Different SO₂ Doses and the Impact on Amino Acid and Volatile Profiles of White Wines

SO₂ is a preservative often used in the food industry, particularly in the wine industry. However, regulatory authorities and consumers have been strongly suggesting its reduction or even its replacement. In order to understand the impact of SO₂ on the profiles of volatile organic compounds (VOCs) as well as amino acids (AAs), the aging of two white wines (one being a varietal and another being a blend) under identical conditions and in the presence of different doses of total SO₂ was studied. After alcoholic fermentation (t = 0), either no SO₂ was added (0 mg/L), or 30, 60, 90, or 120 mg/L of SO₂ was applied. The samples under study were kept on fine lees for 3 months (t = 3). After 3 months (t = 6) and 9 months (t = 12), the wines were bottled and analyzed. For t = 0 and t = 3, the samples were submitted to HS-SPME-GC/MS for VOC analysis and LC-DAD for AA analysis. From the principal component analysis of the detected VOCs, it was observed that the blended wine in comparison with the varietal wine, was less impacted by the applied SO₂ doses and aging time. From the AA profile, it was also observed in this study that maturation on fine lees resulted in an increase in the total concentration of AAs as would be expected.