Determination of Glucose, Galactose, and Lactose in their Mixtures

Open Access
Publisher Website
Google Scholar
Abstract
A method for determining the amt. of glucose, galactose, and lactose in hydrolyzed lactose sirups is outlined. The procedure was to determine the sum of the 2 hexoses by means of a modified Barfoed soln., and the amt. of glucose and lactose by following the directions of Shaffer and Somogyi before and after fermentation with washed bakers'' yeast. 4 samples of hydrolyzed lactose sirups were analyzed by this procedure and the results and steps in the calculations are described. Sirup No. 1, which attained a max. temp. of only 143[degree] C at the expiration of 35 min., still contained 8.6% lactose; whereas sirup No. 3, which was heated for 65 min., and 15 min. of this time the temp. was 143-147[degree] C, showed no lactose. There was, however, a loss of 2.37% in sugar content, which was converted into by-products. The reducing values of these by-products were of negligible amts. The max. error for the complete analysis should not exceed 7%.