Phenolic profile and antioxidant capacity of landraces, old and modern Tunisian durum wheat

Abstract

In the last decades, the consumption of whole wheat has increased because consumers' awareness has increased toward healthy food. However, breeders' focus was always attributed to the major components of wheat, but less attention was paid to micronutrients. The aim of this study was to provide new insights on the influence of breeding on total polyphenol content (TPC), phenolic profile, and total antioxidant capacity (TAC) using a set of Tunisian durum wheat landraces, old and modern varieties. Ultra-liquid chromatography multi-stage mass spectrometry (UHPLC-MSn) allowed the identification of eight phenolic acids, which were found in the bound form, while only p-coumaric acid was found in the free form. A significant genotype effect on the TPC (bound, free and total), TAC, and phenolic acid profile was observed. Regarding breeding effect, TPC concentrations were in the order modern>landraces>old. Principal component analysis (PCA) confirmed that the phenolic profile of the studied varieties was mainly conditioned by their genotypic characteristics, and no trend was observed as a function of breeding history. Likewise, clustering analysis highlighted an important genetic diversity, suggesting that the modern variety Om Rabia'' possesses the most interesting phenolic profile. These findings might be useful to breed genetically different and phenolic-rich new varieties.