Sequential Injection System for the Enzymatic Determination of Ethanol in Wine

• Published in: Journal of agricultural and food chemistry 2006-01, Vol.54 (1), p.19-23
• Main Authors: Páscoa, Ricardo N. M. J, Vidigal, Susana S. M. P, Tóth, Ildikó V, Rangel, António O. S. S
• Format: Article
• Language: English
• Subjects: alcohol dehydrogenase; Alcohol Dehydrogenase - metabolism; Biological and medical sciences; enzyme activity; ethanol; Ethanol - analysis; Fermented food industries; Flow Injection Analysis - methods; food analysis; Food industries; fortified wines; Fundamental and applied biological sciences. Psychology; Hydrogen-Ion Concentration; NAD - analysis; red wines; sequential injection analysis; spectrophotometers; Spectrophotometry; white wines; Wine - analysis; wines; Wines and vinegars
• ISSN: 0021-8561; 1520-5118
• DOI: 10.1021/jf051787l

A sequential injection system was developed for the enzymatic determination of ethanol in wine. The spectrophotometric determination is based on the enzymatic reaction catalyzed by alcohol dehydrogenase in the presence of NAD+. The system was applied to the determination of ethanol in a range of 0.008−0.024% (v/v) with good repeatability; RSD n =10 < 2.3%. The results obtained with the developed system showed good agreement with those obtained by using the reference method. The determination rate was 25 h-1; 1 μmol of NAD+, 1.1 units of enzyme, and 50 μL of sample were consumed per determination; and the waste produced was 2.2 mL per assay. Keywords: Sequential injection analysis; alcohol dehydrogenase; ethanol; wine; spectrophotometry