Effects of Wheat Cultivar and Nitrogen Application on Storage Protein Composition and Breadmaking Quality

Abstract

Influences of cultivar and nitrogen application on protein concentration and composition, and amount and size‐distribution of different protein components, were investigated in 10 spring wheat cultivars (Triticum aestivum L.) with widely varying gluten strength, grown under four nitrogen fertilizer conditions. The results showed that cultivar differences in gluten strength were determined by storage protein composition, differences in total amount of HMW glutenin subunits, the glutenin‐to‐gliadin ratio, and the relationship between SDS‐soluble and SDS‐insoluble protein polymers. Negative correlations were found between protein parameters related to gluten strength and bread volume. No cultivar stability for gluten strength in relation to differences in nitrogen application was found. Thus, the gluten strength was influenced by the nitrogen application in all the investigated cultivars. Increased nitrogen supply correlated significantly to an increase in all protein components containing gliadins and glutenins, but not to those containing albumins and globulins. The increase in protein components containing gliadins and glutenins correlated significantly with an increase in protein concentration and bread volume.

The influence of Fusarium infection and growing location on the quantitative protein composition of (Part II) naked barley (Hordeum vulgare nudum)

“…This reduction in the albumin and globulin fraction could not be confirmed in the summer barley results as a minor increase in this fraction occurred (Table 6). These results are not supported by N supply studies on wheat as no changes in the albumin and globulin fraction were detected in this cereal [17,32]. The reasons for this reduction in association with N supply in naked barley are unclear, but there may be a suppression of albumin and globulin synthesis at locations with a high N supply in contrast to the induced storage protein synthesis found in naked barley under these conditions (Table 6) [17][18][19].…”

“…4 Quantities of albumins/ globulins, hordein (prolamins) and hordenin (glutelins) protein fractions in naked barley (n = 7) and summer barley (n = 1) at two locations (SH Sattenhausen; RH Reinshof) in grain with different N supplies; significant changes for naked barley are denoted as P values enhanced in comparison to the other three barley protein fractions as it is likely that the promoter motifs are missing, so that the protein synthesis cannot be enhanced. An influence of the amino acid composition or synthesis can be excluded because no characteristic features in amino acid composition were found to be apparent for B-hordenins in comparison to the other types [32].…”

Protein composition in different phases obtained by the ultracentrifugation of dough

“…Proteins from the different phases (11 mg) were extracted and separated on HPLC according to Johansson et al (2001).…”

“…The chromatograms were divided into four sections with a decreasing molecular size range: large polymeric proteins (LPP, peak 1), smaller polymeric proteins (SPP, peak 2), large monomeric proteins (LMP, peak 3) and smaller monomeric proteins (SMP, peak 4) (Johansson et al, 2001;Kuktaite et al, 2000). The percentage of large unextractable polymeric protein in the total large polymeric protein (LUPP) was calculated as [peak 1 area (unextractable) / peak 1 area (total)] × 100.…”

“…In the same way, the percentage of total unextractable polymeric protein in the total polymeric protein (TUPP) was calculated as [peak 1+2 area (unextractable) / peak 1+2 area (total)] × 100. Peak 1+2 (total) refers to the total of peak 1+2 (extractable) and peak 1+2 (unextractable) (Johansson et al, 2001;Kuktaite et al, 2000).…”