Determination of ethanol in whey-sugar solutions by freezing. [Kluyveromyces fragilis and Saccharomyces cerevisiae]

Journal Article · Fri Jan 01 04:00:00 EST 1982 · J. Food Prot.; (United States)

OSTI ID:6467960

Demott, B J

The composition of solutions undergoing yeast fermentation was stimulated by using direct-acid-set cottage cheese whey containing increasing amounts of EtOH (0 to 5.4%) with decreasing amounts of sucrose (10 to 0%). Each decrease of 0.54 g EtOH decreased specific gravity by 0.0046 unit and lowered the freezing point by 0.159 H (the Hortvet unit). Whey containing 10% added sucrose was treated as follows: (a) inoculated with Kluyveromyces fragilis, (b) carbohydrate splitting enzymes added and inoculated with Kluyveromyces fragilis and (c) carbohydrate splitting enzymes added and inoculated with Saccharomyces cerevisiae. All mixtures were incubated 48 h at 32 degrees during which 6 samples from each treatment were analyzed for total solids, specific gravity and freezing point. No difference was noted between samples treated with enzymes or those treated with the 2 yeasts cultured as related to decrease in total solids concentration or specific gravity. Each 0.001 H decrease in freezing point was accompanied by a total solids decrease of 0.006 g/100 g whey in the nonenzyme treated sample, and 0.008 g and 0.010 g/100 g whey in the enzyme-treated samples inoculated with Kluyveromyces fragilis and Saccharomyces cerevisiae, respectively. Each 0.001 H change in freezing point was equivalent to a change of 0.00003 specific gravity unit in the nonenzyme-treated sample and 0.000043 and 0.000048 specific gravity unit in the enzyme-treated samples inoculated with Kluyveromyces fragilis and Saccharomyces cerevisiae, respectively. The precision with which freezing point can be determined suggests its use in evaluating the amount of EtOH produced during fermentation.

• Research Organization: Dept Food Technol Sci, Univ Tennessee, Knoxville, TN 37901
• OSTI ID: 6467960
• Journal Information: J. Food Prot.; (United States), Journal Name: J. Food Prot.; (United States) Vol. 45:1; ISSN JFPRD
• Country of Publication: United States
• Language: English

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ALCOHOLS
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ENZYMES
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FUNGI
HYDROXY COMPOUNDS
INDUSTRIAL WASTES
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THERMODYNAMIC PROPERTIES
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WASTES
WHEY
YEASTS