Evaluation of a Digital Blood Glucose Monitor for Measuring Residual Glucose in Wines

Abstract

Current methods for accurately measuring residual sugar (RS) concentrations in wine can be time-consuming, requiring multiple preparation steps and careful training. Sugar test pills and strips are rapid and easy to use for monitoring RS concentrations from 1 to 20 g/L but only give an approximate RS concentration. Recently, hand-held, digital glucose testing monitors have become available for use by diabetics to accurately and rapidly monitor blood glucose concentrations. We evaluated one of these monitors for its sensitivity and accuracy in model wine solutions. Wines of varying RS concentrations were tested and the results compared to standard procedures. The influence of pH and ethanol and SO₂ concentrations on the assay were investigated. The monitor showed promise for measuring glucose concentrations of 1 g/L or less in wines. In model wine solutions, a nonlinear response was obtained with glucose concentrations of 2 to 10 g/L. The evaluated type of system is not suitable for routine monitoring of fermentations in a winery.