 



(2) A new and simple method is recommended for determining the 

 amount of free acid originally present in cereal products. The im- 



