Tocol content in oat varieties grown under different environmental conditions and farming systems

Abstract

The effect of variety and environmental factors on the tocol content and composition in oat grain determined by liquid chromatography with fluorescence detection was investigated. Basic grain parameters – such as yield, TKW (thousand kernel weight), and fat content – and their relation to the tocol content were also monitored. Four varieties of hulled oats (Kertag, Korok, Seldon, Raven) and one of naked oats (Patrik) were grown over two years, at two different localities, under conventional and organic farming systems. The total tocol content ranged from 68.4 to 163 μg/g DW and consisted of only α- and β-forms of tocols, with α-tocotrienol predominating (68.2%), followed by α-tocopherol (26.4%). The year was the largest contributor to the overall variability, with significantly higher tocol content in 2019 (143 μg/g DW) compared to 2020 (94.9 μg/g DW). The effect of the variety and farming system was significant only for the minor β-forms of tocols, while locality represented a statistically insignificant factor. Tocol content was strongly negatively correlated with TKW (−0.75) and moderately negatively correlated with grain yield (−0.44). Conversely, a moderate positive correlation (0.44) was found between the tocol content and grain fat content, with higher values for α-forms of tocols.