Polyphenolic Composition and Antioxidant Activities of Twelve Capsicum annuum Cultivars Revealed by RP-HPLC and Chemometric Analysis.

This study aimed to comparatively characterize the polyphenolic composition and antioxidant activities of Capsicum annuum (C. annuum) cultivars. Twelve C. annuum cultivars representing red, yellow, and green groups were collected, extracted using methanol, and analyzed by reversed-phase high-performance liquid chromatography (RP-HPLC) for the identification and quantification of phenolic acids and flavonoids. Multivariate chemometric analysis was performed using principal component analysis (PCA), hierarchical cluster analysis (HCA), and heat map analysis. Antioxidant potential was assessed by total phenolic contents (TPC), total flavonoid contents (TFC), 2,2'-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity, and the β-carotene-linoleic acid bleaching assay. The extract yields of the twelve C. annuum cultivars ranged from 20.21-39.41 g/100 g of dry material. Thirteen phenolic acids, six flavonoids, and three other polyphenols were identified. Gallic acid was the most dominant phenolic acid, ranging from 54.72 mg/kg in Libra to 1058.72 mg/kg in SP-53, whereas catechin was the major flavonoid, ranging from 83.47 mg/kg in AS-102 to 691.79 mg/kg in Rani. Multivariate analysis revealed cultivar-dependent heterogeneity in phytochemical composition and highlighted the usefulness of chemometric approaches for resolving inter-cultivar phytochemical diversity. TPC ranged from 30.51 to 60.81 mg gallic acid equivalent (GAE)/g dry plant material, whereas TFC ranged from 9.10 to 30.91 mg catechin equivalent (CE)/g dry plant material. Antioxidant activities also differed significantly among cultivars. Collectively, these findings demonstrate cultivar-dependent variation and support the potential of C. annuum cultivars as promising candidates for nutraceutical and functional food applications.