Evaluation of aspects of grape polyphenol composition in an enological perspective

Flavonoids, and phenolics in general, are very interesting compounds, because of their reactivity, and their properties, with the consequent importance on health and food quality. They are a group of very similar compounds, but little differences are enough to change their role (as between anthocyanidins and flavanols). The situation is still more complicated when we consider polymers, or interactions, with the HPLC limitation on their evaluation. Many works have been done concerning these molecules, and in spite of their importance, a number of questions are still open for the researcher imagination. In my PhD thesis, I studied different aspects of flavonoid behavior in grape and wine: • concerning to anthocyanins, I made experiments related to: • evaluation of anthocyanins extractability by simulated maceration process: the influence of bunch exposure • copigmentation and anticopigmentation in grape extracts study by spectrophotometry and post column reaction HPLC Studying tannins, my experiments were related to: • preliminary study: grape tannins accumulation • seed phenolics oxidation: development of a new ripening index • proanthocyanidins polymerization: a different hypothesis