STUDY ON THE EVOLUTION OF MICRO- AND MACROELEMENTS DURING THE WINEMAKING STAGES: THE IMPORTANCE OF COPPER AND IRON QUANTIFICATION

摘要

Knowledge of the concentration of mineral elements from winemaking products, particularly from the final product is important because of their influence on wine quality. Some metal ions such as iron and copper can induce haze formation and changes in the sensory proprieties of wine. The presence of heavy metals in wine is due to different factors including vineyard soil, agricultural practices (the use of fertilizers and pesticides), and can be at the same time a result of environmental pollution. In addition, the acidity of wine and grape must (freshly pressed grape juice) can dissolve Cr, Cu, Ni, and Zn from winemaking equipment like pumps and taps. As wine is the most widely consumed alcoholic beverage, analytical control of mineral elements content is required during the whole process of wine production, from the grapes used to the final product. In this study the content of micro- and macroelements in grape pomace, yeast sediment, grape must and wine was determined by inductively coupled plasma-mass spectrometry (ICP-MS). Samples of winemaking products originating from five grape varieties were analyzed in four forms in order to determine to what measure the values varied the PCA (Principal component analysis). The obtained results using PCA highlighted major differences in the content in trace elements between samples.