Determination of Ethanol in Whey-Sugar Solutions by Freezing

The composition of solutions undergoing yeast fermentation was simulated by using direct-acid-set cottage cheese whey containing increasing amounts of ethanol (0 to 5.4%) with decreasing amounts of sucrose (10 to 0%). Each decrease of 1 g of sucrose per 100 ml of whey accompanied by an increase of 0.54 g of ethanol decreased specific gravity 0.0046 unit and lowered the freezing point 0.159 H. Whey containing 10% added sucrose was treated as follows: (a) inoculated with Kluyveromyces fragilis, (b) carbohydrate splitting enzymes added and inoculated with K. fragilis and (c) carbohydrate splitting enzymes added and inoculated with Saccharomyces cerevisiae. All mixtures were incubated 48 h at 32 C during which six samples from each treatment were analyzed for total solids, specific gravity and freezing point. No difference (P>.05) was noted between samples treated with enzymes or those treated with the two yeasts cultures as related to decrease in total solids concentration or specific gravity. Each 0.001-H d...