To determine composition, anthocyanins were extracted and separated in a PR-18 column as described by Markham and Ofman [26], and hydrolyzed by boiling in 2 N HCl for 1 h. Anthocyanidin composition was determined using an HPLC (Shimatzu, Japan) equipped with an LC-10AT pump, a SCL-10A controller and a SPD-M10AVP photodiode-array detector.