ELABORATION OF A METHOD TO DETERMINE THE DRY WHITE WINE FALSIFICATION WITH SUCROSE

Abstract

A standard method of reducing sugars determination using Fehling-Muller reagent has been modified and applied to control the presence of sucrose in white dry wine that can be considered as an indication of its falsification. Natural dry wine should not contain any significant amounts of sucrose since its content in regular grape is below 0.9 wt % and it would be fermented almost completely in the course of wine maturing and manufacturing. However, some sucrose can be added by fraudulent producers to the source wine materials in order to accelerate its fermentation. This results in a higher content of residual sucrose in dry wine that can exceed its maximum permissible level of 4 g/l. The modified method of the reducing sugars determination has shown good durability and reproducibility and can be used to determine the residual sucrose concentration above 1.33 g/l. However, excessive sulfites and other reducing preservatives present in some wines (especially in the low-grade samples) can distort the analysis results and should be removed in advance. Potentially, this method can also be applied to analyze wine blending samples and to control their affinity by the ratio between reducing and non-reducing sugars contents.