Why does the combination of molasses and yeast cause fementation?

Question

the combination of molasses and yeast causes fermentation; therefore since molasses is composed of the three sugars sucrose, glucose, and fructose it could be assumed that one of the three sugars would ferment with yeast; however, none produce a reaction. Therefore, what is in molasses that causes fermentation with yeast.

Answer 1

The use of molasses as a substrate for ethanol production by the thermotolerant yeast Kluyveromyces marxianus var. marxianus was investigated at 45°C. A maximum ethanol concentration of 7.4% (v/v) was produced from unsupplemented molasses at a concentration of 23% (v/v). The effect on ethanol production of increasing the sucrose concentration in 23% (v/v) molasses was determined. Increased sucrose concentration had a similar detrimental effect on the final ethanol produced as the increase in molasses concentration. This indicated that the effect may be due to increased osmotic activity as opposed to other components in the molasses. The optimum concentration of the supplements nitrogen, magnesium, potassium and fatty acid for maximum ethanol production rate was determined using the Nelder and Mead (Computer J 7:308-313, 1965) simplex optimisation method. The optimum concentrations of the supplements were 0.576rg l-1 magnesium sulphate, 0.288rg l-1 potassium dihydrogen phosphate and 0.36% (v/v) linseed oil. Added nitrogen in the form of ammonium sulphate did not affect the ethanol production rate.

Answer 2

Sucrose & glucose usually are fermentable with yeast but the concentration can not be too high. Perhaps trace elements in the molassis help "feed" the yeast.

Answer 3

molasses is a preservative

Answer 4

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