Quantification of Carotenoids in Foods Using Relative Response Factors by HPLC with a Photodiode Array Detector

Carotenoids are naturally occurring plant pigments and play important roles in human health. Low stability and availability of carotenoid standards remain key challenges to the accurate quantification of carotenoids in foods. In this study, a quantification method using relative response factors (RRFs) in HPLC-PDA was developed and validated for the quantitation of carotenoids in plant foods. Authentic standards of 10 carotenoids commonly found in plant-based foods were obtained commercially. The RRF of each individual standard was generated against β-carotene. Method validation was conducted to assess specificity, limit of detection, limit of quantification, linearity and working range, precision, and accuracy. In addition, quantifications of carotenoids in selected food samples by HPLC using RRF and individual standards were conducted and compared. Method validation results suggested that the method is reliable and reproducible. Quantifications of carotenoids in five different leafy green vegetables using RRFs yielded results comparable to and consistent with those using individual standards. The quantification method using RRF provides an accurate, consistent, and cost-effective approach for quantifying major carotenoids in plant foods.