1991 Volume 65 Issue 5-6 Pages 249-256
Vitamin B_1 contents in foods are determined by the thiochrome flurometric method (method 1) and high performance liquid chromatography with the post-column derivatization using potassium ferricyanide (method 2). In all foods studied, vitamin B_1 content determined by the method 1 agreed with the sum of 2-(1-hydroxyethyl) thiamin and thiamin contents determined by the method 2 (correlation coefficient=0.9996, n=43). 2-(1-hydroxyethyl)thiamin was newly found in dried purple laver, parsley, fish roe and Nameko. The contents of 2-(1-hydroxyethyl) thiamin and thiamin in pork, inside ham were recognized to be no change at +5℃ and -15℃ for 10 days. The destruction degree by heat depended on temperature and pH, and 2-(1-hydroxyethyl) thiamin was more sensitive to those factors than thiamin. It was found that a part of 2-(1-hydroxyethyl) thiamin was converted to thiamin by heat treatment.
