5- n-Alkylresorcinol Profiles in Different Cultivars of Einkorn, Emmer, Spelt, Common Wheat, and Tritordeum

5-n-Alkylresorcinols (AR) are bioactive compounds found in the edible parts of many cereals. Here, saturated and unsaturated homologues, including the oxidized forms 5-(2′-oxo) AR and their plant metabolites, were profiled by ultrahigh-performance liquid chromatography-ion mobility separation-high-resolution mass spectrometry in 18 cultivars of einkorn, emmer, spelt, common wheat, and tritordeum, cultivated in two consecutive years under uniform agronomic conditions. The average content of AR ranged between 672.5 ± 129.8 and 1408.9 ± 528.0 mg/kg, exceeding 2380 mg/kg in some samples and highlighting a superior content in tritordeum and in modern cultivars with respect to old wheat genotypes. By evaluating the effect of environmental and agronomic factors on the different variables, the harvest year resulted to be always significant, while location and variety influenced AR abundance only for some homologues. Furthermore, the spatial distribution of AR was investigated by mass spectrometry imaging using transversal cross sections of wheat kernels. Our results show that AR homologues are mainly localized in the testa and in the outer pericarp of wheat kernels.