Influence of vinification stages for the acidity of Vitis labrusca wines

Abstract

Acidity is one of the most important parameters for sensorial profile of wines and is measured through the presence of organic acids, especially malic and tartaric acids, and of cations such as potassium. This study has used a high performance liquid chromatography methodology to evaluate the malic, lactic and tartaric acid concentrations in common wines elaborated with Terci grapes (Ives), to verify their influence in wine acidity and pH. Additionally, the potassium content was measured by spectrometry of atomic emission. The generated data were used in the principal component analysis (PCA) and in the determination of the correlation between the analyzed parameters. The occurrence of malolactic fermentation was able to alter wine composition leading to the separation of the samples in two clusters by PCA analysis. The overall samples presented acid characteristics, apart from the fact of completing malolactic fermentation. The correlation analysis made feasible the determination of the influence of malolactic fermentation in the wine acidity and pH, but no influence was noticed related to potassium and tartaric acid concentrations.