Abstract
Pretreatment of milk powder with protease of Streptomyces griseus and Takadiastase B was shown to be necessary to extract thiamine perfectly from milk powder (Vitamins 39,109 (1969)). Further investigation of the procedure demonstrated that extraction of thiamine was most perfect on pretreatment of 5g milk powder with 0.2% Pronase-P at 37℃ for 16 hrs and then with 0.5% Takadiastase for 2-3 hrs. Contamination of thiamine in either Pronase-P or Takadiastase was negligible for estimation. Recovery test of thiamine diphosphate added to the sample was shown to be nearly 100% in the improved procedure, while only 80% recovery in HCl-extraction method.
