| Abstrak/Abstract |
Background and Objective:
Purple yam (
Dioscorea alata
L.) is a potential source of natural antioxidants due to its re
latively high
anthocyanin content. Anthocyanin is a natural source of antioxi
dants, acting as a free radical scavenger with a role in aging, cancer and
degenerative illness prevention. Using a variety of solvents an
d acids, this study aimed to extract purple yam flour anthocyanins with high
antioxidant activities.
Methodology:
Anthocyanins were extracted using methanol and ethanol-based
solvents that were acidified with
hydrochloric acid (HCl), citric acid or tartaric acid. The resu
lting extracts were assayed for anthocyanin and total phenolic
contents,
antioxidant activity (expressed as % radical-scavenger activity
[%RSA]) and ferric reducing antioxidant power (FRAP). All data
were
analyzed using one-way analysis of variance. The differences we
re analyzed using Duncan’s multiple range test. The p<0.05 was
considered significant. Pearson’s correlation coefficient analy
sis among anthocyanins, total phenolics contents and antioxidant activities
were calculated using Microsoft Excel, 2007.
Results:
Results showed that the methanol/HCl (MeH) solvent could be us
ed to extract
anthocyanin from purple yam flour more thoroughly than other so
lvents. Total phenolic contents were not significantly differen
t between
MeH and methanol/tartaric acid (MeT) extracts (5.18 mg GA/100
g extract). Antioxidant activities of MeH and MeT anthocyanin e
xtracts
were not significantly different (69.87% RSA and FRAP of 50.27
?mol
g
ferro L
G
1
). Anthocyanin and total phenol contents correlated
significantly with RSA and FRAP.
Conclusion:
This study suggested that anthocyanins and phenols purple yam
flour are an abundant
natural antioxidant sources, while the best solvent for the extraction was an acidified polar solvent. |
