Determination of rheological behaviour of wine lees
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Department of Chemistry, Czech University of Life Sciences in Prague, Kamycka 129, 165 21 Praha 6 - Suchdol, Czech Republic
Department of Production and Power Engineering, University of Agriculture, Al. Mickiewicza 21, 31-120 Kraków, Poland
Department of Agricultural, Food and Environmental Engineering, Mendel University in Brno, Zemědělská 1, 61300 Brno, Czech Republic
Department of Horticultural Machinery, Mendel University in Brno, Faculty of Horticulture, Valtická 337, 69144 Lednice, Czech Republic
Department of Agricultural Engineering, University of Novi Sad, Trg Dositeja Obradovića 8, 21000 Novi Sad, Serbia
Publish date: 2015-08-03
Int. Agrophys. 2015, 29(3): 307–311
This study deals with the rheological properties of wine lees. Samples of wine lees of the Saint Laurent variety were used in this experiment. The investigated wine lees arose in the process of production red grape wine in 2013 (Czech Republic). At first, the chemical background was determined. The chemical background includes the following chemical parameters: total acidity, pH, alcohol content, reduced sugars, free SO2, total SO2, and volatile acid. In the second phase of the study, physical properties were determined. Specifically, a sample of wine lees was subjected to rheological tests. These tests consisted in determination of dependence of dynamic viscosity on the temperature, hysteresis loop tests, dependence of dynamic viscosity on the time and step-down in the shear rate test. The experiment demonstrated that the dynamic viscosity increased with increased temperature – this phenomenon is caused by thermolabile proteins – and the wine lees has rheopectic behaviour; the degree of rheopexy was found to rise with the increasing temperature.