Comparative proteomic analysis of green malts between barley (Hordeum vulgare) cultivars

• A comparative proteomic study of green malts from two barley cultivars was performed.
• Differentiating proteins were detected by fluorescent difference gel electrophoresis.
• These proteins were identified by tandem MS and related to malt quality differences.
• One third of these cultivar-differential proteins were not found in malts.

The variety of metabolic proteins theoretically reaches a peak at the end of germination in large-scale malting. In the present study, comparative proteomics based on two-dimensional fluorescent difference gel electrophoresis (2D-DIGE) was employed to quantitatively analyse the low-salt soluble proteins in green malts from cultivars of Dan’er and Metcalfe. Fifty-nine metabolic proteins with significant differences between cultivars were successfully identified using MALDI-TOF/TOF. The roles of differential proteins in malt quality discrimination were elucidated according to their functions. Among them, 18 proteins exhibited differences in the green malts but not in the malts between the two cultivars. They could be considered as supplementary contributors to the quality defects of Dan’er malt, and new markers for malt quality improvement.