Submitted to: Cereal Chemistry
Publication Type: Peer reviewed journal
Publication Acceptance Date: 8/21/2006
Publication Date: 3/1/2008
Citation: Ohm, J., Ross, A., Peterson, J., Ong, Y. 2008. Relationship of high molecular weight glutenin subunit composition and molecular weight distribution of wheat flour protein with water absorption and color characteristics of noodle dough. Cereal Chemistry. 85:(2)123-131 Interpretive Summary: Noodle doughs were made from hard white winter wheat flours from Oregon using optimum water amounts that gave good dough texture for processing. Colors of those noodle doughs were measured. Statistical analysis indicated that noodle doughs that required more water had lower brightness and yellowness, but higher redness. Wheat varieties with higher kernel hardness required more water to make noodles without any significant effect on color parameters. Protein was observed to be the main flour component that affects optimum water needed for noodle making and noodle dough color. Protein subunits with high molecular weight affected all measured noodle parameters except for brightness just after noodle sheeting. Statistical analysis indicated that protein subunits with high molecular weight (i.e., larger proteins) had a greater effect on amount of water needed and redness of noodle dough. Protein subunits which are called HMW-GS 17+18 were found to increase significantly the optimum amount of water needed to make noodle dough and its redness. The size distribution of protein molecules of flour affected noodle parameters. Protein fractions that were observed to increase redness decreased yellowness of noodle dough. The results obtained from this research indicate that variations in protein molecular weight distribution in flour can be used to predict color of noodle doughs for selection of varieties in wheat breeding programs.
Technical Abstract: Colors of noodle doughs made from hard white winter wheat flours from Oregon were measured at optimum noodle water absorptions (NWA). Partial correlations, removing effect of protein concentration, indicated that NWA had negative relationships with 0 hr L* and 24 hr b*, and positive relationships with 0 and 24 hr a*. Kernel hardness index had positive simple and partial correlations with NWA without any significant (p<0.05) correlation with color parameters. High molecular weight glutenin subunits (HMW-GS) significantly (p<0.05) affected all measured noodle parameters except for 0 hr L*. Covariance analysis, using protein concentration as a covariate indicated that HMW-GS significantly affected NWA and a* (p<0.01). Wheat varieties with HMW-GS 17+18 showed significantly higher mean NWA, and a* values, than those with alternative Glu-B1 subunits. Protein molecular weight distributions affected noodle parameters, as shown by significant correlations with absorbance areas and % areas of protein size exclusion (SE) HPLC chromatograms. Protein fractions that had positive correlations with redness had negative correlations with yellowness. Applying multivariate analyses to SE-HPLC data to derive calibration models to predict fresh noodle dough a* and b* values had R2 values higher than 0.91 and cross validations had R2 values higher than 0.75.