Determination of SO2 and reducing sugars in Macedonian wines

Violeta Ivanova-Petropulos; Sasa Mitrev

Violeta Ivanova-Petropulos Faculty of Agriculture, University "Goce Delcev" - Stip, Republic of Macedonia
Sasa Mitrev Faculty of Agriculture, University "Goce Delcev" - Stip, Republic of Macedonia

Abstract

SO₂ acts as an effective antoxidant, preventing the activity of the oxidases and antimicrobial agent, showing a potential for bleaching the pigments and elimination of unpleasant odour in wines. Glucose and fructose are the main carbohydrates in grapes and wine, usually called reducing sugars. In this study, three titrimetric methods for determination of SO₂ (free and total) and reducing sugars in wines were checked. The linearity, accuracy and precision of the methods were confirmed using standard solution of SO₂ and reducing sugars (fructose and glucose) prepared in appropriate concentration range, as well as with low, medium and high concentrations. Additionally, the accuracy of the methods was confirmed by standard additions. Repeatability and reproducibility were confirmed with titration of real samples, analyzed with appropriate repetitions. Validated methods were applied for determination of the content of free and total SO₂, as well as reducing sugars in ten Vranec wines produced with different yeasts for fermentation.

References

Canals, R., Llaudy, M.C., Valls, J., Canals, J.M., Zamora, F. (2005). Influence of ethanol concentration on the extraction of color and phenolic compounds from the skin and seeds of tempranillo grapes at different stages of ripening, J. Agric. Food Chem. 53(10), 4019-4025.

Ivanova-Petropulos, V., Wiltsche, H., Stafilov, T., Stefova, M., Motter, H., Lankmayr, E. (2013). Multi-element analysis of Macedonian wines by inductively coupled plasma–mass spectrometry (ICP–MS) and inductively coupled plasma–optical emission spectrometry (ICP–OES) for their classification, Maced. J. Chem. Chem. Eng. 32(2) 265-281.

Ivanova V., Stefova M., Vojnoski B., Stafilov T., Bíró I., Bufa A., Felinger A., Kilár F. (2013). Volatile composition of Macedonian and Hungarian wines assessed by GC-MS, Food Bioprocess Tech. 6(6) 1609-1617.

Ivanova V., Stefova M., Vojnoski B., Dörnyei Á., Márk L., Dimovska V., Stafilov T., Kilár F. (2011). Identification of polyphenolic compounds in red and white grape varieties grown in R. Macedonia and changes of their content during ripening, Food Res Int. 44, 2851-2869.

Larue F., Park M. K., Caruana C. (1985). Quelques observations sur les conditions de la formation d’anhydride sulfureux en vinifi cation. Connaiss. Vigne Vin, 19, 241–248.

Liu S.-Q., Davis C. R. (1994). Analysis of Wine Carbohydrates Using Capillary Gas Liquid Chromatography, Am. J. Enol. Vitic. 45, 229.

Mayén M., Mérida J., Medina M. (1995). Flavonoid and nonflavonoid compounds during fermentation and post-fermentation standing of musts form Cabernet Sauvignon and Tempranillo grapes, Am. J. Enol. Viticult. 46, 255-261.

Vahl J.E., Converse J. E. (1980). Ripper procedure for determining sulfur dioxide in Wine: Collaborative study, J. Assoc Off Anal Chem. 63, 194-9.