Influence of genotype, environment and year on antioxidants in durum wheat (Triticum turgidum L. var. durum)

Whole grains are well known to contain high amount of dietary fibre, various minerals and vitamins and also several bioactive compounds, most of which with antioxidant properties contributing to their health-promoting effects. These compounds include different chemical structures like tocopherols, alkylresorcinols, phytosterols, carotenoids and phenolic acids (PAs) with different chemical structures. Several studies have shown a significant impact of genotype and environment on the occurrence of antioxidants in cereals. Nevertheless, few studies focused their evaluations on durum wheat (Triticum turgidum L. var. durum) which is a crop of primary importance in the Mediterranean area and most of all in Italy, where it is mainly used for pasta production. The aim of this study was to investigate the effects of genetic and environmental factors on the total antioxidant activity (TAC) and on the occurrence of some antioxidant compounds such as yellow coloured pigments (YCP), phenolic acids (PAs) and total phenolics (TPC), both occurring in soluble free, soluble conjugated and insoluble bound forms. In this work, three durum wheat genotypes grown in three Italian cultivation areas over three consecutive crop years were considered. In order to better investigate the effect of genotype, the investigation was extended to seven additional genotypes in one of the selected growing areas, across the same three consecutive crop years. Results show that crop year, genotype, growing area and their interactions significantly affected the variables under study. The content of PAs and TPC were primarily affected by environment and secondly by the genotype, to a different extent for the 3 forms. The TAC level as well as the YCP content was indeed mostly influenced by genetic factors. These findings might be useful for selecting durum wheat genotypes naturally rich in antioxidant compounds, also in relation with the growing area, as well as for the development of cereal-based foods with an improved potential nutritional and health value.