Validation of an Automated Enzymatic Method for the Determination of Fermentable Sugars in Wines

Abstract

[Abstract] An automated enzymatic method based on hexokinase/glucose-6-phosphate dehydrogenase reactions was validated for the determination of sugar content, expressed as the sum of glucose and fructose, in wines. The linearity of the calibration curve was excellent (R2 = 0.9998), and the LOQ (0.13 g L−1) was adequate for the determination at levels acceptable for the characterisation of wine types. The precision and accuracy were evaluated with six reference materials, providing highly successful results (RSD < 3.5% for precision and R2 = 0.9993 of correlation between the obtained and declared values). The method was applied to the analysis of 18 commercial samples of wines from Galicia meeting the commercial content required. Finally, the results found were compared to those obtained by the high-performance liquid chromatographic reference method of the International Organisation of Vine and Wine, showing a good correlation (R2 = 0.9943).