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 versus 300 kg of 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 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 to obtain higher grain yields, could positively influence the content of some bioactives particularly in years characterized by high rainfall levels responsible for N leaching from the soil.