Validation of the High-Performance Liquid Chromatography Method for Determining Quercitrin in Capsicum annuum L. Cultivar Dangjo

Capsicum annuum L. cultivar Dangjo (DJ), developed as a novel crop, possesses potential health benefits, such as reducing blood glucose levels. DJ contains flavonoid glycosides, bioactive compounds that have been found in various plants and have promising pharmacological effects. A representative flavonol glycoside is quercitrin, a standard compound. Notwithstanding, its adoption by the food industry, it is necessary to standardize the quantification of quercitrin in DJ. Thus, an analytical method needs to be developed and validated to quantify quercitrin accurately. In this study, we established a high-performance liquid chromatography (HPLC) method for quantifying quercitrin in DJ extracts (DJEs); then, we validated the method, to ensure its accuracy and reliability. Our results demonstrated that the HPLC method effectively detecteds quercitrin in DJE samples, consistently reporting retention times and peak spectra similar to those in the standard solutions. The linearity assessment revealed a linear response within the concentration range of 2.5 to 15.0 μg/mL, which was supported by strong correlation coefficients (R²>0.9997). Accuracy assessment via recovery studies produced satisfactory results (89.02%－99.30%), with a relative standard deviation (RSD) within acceptable limits (0.50%－5.95%). Precision analysis confirmed the repeatability and reproducibility of the method, with RSD values within the Association of Official Agricultural Chemists (AOAC) standard criteria (≤8%). Overall, our study provides a validated HPLC method for quercitrin quantification in DJEs, facilitating its standardization and ensuring the accuracy of the analysis. This method is potentially valuable for quality control and further research on the health-promoting properties of DJ.