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 Mw 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.
Keywords: barley genotype; barley growth conditions; barley yield; malting; β-glucan; β-glucan molecular properties.