Total Phenolic and Flavonoid Content, Lipophilic Components, and Antioxidant Activities of Capsicum annuum Varieties Grown in Omo Nada, Jimma, Ethiopia

Objective This study aimed to determine total phenolic content (TPC), total flavonoid content (TFC), lipophilic components, and antioxidant activities of Capsicum annuum L. varieties grown in Omo Nada, Jimma, Ethiopia.Methods Fresh, ripe fruits from three commonly cultivated varieties of C. annuum - Mareko Fana, Kolesha, and Gojeb - were investigated. TPC and TFC were measured using Folin-Ciocalteu and aluminum chloride colorimetry methods in methanol and chloroform extracts, expressed as mg gallic acid equivalents (mg GAE/g) and mg quercetin equivalents (mg QE/g), respectively. Lipophilic components were identified in n-hexane extracts using gas chromatography-mass spectrometry (GC-MS). Antioxidant activities were assessed using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging assay.Results Methanol extracts had the highest TPC and TFC across all varieties, with Gojeb exhibiting the highest values (TPC: 22.98 +/- 0.08 mg GAE/g; TFC: 7.67 +/- 0.07 mg QE/g). GC-MS analysis identified 80 distinct compounds in n-hexane extracts, with m-xylene and p-xylene (6.68-16.82%), capsaicin (4.22-11.25%), dihydrocapsaicin (2.12-8.24%), vitamin E (5.32-14.72%) and (24R)-stigmast-5 -en-3beta-ol (2.19-6.20%) being among the major components across all varieties. The DPPH assay revealed that methanol extracts of Gojeb had the strongest antioxidant activity with EC50 values of 0.40 +/- 0.04 mg/mL. Moreover, the EC50 showed strong negative correlation with TPC ((r = -0.87).Conclusion The methanol extracts of C. annuum varieties, especially Gojeb, exhibited high TPC, TFC, and antioxidant activity, highlighting its importance as potential sources of natural antioxidants in food or pharmaceutical industries. Despite their lower antioxidant activities, the n-hexane extracts contain valuable health-promoting compounds. Further research, involving chemical isolation and additional bioanalysis could give more insight about the health benefits of the C. annuum varieties investigated.