Interference by amino acids in the estimation of sugars by reductometric methods

Abstract

Cu was appreciably reduced by cystine, tyrosine, and tryptophan in the Somogyi method but was less affected than ferricyanide. Casein hydrolysate reduced ferricyanide but not Cu, but added glucose gave incorrect values with Cu reagent and the reducing power for ferricyanide was not removed by precipitation with Ba, Cd or Hg. The amino acids were satisfactorily removed by shaking for 15 minutes with 1 g each of IR - 120 (H) and IR-4B (OH) for 6 ml of solution (50 mg of acid hydrolysate).