Anthocyanin derivatives and tannins of red wine by hplc-dad-ms/ms. Evolution along winemaking and comparision between rioja and bordeaux wines

Resumo

Anthocyanins and flavanols play an important role in the quality of wine contributing to sensory aspects such as colour, astringency or bitterness and they can also help in the differentiation between grape varieties and growing conditions of the grapes.In this work, 18 new anthocyanin derivatives, which are formed by direct condensation of anthocyanin with two units of flavanols, have been identified by HPLC-DAD-MS/MS. Moreover, the detection conditions for 22 compounds, some of them identified in previous works, have also been optimized.On one hand, the formations and evolutions of different anthocyanin derivatives and tannins during different stages of winemaking have been studied. It can be seen that the formation of anthocyanin derivatives starts quickly as anthocyanins are being extracted from grape. In contrast, the extraction and formation of tannins occurs slower than anthocyanins and anthocyanin derivatives.On the other hand, 196 samples were analyzed by HPLC-DAD-MS/MS in order to compare wines from different region (Rioja and Bordeaux). Some significant differences between red wines have been found, as consequence of different grape varieties used in each region. However, major differences are due to the different wine styles within each region, mainly related with the extension of time ageing. In addition, the information obtained in this work in relation to the composition of anthocyanins, anthocyanin derivatives and tannins of Rioja and Bordeaux wines has allowed us to carry out a PCA study for the differentiation of wines from different regions or styles.