Distributions of nutrients and avenanthramides within oat grain and effects on pearled kernel composition

•Nutrients and avenanthramides are unevenly distributed within oat kernels.•Avenanthramides were most concentrated in outer layers of oat grains.•Avenanthramide contents and distribution within grains vary with oat varieties.•Pearled oats have lower contents of avenanthramides, protein, oil, and ash.•Pearled oats, however, contain higher concentrations of beta-glucan and starch.