(Poly)phenols, Carotenoids, and Tocochromanols in Corn (Zea mays L.) Kernels As Affected by Phosphate Fertilization and Sowing Time.

Corn (Zea mays L.) growth and development is often limited by the availability of phosphate. We thus hypothesized that phosphate fertilization may increase the contents of (poly)phenols, carotenoids, and tocochromanols (vitamin E) in corn grains. Corn plants cultivated on a soil fertilized with 44 kg phosphorus/ha were compared to plants grown on soil with low plant-available phosphate (1.6 mg CAL-P/100 g of soil), each sown early (April) and late (May) in a randomized field experiment. HPLC-DAD-(HR)-ESI-MSn revealed 19 soluble and 10 insoluble (poly)phenols, comprising phenolic acids, phenolic amines, diferulic, and triferulic acids in corn grains. Contents of individual (poly)phenols, carotenoids, and tocochromanols in whole grains were significantly (p < 0.05) increased by sowing time, but not by phosphate fertilization. In conclusion, low phosphate availability did not impair the biosynthesis of (poly)phenols, carotenoids, and tocochromanols in corn grains.