3.4. Free radical scavengin g activity and antioxidant capacity
Results of our study showed that the sonication significantly
(P < 0.05)improved the DPPH free radical scavenging activity of
apple juice (Table 2). The percent inhibition of DPPH free radical in-
creased from 39.71 up to 43.38 and 46.94 in all the samples soni-
cated for 30, 60 and 90 min,respectively , as compared to that
(32.87) of control (non-sonicated)sample.We also observed the
significantincrease (P < 0.05)in total antioxidant capacity of all
the samples sonicated for 30, 60 and 90 min ranged from 324.57
up to 353.85 and 363.05 lg ascorbic acid/g as compared to non-
sonicated sample which were 299.64 lg/g of ascorbic acid equiva-
lent. The increase in antioxidant capacity might be attributed to
the increase in ascorbic acid and polyphenol ic compounds in the
apple juice due to the cavitations produced during sonication
which increased the extractio n and availability of these com-
pounds. More the polyphenoli c compound s more the antioxidant
capacity will be. Being antioxidant s, these compounds play amajor