Deciphering the potential of diverse barley genotypes for improving the malt quality

Abstract

The quality of barley grains and malt significantly influences the fermentation process and the ultimate quality of beer. However, the diverse range of desired quality requirements complicates the selection of suitable malting barley varieties. Achieving a combination of all desirable traits within a single genotype poses a significant challenge. This study aimed to identify the most promising malting genotypes by evaluating the malting potential of 29 barley genotypes, considering various grain (plumpness, hectolitre weight, grain protein, starch and β-glucan content) and malt quality (diastatic power, filtration rate, hot water extract, kolbach index and green malt β-glucanase activity and β-glucan content) traits. Significant genotypic variations were observed for individual grain and malt traits. Low malt β-glucanase activity led to high β-glucan content and low diastatic power, affecting the profile of fermentable sugars in the wort. Therefore, β-glucanase activity and β-glucan content were identified as potential additional selection criteria for producing high-quality malt. A weighted scoring system based on eight quality traits identified ten barley genotypes that outperformed the check varieties. Among them, three genotypes (BL1523 > PL807 > BL1748) exhibited exceptionally higher scores than the check varieties. Furthermore, wort sugar profiling confirmed the potential of these genotypes as valuable contributors to future barley improvement programs aimed at enhancing malt quality.