Exploring biochemical variability in (Capsicum annuum L.) germplasm through HPLC analysis of capsaicinoids and antioxidants
摘要
An optimized high-performance liquid chromatography (HPLC) method was applied to analyze 133 Capsicum accessions, focusing on capsaicinoids and antioxidant compounds, offering enhanced accuracy and efficiency in the analysis. The study revealed considerable variation in the content of capsaicin, dihydrocapsaicin, ascorbic acid, and β-carotene across the pepper germplasm. Hot pepper accessions demonstrated a wide range of capsaicinoid content, whereas sweet pepper accessions lacked these compounds. The highest capsaicin and dihydrocapsaicin levels, 924.27 µg g⁻1 dry weight (DW) and 612.05 µg g⁻1 DW, respectively, were recorded in accession 36658. Accession 36111 had the highest (3176.5 µg g−1 DW) ascorbic acid, while accession 36572 exhibited the maximum (1318.07 µg g−1 DW) β-carotene content. The correlation analysis showed a strong and significant positive relation between dihydrocapsaicin and capsaicin (r = 0.90), indicating a close relationship between these two compounds. Hierarchical cluster analysis (HCA) was performed for organizing and managing accessions; clusters were partitioned at a similarity coefficient of 390, resulting in seven distinctive clusters. Principal component analysis (PCA) revealed that the first two components explained 90.76% of the total variance, PC1 explained 48.80% and PC2 explained 41.96% of the variation among the accessions. These findings are crucial for selecting genetically diverse accessions with high nutritional value, which could be used in future breeding initiatives to enhance the nutritional quality of Capsicum species.