The distribution and content of anthocyanins in young port wines as determined by high performance liquid chromatography

Abstract

The distribution and content of anthocyanins in young port wines made in three successive years (1981–1983) from up to sixteen grape cultivars grown at five different sites in the Douro Valley in Northern Portugal has been assessed by high performance liquid chromatography. Distributions are confined to the seven most readily separated and identified anthocyanins and expressed as percentages of their sum (78–97% of the total integrated area). Anthocyanins based on malvidin (Mv) predominated (57–94%). Of these Mv 3‐glucoside was the major pigment (43‐76%), followed usually by Mv 3‐p‐coumarylglucoside (1–38%) and then Mv 3‐acetylglucoside (2–18%). Peonidin 3‐glucoside (2–39%) was prominent in a few cultivars but delphinidin 3‐glucoside (1–13%), petunidin 3‐glucoside (2–12%) and cyanidin 3‐glucoside (trac‐4%) were of low proportions throughout. The ratio Mv 3‐acetylglucoside/total Mv glucosides appeared characteristic of cultivar, independent of site and a useful aid to identification. The percentages of Mv 3‐p‐coumarylglucoside were usually lower in ports than in grape skin extracts of the same cultivars. The contents of total anthocyanins in the ports ranged from 143–1080 mg 1⁻¹ (expressed as malvidin 3‐glucoside chloride) and varied according to site and season.