Full Professor in the Department of Chemistry and Biochemistry (DQB) in the University of Porto. He obtained his PhD in Biological and Medical Sciences in the University of Bordeaux II (France), specialization in Oenology. Member of the REQUIMTE-LAQV Research Centre, and he is the leader of the Food Polyphenol Lab where he has been developing an independent research area. Victor Freitas presents in his CV more than 230 original articles published in journals indexed in the Science Citation Index (SCI), several book chapters, numerous invited conferences, running multiple I&DT projects and several supervisions of Master and PhD students.

(http://www.foodphenolab.com)

• http://orcid.org/0000-0003-0586-2278

Title: Port wine colour: a quick glance

Abstract: The wide range of colours perceived everywhere in nature has always fascinated the humankind, in particular the colour of plants and foodstuffs … and wine is not an exception. In fact, wine colours have inspired the painters not only to paint wine motives, but also to use wine as a dye in their paintings. Beside these ludic activities, the colour of wines and especially the red ones has always attracted the attention of consumers and hence constitute a positive attribute in terms of product quality. The colour of Port wine is somehow unpredictable in time because changes continuously during its life. Indeed, Port wines is particularly rich in different colour hues from the yellow pale of white wines to the orange/yellow-brown colour of old Ports (townies and vintages), passing through the deep red and purple colours of young vintages.

The expression of the colour in red wines depends not only on the anthocyanin concentration (grape skin pigments) but also on physical and chemical phenomena that occur in wine during ageing. All these phenomena occur concomitantly leading to the transformation of genuine anthocyanins into other pigments (e.g. bluish “portisins”) that are characteristic of Port wines thus contributing to their chromatic identity. The winemaking conditions employed such as the maceration techniques, fermentation (yeast strains, temperature, etc.), wine spirit quality, oxygenation and many others may affect importantly the formation of these pigments and the final Port wine colour.