Hulled oat (Avena sativa var.Noni) and naked oat (Avena nuda var. Kamil)

This study explores dynamic changes in growth, total phenolic content (TPC), antioxidant activity (AA), and phenolic composition during the germination of hulled and naked oat. The shoots and kernels of the germinated oat were analysed separately. Both TPC and AA increased throughout germination, particularly in the shoots with higher accumulation of the free phenolic fraction. LC–MS analysis of the oat extracts identified avenanthramides, isoschaftoside, vitexin, and phenolic acids as key metabolites. Avenanthramides, a major class of polyphenolic compounds in oats, varied in concentration and distribution between species. Germination notably increased isoschaftoside and vitexin levels by 28- and 5.3-fold, respectively. Differences in phenolic profiles indicate species-specific metabolic responses. To the best of our knowledge, this is the first comparative analysis of secondary metabolites in oat shoots and kernels during germination, providing new insights into growth dynamics and potential health benefits linked to elevated phenolics and antioxidant activity.