Kinetics of Formation of Flavano-C-Glycosidic Ellagitannins (Acutissimin A and B) in Model Solutions Containing Medium Toasted Oak Chips and Catechin for Wine Aging

The aging process of wine goes beyond conservation and involves the use of wood, which is capable of containing and protecting, and allows a limited passage of oxygen, sufficient to promote slow maturation of the wine, thanks to which it reaches the maximum of its organoleptic qualities. The most used wood is oak and during aging, the wine extracts from the wood of the barrels an abundant quantity of aromatic substances, due to the contact between the wine and the matrix of the wood. Among the newly formed compounds, the flavano-ellagitannins, namely the acutissimin A and B, are the minor compounds found in wood aged wine. They are formed during the aging process through the condensation of tannins, such as vescalagin, extracted from the wood matrix and flavonoids, such as catechins contained in wine. The aim of the study is to verify the formation of acutissimins after 28 days in model solutions that simulated aged wine in the presence of 1%, 5%, and 10% w/v percentages of wood chips obtained from Quercus alba and with variable concentrations of catechin (100 and 500 mg L−1). The formation of compounds, including acutissimin A and B, and the disappearance of catechin are identified by high-performance liquid chromatography/electrospray ionization/mass spectrometry. Acutissimins A and B are validated by comparison with the characteristic m/z reported in the literature. Based on the results obtained, the model system prepared with 500 mg L−1 of catechin and 10% w/v oak chips showed the highest content of acutissimin A and B