Occurrence and Significance of Quercitol and Other Inositols in Wines during Oak Wood Aging

Abstract

Inositols (quercitol, <i>chiro</i>-inositol, <i>scyllo</i>-inositol, and <i>myo</i>-inositol) were analyzed in commercial wines, in samples of experimental wines, in wines aged in oak barrels from different origins and with different time of usage, and in oak chip-treated wines. <i>chiro</i>-Inositol and quercitol were documented for the first time in wine. <i>chiro</i>-Inositol seemed to be a component arising from grapes, together with other cyclitols such as <i>myo</i>-inositol and <i>scyllo</i>-inositol, whereas quercitol was only found in oak-aged wines. <i>chiro</i>-Inositol was not detected in some commercial wines, indicating that the amount of this cyclitol could change with grape variety. The concentration of quercitol increased with aging time and depended on the age and characteristics of the barrels, but not on the grape variety used. For the other cyclitols, aging in oak barrels did not appreciably modify the concentration in each batch. In oak chip-treated wines, quercitol was also present and its concentration was influenced by chip size. Quercitol seems to be a potential new indicator of the contact of wine with oak wood.