Elution was performed with mobile phase A (5% formic acid in de-ionized
water) and mobile phase B (5% formic acid in acetonitrile/water
1:1 v:v); gradient expressed as mobile phase B volume was 20–
40% for 30 min, 40–50% in following five min and held at 50% for
10 min before returning to 20%. The flow rate was maintained as
1 mL/min and column temperature was 25 C. Detector performed
a full spectrum scan between 190–800 nm where 525 nm was
used for monitoring anthocyanins. Cyanidin-3,5-diglucoside was
used as an internal standard for quantitation of extraction recovery
and anthocyanin contents.