Liquid chromatographic method for the determination of chlorophylls, carotenoids, and their derivatives in fresh and processed vegetables

摘要

A high-performance liquid chromatographic method has been developed to quantify major chlorophylls and carotenoids in some raw and processed vegetables. Vegetable samples were simultaneously homogenized and extracted with methanol in a homogenizer in two steps. A sample to solvent ratio of 1:10 (w/v) was sufficient for a complete extraction of pigments from pea. The extraction yields were determined to be 79.1% and 20.9% for the first and the second extraction steps, respectively. A MikroPak C8 reversed-phase column was used for the separation of chlorophylls and carotenoids in an elution time of 20 min using gradient mixture of methanol: water at a flow rate of 0.75 mL/min. A good separation of chlorophyll a (Chl a) and chlorophyll b (Chl b), and of their major derivatives, was achieved. The method has also been shown to be applicable for the separation of yellow (< alpha >- and < beta >-carotenes) and orange (xanthophylls) carotenoids in some vegetables. The method was shown to be useful to quantify Chl a and Chl b, and of their Mg-free derivatives of Pheo a and Pheo b, in some fresh and processed peas, as well as to quantify < beta >-carotene in carrots.