Determination of carotenoids in Chinese vegetables

Seven leafy Chinese vegetables, gau choi (Allium tuberosum), een choi (Amaranthus tricolor), baak choi (Brassica chinensis), choi sum (Brassica parachinensis), wong baak (Brassica pekinensis), ong choi (Ipomoea aquatica) and sai yeung choi (Rorippa nasturtium aquaticum) were analysed for carotenoids by reversed-phase HPLC and gradient elution. Sixteen carotenoids were identified as being present at levels of more than 2% of total carotenoids. For all leafy vegetables, lutein was the major carotenoid with β-carotene present at substantial levels. Violaxanthin, neoxanthin, antheraxanthin and mutatoxanthin were also important contributors in specific produce.