Author
Ohm, Jae-Bom | |
ROSS, A - OREGON STATE UNIV. | |
PETERSON, C - OREGON STATE UNIV. | |
Morris, Craig |
Submitted to: Cereal Chemistry
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 9/15/2008 Publication Date: 3/1/2009 Citation: Ohm, J., Ross, A.S., Peterson, C.J., Morris, C.F. 2009. Relationships of Quality Characteristics with Size Exclusion HPLC Chromatogram of Protein Extract in Soft-White Winter Wheats. Cereal Chemistry 86:(2) 197-203 Interpretive Summary: This study investigated relationships between size of native grain proteins and grain, flour, and end-use quality characteristics of soft white winter wheats grown in Oregon. Wheat proteins were separated by size exclusion HPLC (SE-HPLC) their relationships with end-use quality characteristics were studied. The results indicated that size distribution of proteins significantly affects quality characteristics. Specifically, protein fractions that have very large size appeared to have a detrimental effect on soft wheat quality. The high content of the protein fractions appeared to increase kernel hardness, mixing water absorption and gluten strength and decrease break flour yield, cookie diameter, and cake volume. Contrastingly, higher proportions of specific soluble monomeric protein fractions were identified to enhance soft wheat quality, including milling and baking characteristics. The size distribution of proteins analyzed by SE-HPLC was applied to predict quality of soft white wheats and the results indicated that the SE-HPLC data could be used to predict soft wheat quality characteristics such as mixograph water absorption, and cookie diameter and thickness. Technical Abstract: This study investigated relationships between molecular weight distributions of unreduced grain proteins and grain, flour, and end-use quality characteristics of soft white winter wheats grown in Oregon. Absorbance area and area % values of protein fractions separated by size exclusion HPLC (SE-HPLC) showed significant correlations with quality characteristics, indicating associations of molecular weight distributions of proteins with quality characteristics. Specifically, high molecular weight polymeric protein fractions appeared to have a detrimental effect on soft wheat quality. This was shown by significant positive correlations with single kernel hardness index, and mixograph water absorption and tolerance, and negative correlations with break flour yield, cookie diameter, and cake volume. Higher proportions of soluble monomeric proteins eluted after the main gliadin peak, were observed to enhance soft wheat quality due to negative associations with single kernel hardness index and mixograph water absorption and tolerance, and positive associations with break flour yield, cookie diameter, and cake volume. Calibration models were developed by the application of multivariate analyses to the SE-HPLC data. These explained over 90 % of the variation in mixograph water absorption, and cookie diameter and thickness. |