Genetic variation of carotenoids, vitamin E and phenolic compounds in Provitamin A biofortified maize

BACKGROUND Biofortified maize is not only a good vehicle for provitamin A carotenoids for vitamin A deficient populations in developing countries but also a source of vitamin E, tocochromanols and phenolic compounds, which have antioxidant properties. Using high‐performance liquid chromatography and a total antioxidant performance assay, the present study analyzed the antioxidant variation and antioxidant activity of 36 provitamin A improved maize hybrids and one common yellow maize hybrid. RESULTS The ranges of major carotenoids in provitamin A carotenoids biofortified maize were zeaxanthin [1.2–13.2 µg g −1 dry weight ( DW )], β‐cryptoxanthin (1.3–8.8 µg g −1 DW ) and β‐carotene (1.3–8.0 µg g −1 DW ). The ranges of vitamin E compounds identified in provitamin A carotenoids biofortified maize were α‐tocopherol (3.4–34.3 µg g −1 DW ), γ‐tocopherol (5.9–54.4 µg g −1 DW ), α‐tocotrienol (2.6–19.5 µg g −1 DW ) and γ‐tocotrienol (45.4 µg g −1 DW ). The ranges of phenolic compounds were γ‐oryzanol (0.0–0.8 mg g −1 DW ), ferulic acid (0.4–3.6 mg g −1 DW ) and p ‐coumaric acid (0.1–0.45 mg g −1 DW ). There was significant correlation between α‐tocopherol and cis isomers of β‐carotene ( P  < 0.01). Tocotrienols were correlated with α‐tocopherol and γ‐oryzanol ( P  < 0.01). CONCLUSION Genotype was significant in determining the variation in β‐cryptoxanthin, β‐carotene, α‐tocopherol and γ‐tocopherol contents ( P  < 0.01). A genotype × environment interaction was observed for γ‐tocopherol content ( P  < 0.01). © 2016 Society of Chemical Industry