Barrel-to-barrel variation of phenolic and mineral composition of red wine

Abstract

The aim of the present work was to evaluate the effect of barrel-to-barrel variability on chemical characteristics of red wine. An experimental trial was carried out involving two red wines from the Portuguese DO Dao and independent replicates of French oak barrels (Quercus sessiliflora Salisb.) from three different cooperages. After six months of aging, comprehensive chemical characterization of the wines took place: general physical-chemical analysis by FTIR, phenolic composition and chromatic characteristics, major mineral elements (K, Mg, Ca, Na, and Fe) by flame atomic absorption spectrometry (FAAS), minor and trace elements (Li, Be, Ti, Mn, Co, Ni, Cu, Zn, Ga, As, Rb, Sr, Y, Zr, Nb, Mo, Cd, Sn, Sb, Cs, Ba, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, W, Tl, Pb, and U) by inductively coupled plasma mass spectrometry (ICP-MS). In respect to barrel effect, significant differences between replicates were observed for phenolic composition, especially polymerized pigments, flavonoids and color intensity. Regarding major, minor and trace elements, no significant differences were observed between barrel replicates with exception of iron and copper.