method were found in most of the studied fruits except
those of papaya, banana and maluod (with a linear
regression correlation of R ¼ 0.711 between ORAC and
FRAP for all the studied fruits). It is likely that not all
ORAC-active antioxidants in the studied fruits are reducing
agents (detected by FRAP). The rank of ORAC
antioxidant activity values in fruits was makiang4maluod4
mangosteen4ripe mango (nam-dok-mai)4guava4unripe
mango (kiew-sa-weya)4papaya4banana. The rank of
FRAP antioxidant activity values in fruits was not similar
to the ORAC values: maluod4makiang4guava. The
others contained low levels, 4–8 mmol TE/g, of FRAP
antioxidant activity. It is not surprising that a different
ranking order of antioxidant activity among the studied
fruits was shown by ORAC compared to the FRAP
method because in theory the measurement of each method
is based on different mechanisms of reaction (Benzie and
Strain, 1996; Prior and Cao, 1999). Therefore, the
antioxidant activity should be investigated by more than
one method (Aruoma, 2003). As with papaya, a low
level of antioxidant activity—analysed by both ORAC and
FRAP methods—was found in banana, which agreed
well with the values reported by Wang et al. (1996),
2.6 and 2.2 mmol TE/g, respectively, whereas Wu et al.
(2004a) reported a higher value. No data of antioxidants in
other studied fruits are available in the literature for
comparison