The effects of protein characteristics and the proportion of gluten on end-use quality in 13 Korean wheat cultivars for three years were verified in this study.  Year, cultivar, and the interaction between the year and the cultivar influenced protein characteristics, the proportion of gluten except for γ- and ω-gliadin using RP-HPLC (reversed-phase high-performance liquid chromatography), and end-use quality.  Protein characteristics and the proportion of gluten in Korean wheat cultivars were between those of Australian standard white (ASW) and hard wheat (AH).  Korean wheat cultivars exhibited a higher average α+β gliadin proportion than imported wheat, a γ-gliadin proportion similar to that of dark northern spring wheat, and the same ω-gliadin proportion as AH.  They showed a bread-loaf volume intermediate between those of ASW and AH and a texture of cooked noodles similar to that of soft white wheat, but less springiness than imported wheat.  The cookie diameter of Korean wheat cultivars was similar to that of hard red winter wheat.  There was a correlation between bread-loaf volume and protein characteristics, except for the protein content in Korean wheat cultivars.  Springiness and cohesiveness of cooked noodles were not correlated with protein characteristics, while hardness was correlated with the protein content and water absorption of a mixograph.  Cookie diameter was negatively correlated with the sodium dodecyl sulfate (SDS) sedimentation volume and water absorption of a mixograph.  The end-use quality was not correlated with any proportion of gluten composition.  Principal component analysis (PCA) showed that the proportion of gluten was not related to the quality of the bread (both PCs, 81.3%), noodle (77.7%), and cookie (82.4%).  PCA explained that Keumkang is suitable for superior bread, while Uri is good for cooked noodles and cookies.

This study was performed to identify how the different levels of nitrogen application affected the variances of gluten properties and end-use qualities and the differences of variances among Korean wheat cultivars.  Protein and dry gluten content, SDS sedimentation volume and water absorption of Mixolab increased as nitrogen application increased.  This ratio of the increase was higher in Korean wheat cultivars for bread than in Korean wheat cultivars for noodles and cookies.  The proportion of (α+β)-gliadin measured by reversed-phase high-performance liquid chromatography (RP-HPLC) increased, but the proportion of ω- and γ-gliadin decreased as the protein content increased.  The Korean wheat cultivars for bread showed a high proportion of (α+β)-gliadin increase, the Korean cultivars for noodles had a high proportion of γ-gliadin decrease and the Korean wheat cultivars for cookies had a high proportion of ω-gliadin decrease.  However, there was no variation of the component in the proportion of glutenin component measured by RP-HPLC, even though the protein content was increased, but all of the protein fractions measured by size exclusion (SE)-HPLC were increased.  The soluble monomeric protein showed a high proportion of Korean wheat cultivars for bread by the increase of protein content.  Bread loaf volume increased by the increase of protein content but there were no variances in the ratio of increase among Korean wheat cultivars.  The cookie diameter decreased with the increase of protein content, and this ratio of decrease was the highest in Korean wheat cultivars for cookies.  The hardness of cooked noodles also increased by the increase of protein content but there were no variations in springiness and cohesiveness.  The decrease proportion of ω-gliadin affected the increase of bread loaf volume, the hardness of cooked noodles, and the decrease of cookie diameter.