Changes in Phenolic Compounds

For a long time, the dehydration of grapes for the production of raisins or for making either dessert or fortified wines, has been mainly considered as a process for increasing the sugar content of grape berries with little or no attention paid to the variation in other compounds induced by the modification of the cell metabolism accompanying the dehydration process. Most of the phenolic compounds found in Vitis vinifera L. are expected to play important roles in the quality of grape and wines. This chapter explains common methods, including high performance liquid chromatography (HPLC) and capillary electromigration techniques, for the analysis of phenolic compounds in grape berries, must and wine. Next, it discusses the influence of postharvest dehydration processes on the occurrence and concentration of phenolic compounds, either in the grape berries or in the must and wine. This edition first published 2013 © 2013 John Wiley & Sons, Ltd.