Characterization of Protein Profiles and Their Role in Malting Quality of Commercial Barley Genotypes (Hordeum vulgare)

Abstract

n Argentina, the cultivation of malting barley (Hordeum vulgare L.) has expanded significantly, driven by the increasing demand of the brewing industry for barley malt. However, the predominance of the Andreia cultivar has reduced genetic diversity, increasing its vulnerability to environmental fluctuations and limiting the selection of new genotypes with desirable malting traits. Based on the hypothesis that significant biochemical variability exists among the commercial genotypes currently available in Argentina, this study provides the first comprehensive assessment integrating germination performance, protein content, hordein composition, and amylolytic enzyme activity in these genotypes. Twelve malting barley genotypes were evaluated under uniform growing conditions, and biochemical analyses were conducted on micromalted grains. Gel Electrophoresis revealed polymorphisms mainly in B- and C-hordeins, supporting genetic differentiation among cultivars. The total protein content ranged from 9.5% to 13.2%, whereas soluble hordeins varied from 5.8% to 12.9% of the total protein. α-Amylase activity values ≥ 150 U/g were observed in all cultivars evaluated, except for Sinfonía. However, amylolytic activity, which is related to diastatic power, was higher in genotypes such as Andreia, Alhue, Aliciana, and Jennifer. Correlations between protein content, enzyme activity, and hordein profiles indicated genotype-dependent biochemical patterns in the barley grains. Overall, this study highlights the existence of relevant biochemical diversity among Argentine commercial genotypes, providing valuable information for breeding programs aimed at improving malting quality and promoting productive diversification in the national barley industry.