Influence of Agronomic Practices on the Antioxidant Compounds of Pigmented Wheat (Triticum aestivum spp. aestivum L.) and Tritordeum (× Tritordeum martinii A. Pujadas, nothosp. nov.) Genotypes.

Twelve pigmented wheat genotypes, one tritordeum, and one common wheat were grown in three field experiments under varying nitrogen (N) fertilization rates to investigate the contributions of genotype, environment, and fertilization on the levels of phenolic acids, anthocyanins, carotenoids and antioxidant capacity of the grains. Soluble phenolic acids increased significantly (+16%) in the environment with high soil N content, while bound phenolic acids and anthocyanins decreased (-16 and -57%). N fertilization affected the agronomic and qualitative traits but had limited effects on some bioactive compounds (bound phenolic acids and anthocyanins). The greatest differences appeared among the color groups and within the same color types, with the black group showing the most anthocyanins and phenolic acids (34.4 and 1207 mg·kg-1) and the highest antioxidant capacity. Some of the cultivars could be promising for the development of innovative supply chains and the production of functional foods, as they showed good yield and quality performances, and good antioxidant features.

Carotenoid content of extruded and puffed products made of colored-grain wheats.

Wheat is a relevant source not only of essential macronutrients but also of many other health-promoting phytochemicals (carotenoids, anthocyanins, tocols, phenolic acids, etc.). Colored-grain wheats were used for extrusion and kernel puffing. The total content of carotenoids (sum of lutein, zeaxanthin, antheraxanthin, α- and ß-carotene, and xanthophyll esters) decreased significantly due to extrusion (to 25.7%) and puffing (to 31.6%), compared to the content in the raw material. Zeaxanthin was shown to be the most stable among all detected carotenoids (30.8 and 48.7% was preserved). The results of the performed analyses have not confirmed greater stability of xanthophyll esters against higher temperatures (decrease to 29.5 and 22.1%). Both technologies induced E-to Z-isomerization of all-E-lutein and puffing also of all-E-zeaxanthin. Higher concentrations of 13-Z- and 9-Z-zeaxanthin were identified in puffed grains (2× and 37× on average). To preserve more carotenoids, it is appropriate to look for a more suitable food processing technology.