Influence of agricultural management on phytochemicals of colored corn genotypes (Zea mays L.). Part 1: Nitrogen fertilization

In this study, the influence of nitrogen (N) fertilization (170 vs 300 kg N/ha) on the content of bioactive compounds of whole-meal flour of 10 different colored corn genotypes was investigated. Considerable differences in antioxidant capacity and phytochemical concentrations were observed among genotypes. Higher N fertilization rates significantly (P<0.05) increased the content of both total cell-wall bound phenolics and xanthophylls (lutein and zeaxanthin). Nevertheless, the main phenolic acids (ferulic, p-coumaric and sinapic acids), as well as the antioxidant capacity and the content of β-cryptoxanthin, β-carotene and total anthocyanins did not show significant differences as far as the N fertilization rate is concerned. For corn cultivation, the application of high N fertilization rates, generally carried out in order to obtain higher grain yields, could positively influence the content of some bioactives particularly in years characterized by high rainfall levels responsible of a N leaching from the soil.