Authors
Title
Abstract
The objective of the study was to assess the usefulness of enzymatic method and analytical „Alkotest” kit applied to perform a quantitative analysis of the ethanol content in wines, fruit drinks and juices, meads, and non-alcoholic beer. Based on the assessment results obtained, the usefulness of the enzymatic method was proved as regards its application in determining the ethanol content in the products under analysis. The method used is considerably less expensive compared to other enzymatic methods because of the low costs of alcohol oxidase preparation (AO) produced from a ‘Hansenula polymorpha C-105 (gcr 1 catX)’, a mutated methylotrophic yeast strain with the disturbed catabolic repression of the AO synthesis. It was proved that the different chemical compositions of fruit wines and juices slightly impacted the determination of the content of alcohol therein. Based on the comparison of the „Alkotest” method and its modified „Multiple Addition Test” version, it was possible to state that there was no significant negative effect of components contained in fruit wines on the determination results of the ethanol concentration. The application of the „Multiple Addition Test” and Gas Chromatography (GC) methods confirmed the above conclusion. The results achieved from comparing the two methods were comparable, and the correlation coefficients amounted to, respectively, 0.997 at p < 0.0001 for red fruit wines and 0.998 at p < 0.0001 for white fruit wines.
Keywords
alcohol, alcohol oxidase, fruit wines, fruit drinks, juices