The flavonoid content was determined as described by Zhishen et al. (1999) on triplicate aliquots of the homogenous juice (0.3 g). Fifty microlitre aliquots of the methanolic extract were used for flavonoid determination. Samples were diluted with distilled water to a final volume of 0.5 mL, and 30 mL of 5% NaNO2 was added. After 5 min, 60 mL of 10% AlCl3 was added and finally 200 mL of 1 M NaOH was added after 6 min. The absorbance was read at 510 nm, using a Cecil BioQuest CE 2501 spectrophotometer,
and flavonoid content was expressed as mg of rutin equivalents per kg of fw (mg RE/kg fw).