Genotype and Environment Shape the Free and Bound Phenolics and Lipid Content in Oat (Avena sativa L.) Grains

Oat grains contain antioxidants, such as phenolics, with beneficial health properties. This study aimed to assess the effects of genetic and environmental factors on the content of free and bound phenolic compounds, their antioxidant capacities, and lipid levels in naked and hulled oat varieties grown in various Polish locations over two crop years. The genotype explained the largest variance in all measured parameters, although environmental factors also influenced these traits. The year of cultivation primarily affected free phenolics and their antioxidant activity, while growth location influenced bound compounds and their capacities. Significant correlations were observed between phenolic levels and antioxidant activity within each fraction. Hulled oat cultivars exhibited higher bound phenolic contents and lower lipid levels compared to naked varieties. Although the study highlighted the differential responses of phenolic fractions to external factors, further research is necessary to elucidate the mechanisms that regulate phenolic biosynthesis in oats. Such insights could facilitate the development of oat varieties optimized for specific growing conditions to maximize the accumulation of beneficial phenolic antioxidants.