Knowing our local wines: chemical profiling

Wine is mainly consumed and appreciated for its sensory attributes which are due to a complex combination of several compound classes. In the overall assessment of the sensory characteristics of a food, and particularly of a wine, volatile molecules play a fundamental role, being recognized as the major contribution to the food flavor. Likewise, also polyphenols are strictly related to the sensory characteristics, being associated to the taste and to the color of the product. Furthermore, polyphenols content of red wines has also been invoked in the explanation of the French paradox, being demonstrated that their intake is associated with a low incidence of coronary heart diseases. Thus, aiming at the valorization of local food products, we have studied the composition of a local wine1,2 investigating some of the most important chemical molecules contributing to the flavor and to the beneficial effects associated with the consumption of red wines, in order to widen the knowledge on this beverage that has been only partially investigated in the past.3 We have developed and applied a HS-SPME-GC-MS/FID method to identify and quantify the volatile compounds. Among the most abundant molecules detected (esters, alcohols, phenols, hydrocarbons, organic acids), eleven compounds have been quantified. The determination of phenolic compounds, i.e. gallic acid, p-coumaric acid, trans-ferulic acid, caffeic acid, trans-resveratrol, (+)-catechin and (-)-epicatechin, was performed by using HPLC-ESI-MS with direct injection of wine samples. Both volatiles and polyphenols have been quantified in wines produced from the different harvest years and having different aging before the third fermentation. Results will be presented and discussed.