Extracts were loaded on to a PR-18 column (Vydac 201TP54) and separated with the following solutions: 1.5% aq. H3PO4 and H2O/MeCN/HOAc/H3PO4 (107:50:40:3), applied as a linear gradient from ratios of 7:3 to 1:4 over 45 min, and held at a 1:4 ratio for an additional 10 min at a flow rate of 0.8 ml min1. Anthocyanidins were identified by comparing both the retention time and the absorption spectrum from 250 to 650 nm to those of standard purified anthocyanidins.