Determination of sugars, ethanol and glycerol in wine

Introduction

Rapid identification and quantitation of saccharose, glucose, fructose, ethanol, and glycerol in wines is still important. The determination of the sugar content is necessary to obtain the end point of the fermentation. Therefore these five compounds need to be analysed to control the quality and process of wine fermentation. This application note presents a simple and rapid method for the simultaneous determination of these target compounds.

HPLC and measurement conditions

This application was carried out on an AZURA Compact isocratic HPLC system equipped with degasser, autosampler, column oven, and refractive index detector. The Eurokat packing materials are sulfonated cross-linked polystyrene copolymers. The lead forms are the phase of choice for the separation of sugars and sugar alcohols. The separation behavior for the named analytes is based on ion exclusion and ligand exchange chromatography.Column:     KNAUER Eurokat Pb, 300 x 8 mm and 30 x 8 mm precolumn
Mobile phase:     water
Flow rate:    0.6 ml/min
Temperature:    60 °C

Sample preparation 

The wine sample can be injected directly after micro filtration and a 3:4 dilution with 2 mmol/l phosphate buffer pH 7.0. All standard solutions were prepared with double-distilled water.

Results

A calibration was made for saccharose, glucose, fructose, ethanol and glycerol. The calibration concentration was in the range between 1.5 to 75 mg/ml for each substance. The experimental data show that the linearity range is higher. All five substances are baseline separated. The linearity r² for all substances was better than 0.9999.

Figure 1: Chromatogram of baseline separated compounds in a standard solution of 75 mg/ml

Samples of young white wine (“Federweißer”) and red wine were analysed. The red wine was spiked with saccharose to show that saccharose can be analyzed in presence of wine matrix. The recovery rate was 99 %. The dilution of the samples with buffer is necessary, because the wine acids hydrolyse saccharose at 60 °C. This would result in a lower recovery rate

>> Download the full Application Note as PDF

Newsletters

Receive the latest pathologist news, personalities, education, and career development – weekly to your inbox.

I have read and understand the Privacy Notice*

Subscribe