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Temperature and Glycerol Formation: A Proposal to Explain the Causal Relationship Based on Glycolytic Enzyme Activities

2019-04-01
Buyukkileci, Ceylan
Batur, Aysem
BÜYÜKKİLECİ, ALİ OĞUZ
Hamamcı, Haluk
Most yeast strains produce glycerol in larger quantities when cultivated at higher temperatures, which likely explains why red wines contain higher amounts of glycerol than white wines. In this work, we used a kinetic and thermodynamic approach to suggest a mechanistic explanation for this phenomenon. We began with a glycolytic model of the kinetics of the individual enzymes. The effects of temperature and ethanol on the apparent kinetics of individual enzymes were then determined and incorporated into the model. The activation energy for each enzyme was determined with the Arrhenius equation. The enzymes in the upper part of the glycolytic pathway were found to be more dependent on the temperature than those in the lower part. The model, as improved by these changes, could qualitatively simulate the ethanol and glycerol production curves and the production of more glycerol at higher temperatures. We propose that the differences in the temperature dependence of the enzymes around the glycerol branch are the reason for glycerol accumulation at higher temperatures.