Characteristics of the Content and Variability of Dietary Fiber Components and Alkylresorcinols of Rye Grain (Secale cereale L.)

Rye (Secale cereale L.) is one of the most important cereals cultivated in Central and Eastern Europe, valued for its high resistance to environmental stress and high levels of bioactive compounds, such as dietary fiber (DF) and alkylresorcinols (ARR). The aim of the study was to evaluate the content and variability of DF fractions and ARR in rye grain of hybrid and population cultivars. The research was conducted on grain from four rye cultivars cultivated in five locations over three consecutive growing seasons. The content of DF, its fractions, and ARR, was determined using enzymatic–gravimetric and colorimetric methods. The results showed significant variability in all analyzed traits, with environmental conditions and G×E interaction having the greatest impact on their content. Hybrid cultivars were characterized by a higher and more stable content of bioactive compounds. Notable average values for hybrids vs. populations included DF: 153.9 vs. 151.7 g kg⁻¹, NSP: 129.4 vs. 127.7 g kg⁻¹, lignin: 24.5 vs. 24.0 g kg⁻¹, β-glucan: 21.7 vs. 20.6 g kg⁻¹, and ARR: 1015 vs. 987 g kg⁻¹. The KWS Serafino cultivar characterized by the highest and most stable content of bioactive compounds. Selecting genotypes with stable chemical profiles regardless of environmental conditions is crucial for developing nutritionally valuable rye-based products.