Carotenoid and chlorophyll pigments in sweet basil grown in the field and greenhouse

Abstract

Sweet basil (Ocimum basilicum L.) is a popular culinary herbal crop grown for fresh or dry leaf, essential oil, and seed markets. Recently, basil was shown to rank highest among spices and herbal crops for xanthophyll carotenoids, which are associated with decreased risks of cancer and age-related eye diseases. The research goal for the current study was to characterize the concentrations of nutritionally important carotenoid pigments in popular varieties of basil. Eight cultivars of sweet basil ('Genovese', 'Italian Large Leaf, 'Nufar', 'Red Rubin', Osmin Purple', 'Spicy Bush', 'Cinnamon', and 'Sweet Thai') were grown in both field and greenhouse environments and evaluated for plant pigments using HPLC methodology. Environmental and cultivar differences were observed for all of the pigments analyzed. 'Sweet Thai' accumulated the highest concentrations of lutein, zeaxanthin, and β-carotene carotenoids in the field, while 'Osmin Purple' accumulated the highest carotenoid concentrations in the greenhouse. Comparing the two environments, cultivar levels for carotenoid and chlorophyll pigments were higher in the field environment when expressed on both a fresh and dry weight basis. Exceptions were found only for the purple leaf basils ('Osmin Purple' and 'Red Rubin'). Positive correlations existed between carotenoid and chlorophyll pigments in both environments. This study demonstrates sweet basil accumulates high levels of nutritionally important carotenoids in both field and greenhouse environments.