The aim of the master's thesis was to determine whether an enzymatic method for alcohol reduction in wine can be used to obtain wine with an alcohol content of less than 0.5 % vol. In the experiments, the enzymes glucose oxidase and catalase were used to break down glucose in apple juice and grape must. Eight different samples were used, six samples of grape must and two samples of apple juice. The enzymes show optimal activity within a certain temperature range and pH value. Grape must and apple juice have a lower pH than required for enzyme activity. For this reason, we increased the pH of some samples. Before the enzyme reaction, we measured the glucose concentration of the samples. After 20 hours of enzyme treatment at 24 °C, we measured the glucose concentration again to determine how much it had been degraded by the enzyme. We then carried out the fermentation of the samples. After fermentation, the samples were sent for WineScanTM analysis, which we used to compare the physico-chemical parameters of the samples before and after fermentation. Finally, we carried out a sensory evaluation based on a descriptive analysis. Samples with added enzymes were found to have higher levels of gluconic acid, one of the degradation products of glucose. Samples whose initial pH was increased by the enzymatic reaction were sensory less acceptable. With the chosen method, we did not achieve the desired reduction of the alcohol content in the wine, since the results were below expectations. The results confirmed our hypothesis that sensorically acceptable non-alcoholic wine cannot be obtained by an enzymatic process and reject the hypothesis that enzymatic activity is influenced by temperature and pH.
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