PLS calibration to resolve overlapping peaks of Lutein and Zeaxanthin in vegetable samples by LC

Abstract

The chromatographic method in combination with a Partial Least Squares (type PLS-1) chemometric tool was developed to analyse simultaneously the carotenoid compounds, lutein and zeaxanthin. Both analytes appear together in the same chromatographic peak. Different calibration matrices were done using the absorbance spectra, obtained in the peak apex. The method was successfully applied to plant material such as cabbage, broccoli, red pepper, yellow pepper, and green pepper. The higher content of lutein was found in the green leafy vegetables such as broccoli and cabbage. On the other hand, zeaxanthin was only found in pepper, with the highest concentration having been found in red pepper.