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Antioxidant and
antimicrobial activities of extract and essential oil of
korarima
(Aframomum
corrorima (Braun) P.C.M. Jansen)
S. Eyob1*, B. K. Martinsen2,
A.
Tsegaye3,
M. Appelgren1 and G. Skrede2
1Norwegian
University of Life Sciences, Department of Plant and
Environmental Sciences, P. O. Box 5003, NO-1432 Ås, Norway.
2Nofima
Food, Matforsk AS, Food, Fisheries and Aquaculture Research,
Norway, Osloveien 1, NO-1430, Ås, Norway.
3Hawassa
University, P. O. Box 5, Awassa, Ethiopia.
*Corresponding author. E-mail:
solomon.eyob@umb.no.
Tel: +4764966139. Fax: +47 64965615.
Accepted 23 June, 2008 |
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The antioxidant potential of extracts and essential oils of
korarima (Aframomum corrorima (Braun) P.C.M. Jansen) were
investigated, as well as total phenolics, total ascorbic
acid (TAA), condensed tannins (CT) and antifungal potential.
Antioxidant capacities of seeds and pods as assayed in
methanol
extracts, and of essential oils
were at moderate levels.The antioxidant activity of seeds (29.59
µmol/g dry weight (DW))
was
significantly
higher than
that of pods
(14.23 µmol/g DW) by FRAP
(Ferric
Reducing Ability of Plasma)
assay. Also the
antiradical power of seeds (9.26
µmol/g DW)
was higher than of pods (3.08
µmol/g DW)
in the DPPH
(1,1-diphenyl-2-picrylhydrazyl)
test.
Similarly, the
antioxidant activity of seeds was higher than of pods in the
β-carotene
bleaching test.
A
lower 50%
effective concentration (EC50) was achieved with
seeds (42.10 mg/mL) as compared to pods (120.50 mg/mL),
while EC50 of pod oils (11.9 mg/mL) was lower
than seed oils (59.2 mg/mL).
The total phenolic content in seeds
(3.98 mg/g DW)
was significantly higher than in pods
(1.32 mg/g
DW),
while TAA content was significantly lower in seeds (3.49
mg/100 g DW) than in pods (6.25 mg/100 g DW). Differences in
CT were non-significant. Antifungal tests exhibited that the
extracts from seed were more effective than the control.
Based on the present study the consumption of korarima as a
spice may be used as source of antioxidants.
Key
words:
Zingiberaceae, Aframomum corrorima, korarima,
extract, essential oil, antioxidant,
antiradical and antifungal. |
