Abstract:
Capsicum annuum L. (Solanaceae family) is one of the common peppers that are used as spices
to flavor dishes and consumed as a vegetable. Peppers contain many bioactive compounds most
of which are related to antioxidant activity. The major bioactive constituents as well as the major
determinants of consumer attraction such as pleasant pungent taste and hotness can vary with
agronomical practice, crop region, and drying conditions in addition to others. The current study
focused on chemical compositions and antioxidant activities of the three Capsicum annuum
varieties of Omo Nada district, Jimma zone, Ethiopia. The samples of three varieties of C. annuum
(Gojeb, Kolesha, and Marako) were collected purposively from the Omo Nada district of Jimma
Zone. GC-MS analysis of the n-hexane extracts of C. annuum fruits revealed the presence of 43,
47, and 42 compounds in the Marako, Kolesha, and Gojeb varieties, respectively. Meanwhile, the
n-hexane extract of the Gojeb cultivar showed the highest 2,2-diphenyl-1-picrylhydrazyl (DPPH)
radical scavenging activity which would have been due to the highest percentage of capsaicin,
dihydrocapsaicin, and vitamin E. Moreover, the total phenolic content (TPC), total flavonoid
contents (TFC), and DPPH radical scavenging activity were investigated by UV-Vis spectroscopy
using methanol and chloroform extracts which were independently obtained by maceration. The
TPC of methanol extracts was 15.18 ± 0.03, 18.50 ± 0.42, and 22.98 ± 0.08 mgGAE/g for Kolesha,
Marako, and Gojeb cultivars, respectively. In the same order, TPC was 12.03 ± 0.03, 13.85 ± 0.74,
and 14.63 ± 0.09 mgGAE/g for chloroform extracts. The TFC was also the highest in methanol
extracts; 5.5 ± 0.052, 5.73 ± 0.02, and 7.67 ± 0.07 mgQE/g for Kolesha, Marako, and Gojeb
varieties, respectively. Chloroform extracts exhibit lower TFC, which varied from 3.72 ± 0.07 to,
4.73 ± 0.32 mgQE/g. Regarding the antioxidant activity, the IC50 values for the DPPH radical
scavenging were 0.92 ± 0.01, 1.36 ± 0.06 mg/mL, 0.39 ± 0.004, 0.82 ± 0.01 mg/mL, and 1.40 ±
0.02, 1.52 ± 0.03 mg/mL for methanol and chloroform extracts of Marako, Gojeb, and Kolesha,
respectively. The result of the current study showed three varieties of peppers could be considered
as a source of antioxidant bioactive compounds.
