when the values of maluod were excluded; the linear
regression correlation increased to 0.973. The results
indicated that in some fruits for e.g. maluod, the
antioxidant activity is not mainly contributed by phenolic
compounds.
At present, there is no information on the recommended
intake level for total antioxidant activity and phenolic
compounds. Prior et al. (1998) estimated the normal intake
of antioxidants by measuring the antioxidant activity in
foods consumed by the American people using the ORAC
method. A range of 1200–1700 mmol TE/day was reported.
A normal intake of approximately 1000mg GAE/day of
total phenolic compounds was estimated by Scalbert and
Williamson (2000). According to the Thai FBDG, Ministry
of Public Health (1999), the recommended amount of fruits
consumed per day should be about 250 g; therefore, the
studied common fruits could provide an average of
3230 mmol TE/day of ORAC antioxidant activity and
200 mg GAE of total phenolic compounds. The studied
indigenous fruits—makiang and maluod—which are normally
consumed as beverages (25% and 40% concentration,
respectively), contribute 820 and 1120 mmol TE of
ORAC antioxidant activity and 74 and 98 mg GAE of total
phenolic compounds per 200mL serving, respectively
(unpublished data). This study confirms that fruits are
excellent sources of antioxidants.