Antioxidant activity of the peels of guava, papaya and pineapple / Labibah Abdullah

The antioxidant activity of the peels of guava, papaya and pineapple was evaluated by 2,
2 – diphenyl -1- picrylhydrazhyl (DPPH) method. This study was carried out to
determine the total phenolic content (TPC) of these peels of fruits. For this testing,
ethanol and water was used as extracting solvent. The total phenolic content of the
crude extract of peels were determined from the standard calibration curve of gallic
acid. From the results, it showed that the ethanol extract had higher total phenolic
content than the water extract for all of fruits peel extract. In guajava psidium, value of
ethanol extract is (1210 mg GAE/g ) compared water extract (324 mg GAE/g), carica
papaya (353.2 mg GAE/g) for ethanol extract compared to water extract is (102.4 mg
GAE/g) and also for ananas comosus with ethanol extract (236.4 mg GAE/g) compared
to water extract (80 mg GAE/g). Ethanol extract also showed the higher radical
scavenging for all of fruits peel. For guajava psidium, ethanol extract showed (98.4 %)
compared to water (76.9%). While for radical scavenging activities of carica papaya in
ethanol extract was (83%) compared water extract was (82.7%). Ethanol extract of
ananas comosus peel also showed higher scavenging activities with (76.1%) compared
to water extract was (73.3%). From the testing on 2, 2 – diphenyl- 1- hydrazhyl (DPPH)
method, it showed that the extract of guajava psidium had high radical scavenging
acivities and also had high total phenolic content .