Non-targeted metabolomic analysis of hot pepper (Capsicum annuum "CM334") was performed at six development stages [16, 25, 36, 38, 43, and 48 days post-anthesis (DPA)] to analyze biochemical changes. Distinct distribution patterns were observed in the changes of metabolites, gene expressions, and antioxidant activities by early (16-25 DPA), breaker (36-38 DPA), and later (43-48 DPA) stages. In the early stages, glycosides of luteolin, apigenin, and quercetin, shikimic acid, γ-aminobutyric acid (GABA), and putrescine were highly distributed but gradually decreased over the breaker stage. At later stages, leucine, isoleucine, proline, phenylalanine, capsaicin, dihydrocapsaicin, and kaempferol glycosides were significantly increased. Pathway analysis revealed metabolite-gene interactions in the biosynthesis of amino acids, capsaicinoids, fatty acid chains, and flavonoids. The changes in antioxidant activity were highly reflective of alterations in metabolites. The present study could provide useful information about nutrient content at each stage of pepper cultivation.
Keywords: antioxidant activity; biosynthetic pathway; fruit development stage; hot pepper; metabolomics.