OCCURRENCE IN FOODSTUFFS 



Microbiological Assays 



For the microbiological assay of choline, the so-called cholineless 

 strain of Neurospora crassa has been used. This was obtained by 

 N. H. Horowitz and G. W. Beadle ^ by irradiation of A^. crassa with 

 ultra-\dolet light. It was used by R. W. Luecke and P. B. Pearson ^^ 

 for the estimation of choline in blood, urine and animal tissues. An 

 improved medium was described by A. Z. Hodson.^^ 



References to Section 4 



1. F. J. R. Beattie, Biochem. J., 1936, 30, 1554. 



2. A. D. Marenzi and C. E. Cardini, Rev. Soc. argent. Biol., 1942, 18, 



265. 



3. P. Cazeneuve, Compt. rend., 1900, 131, 346. 



4. H. P. Jacobi, C. A. Baumann and W. J. Meek, /. Biol. Chem., 



1941. 138, 571. 



5. R. W. Engel, ibid., 1942, 144, 701. 



6. D. Glick, ibid., 1944, 156, 643. 



7. C. Entenman, A. Taurog and I. L. Chaikoff, ibid., 1944, 155, 13. 



8. C, Entenman and I. L. Chaikoff, ibid., 1945, 160, 377. 



8a. W. Seaman, J. J. Hugonet and W. Leibmann, Anal. Chem., 1949, 

 21,411. 



9. N. H. Horowitz and G. W. Beadle, /. Biol. Chem., 1943, 150, 325. 



10. R. W. Luecke and P. B. Pearson, ibid., 1944, 153, 259 ; 1944, 155, 



507- 



11. A. Z. Hodson, ibid., 1945, 157, 383. 



5. OCCURRENCE OF CHOLINE IN FOODSTUFFS 



Very complete information is available concerning the choline 

 content of foodstuffs. Cereals and cereal products contain up to 

 I mg. per g. and meat and fish up to 5 or 6 mg. per g., so that as has 

 already been remarked (page 584) choline is present in these foodstuffs 

 in much larger amounts than other members of the vitamin B complex. 

 The only foodstuffs completely devoid of choline are fruits, whilst 

 vegetables, with the exception of legames, generally contain much 

 less than do cereals and animal products. 



Cereals 



The following values were obtained by R. W. Engel ^ for the 

 choline content of cereals : wheat, 0-92 ; wheat bran, 1-43 ; wheat 

 germ, 4-1 ; oats, 0-94 ; rolled oats, 1-51 ; barley, 1-39 ; polished rice, 

 0-88 ; rice polishings, 1-26 ; yellow corn, 0-37 ; corn meal, 0-42 ; white 

 flour, 0-52 ; and molasses (blackstrap), o-86 mg. per g. of fresh weight. 

 D. Glick 2 obtained the following values : hard spring wheat, 0-71 to 



587 



