Total flavonoids content (TFC)
Fig. 4 shows that the methanol extracts had higher activity than the water extract. The mean values of methanol and water extracts expressed as mg rutin/g ranged from 6.99 to 7.98 and from 6.54 to 6.86 for PPE inside of, outside, whole part oven dried peels, while those dried by solar energy, gave mean values that ranged from 6.96 to 7.96 for methanol extract, and from 6.32 to 6.86 for water extract for inside, outside, whole part of PPE. The PPE possess proton donating ability and in association with a number of hydroxyl groups in the TFC structures to stabilize free radicals it could due to their ability to quench hydroxyl radicals by transferring hydrogen atom to free radical (Moussaid et al., 2011).