Determination of anthocyanins, flavonoids and phenolic acids in potatoes. I: Coloured cultivars ofSolanum tuberosum L

Abstract

The major anthocyanins, flavonoids and phenolic acids in the tubers (skin and flesh), flowers and leaves of 26 cultivars of Solanum tuberosum L with coloured skins and/or flesh have been identified and quantified using analytical HPLC. Red tubers contained mostly pelagonidin-3-(p-coumaroyl-rutinoside)-5-glucoside (200–2000 μg g−1 FW) plus lesser amounts of peonidin-3-(p-coumaroyl-rutinoside)-5-glucoside (20–400 μg g−1 FW). Light to medium purple tubers contained petunidin-3-(p-coumaroyl-rutinoside)-5-glucoside (1000–2000 μg g−1 FW) plus small amounts of malvidin-3-(p-coumaroyl-rutinoside)-5-glucoside (20–200 μg g−1 FW) whilst dark purple–black tubers contained similar levels of petunidin-3-(p-coumaroyl-rutinoside)-5-glucoside together with much higher concentrations of malvidin-3-(p-coumaroyl-rutinoside)-5-glucoside (2000–5000 μg g−1 FW). Tuber flesh also contained chlorogenic acid (30–900 μg g−1 FW) and other phenolic acids plus low concentrations of flavonoids (0–30 μg g−1 FW). Tuber skins showed much higher levels (1000–4000 μg g−1 FW) of chlorogenic acid. The major anthocyanins in flowers were present as the rutinosides or other glycosides of pelargonidin, petunidin and malvidin whilst glycosides of cyanidin and delphinidin were found in some flowers, together with many of the same phenolic acids as found in tubers. The commonest flavonoids included rutin, kaempferol-3-rutinoside and two quercetin-rhamnose-glucosides. Flowers and leaves contained higher concentrations of flavonoids which fell into two patterns, with some cultivars containing high concentrations of quercetin-3-glycosides, whilst others had much lower concentrations. © 1998 SCI.