Effect of Browning on Total Phenolic, Flavonoid Content and Antioxidant Activity in Indian Gooseberry (Phyllanthus emblica Linn.)

Abstract

Browning of Indian Gooseberry (Phyllanthus emblica Linn.) for 4 hr caused significant (p<0.05) increase in total phenolic from 1,790.4 to 1,923.5 mg gallic acid equivalence/ 100 g fresh weight (FW) and in flavonoid content from 143.1 to 148.2 mg catechin equivalence/ 100 g FW. HPLC analysis
indicated that quercetin also increased significantly (p<0.05) from 2.8 to 3.4 mg/ 100 g FW after 4 hr of browning. While kaempferol was only found in the 6 hr browning sample (0.2 mg/ 100 g FW). Total antioxidant activity (TAC) as determined by ORAC method increased to 98.3 μmoles Trolox equivalence/100 g FW in 6 hr browning sample. It was shown that TAC had a good correlation with quercetin (r=0.711). In addition, TAC and quercetin exhibited high correlation with browning index of the Indian Gooseberry (r=0.720 and 0.977, respectively). Therefore quercetin, as flavonol compound, could represent changes in flavonoids as well as a good quality indicator for antioxidant activity (ORAC) in Indian Gooseberry.