The representation of individual barley grain proteins plays a key role in the quality of malt as well as beer. In addition, specific proteins can be used for the discrimination of barley cultivars. Thus, the determination of protein pattern is crucial in many biochemical studies. Several European barley cultivars were examined in this work. Spring barley malting varieties Tolar, Malz, Bojos, and Blaník are significant in the malting and brewing industry in countries of the Central and Eastern Europe, and they were recommended as varieties suitable for the production of Czech beer with protected geographical indication. The protein contents of these cultivars were compared with those of Jersey variety (intended for malt export) and AF Lucius (a nonmalting hull-less cultivar). Water-, salt-, and alcohol-soluble proteins were extracted from each cultivar of barley. Protein classes obtained according to their solubility were determined electrophoretically and in the case of water-soluble proteins also chromatographically with MALDI-TOF/TOF MS. In particular, quantitative differences in albumin composition were found among the investigated barley varieties. The grains of Blaník and Jersey were the most different from the others. They had the highest proportional representation of nonspecific lipid transfer protein 1, α-amylase/subtilisin inhibitor, and β-amylase. Our data also show that there are greater differences in the malt profiles of the studied varieties. The proportional representation of ns-LTP1, α-amylase/subtilisin inhibitor, and β-amylase is the lowest in case of Jersey, Tolar, and AF Lucius malt varieties. On the other hand, protein Z seems to have an opposite trend. Keywords: Barley, Gel electrophoresis, MALDI-TOF/TOF MS, Protein profile, RP liquid chromatography, Variety
Supplementary Fig. S1 shows proportional representation of selected proteins found in individual barley varieties of barley grain and malt.
