This study assessed the phytochemical profiles of methanolic extracts in a large oat collection grouped by hulls of different colors and geographical origins. The assessment was performed on whole oats without separating the groats from the hull. The methanolic extracts effectively discriminated the wide phytochemical composition variability among oats. White oats exhibited the highest concentration of avenanthramides, while yellow and beige oats had the lowest. The highest total phenolic acid content (TPAC) was found in brown oats, with syringic, vanillic, caffeic, and ferulic acids, as well as vanillin, being the most abundant. In naked oat, caffeic acid was the most abundant. Antioxidant Activity (AA) measured by ABTS and DPPH was the highest in the white and brown groups, while the lowest was in the naked group. The PCA indicated that the strong AA in white oat genotypes can be attributed to the presence of avenanthramides and caffeic acid. In contrast, for the brown group, it is due to TPAC and ferulic acid. Moreover, the separation of oat groups by geographic origins was identified. The antioxidant molecules involved in AA are well associated with the hull’s color. The soluble wholemeal extracts proved to be a useful tool for discriminating antioxidant profiles in this large oat collection.
Menga et al. (Sat,) studied this question.