| dc.description.abstract | Fruits and vegetables represent an essential source of phytonutrients, including antioxidants and other health-promoting compounds. Peppers (Capsicum spp.) are rich sources of many phytonutrients and accurate, rapid quantitation of the capsaicinoid and capsinoid compounds produced by peppers is essential to assess quality. Here, we developed a rapid ultra-high performance liquid chromatography method for the simultaneous separation of five major capsaicinoids and three major capsinoids from peppers. Optimal chromatographic separation was achieved using a phenyl-hexyl stationary phase with a mobile phase of acidified water and methanol with a flow rate of 0.5 ml/min at a column temperature of 55 °C over 5 minutes. The method was validated by testing linearity, precision, robustness, and limits of detection and quantification. The developed method was successfully employed to profile capsaicinoids and capsinoids from different pepper cultivars. Out of the 10 pepper cultivars analysed, all three major capsinoids were detected in two cultivars. To the best of our knowledge, this is the first report of successful separation of nordihydrocapsiate from capsiate and quantification of nordihydrocapsiate. Even with widely reported health benefits of these phytonutrients, limited studies have compared the composition of different types of peppers and their properties that may improve health. In this study, we measured the phytochemical composition of different pepper types, such as habanero, jalapeño, serrano, and ancho peppers. Significant differences were observed in the concentrations of phytonutrients in the different pepper types. In general, habanero-type hybrids had significantly higher vitamin C content as compared with the jalapeño, and serrano-type hybrids. Seven major flavonoids were identified using ultra high-performance liquid chromatography-mass spectrometry. Habanero and ancho types had the highest flavonoid concentrations among different pepper hybrids. The ancho-type hybrid ‘TAM EH-227’ showed the highest total phenolics content (1338.13 µg g-1), the habanero-type ‘TAM EH-45’ showed the highest DPPH free radical scavenging activity (850.82 µg g-1), and the habanero type ‘TAM MH’ (1026.32 µg g-1) had the highest ABTS free radical scavenging activity. Taken together, our results show that the phytonutrient contents in pepper hybrids vary substantially; this information lays a foundation for breeding peppers with high concentrations of health-promoting phytonutrients. | |
