Barley (Hordeum vulgare) has the potential to offer considerable human nutritional benefits, especially as supplement to wheat-based breads. Under current commercial baking conditions it is not possible to introduce more that 20% barley flour to the wheat bread without negative impact on the physical chemical properties of the bread products due to the poor baking properties of barley flour. As a consequence, the nutritional advantages of barley are not fully exploited. The inferior leavening and baking properties of barley can, in part, be attributed to the physical properties of the storage proteins. Changing the storage protein composition can lessen this problem. Our working hypothesis was that exploiting the substantial genetic variation within the gene pool for storage proteins could enable improving the baking qualities of barley flour. We characterised forty-nine barley cultivars for variations in storage protein and AA composition. These cultivars were selected based on their higher protein contents (11.8–17.6%). The results obtained indicated that substantial variation not only in the distribution of the hordein polypeptides but also in the relative proportions of the storage proteins affecting the AA compositions as well. Studies based on small scaled baking trials and protein pattern analysis by SDS-PAGE on the high protein barley cultivars suggested differences in baking quality and a correlation between baking quality and the high molecular weight (HMW)-storage proteins. Mass spectrometry (Q-TOF) proved the identity of the HMW proteins and sequencing the digested peptides also revealed possible post translational modifications of the identified HMW hordeins. Our results strongly indicate that the variations in the relative proportions of the storage proteins of barley affect both the amino acid compositions and baking quality.
24th Njf Congress, 2nd Nordic Feed Science Conference. Book of Abstracts, 2011, p. 79-85