Effect of Growth Conditions and Genotype on Barley Yield and β‑Glucan Content of Kernels and Malt

This study was conducted to evaluate the effect of growth conditions and genotype on the barley yield and β-glucan content of grain and malt. Total and water-extractable (W-E) β-glucans and their molecular and structural properties were analyzed in nine 2-row barley varieties and corresponding malts. The total β-glucan content of barley is not influenced by year or by the cultivar, while the grain yield and W-E β-glucan content are significantly influenced by the year. Barley W-E β-glucans have a molecular weight between 1.0 × 105 and 4.0 × 105 Da and a random coil conformation. β-Glucan levels in malt are significantly lower than in barley, and neither the total nor the W-E β-glucans are influenced by environmental factors or genetic aspects. W-E β-glucans are mainly composed of fractions with M w values below 1.0 × 105 Da. In conclusion, the molecular characterization of β-glucans could represent a powerful tool to understand their role in the brewing process.