Location: Cereal Crops ResearchTitle: Variation of protein MWD parameters and their associations with free asparagine concentration and quality characteristics in hard red spring wheat
|SIMSEK, SENAY - North Dakota State University|
|MERGOUM, MOHAMED - University Of Georgia|
Submitted to: Journal of Cereal Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/27/2017
Publication Date: 1/1/2018
Citation: Ohm, J., Simsek, S., Mergoum, M. 2018. Variation of protein MWD parameters and their associations with free asparagine concentration and quality characteristics in hard red spring wheat. Journal of Cereal Science. 79:154-159.
Interpretive Summary: Asparagine is one of the amino acids that plants and animals use as a building block to synthesize proteins. However, free asparagine in starchy foods can react with other compounds during baking to form acrylamide, a suspected carcinogen. Reduction of free asparagine concentration in wheat is therefore desirable in order to reduce the formation of potentially harmful acrylamide during baking. This research was performed to determine possible associations between protein size distribution, bread-making quality, and free asparagine concentration in hard red spring wheat grown in North Dakota. Among wheat proteins, the protein fractions known as polymeric proteins are much larger in size than other protein fractions. Significant associations were found between polymeric proteins and free asparagine concentration as well as with bread-making quality characteristics. Specifically, polymeric proteins that are not soluble in sodium dodecyl sulfate solution were found to have a positive influence on wheat bread-making quality characteristics. Free asparagine concentration was negatively associated with the proportion of insoluble polymeric proteins in total proteins. Overall, the results indicate that insoluble polymeric protein parameters might be useful as indirect indexes to screen wheat varieties for low free asparagine concentration as well as for improvement of bread-making quality in hard red spring wheat breeding.
Technical Abstract: This research was performed to determine variation of protein molecular weight distribution (MWD) parameters using size exclusion HPLC and their associations with quality characteristics and free asparagine concentration (FAC) using eleven hard red spring (HRS) wheat genotypes grown at three locations in North Dakota. The FAC in wheat is better be reduced since it is a precursor to form carcinogenic acrylamide during baking. Among MWD parameters, the polymeric proteins of SDS unextractable proteins were identified to be useful in screening HRS wheat genotypes for low FAC and improvement of bread-making quality characteristics. The ANOVA indicated that growing locations and genotypes significantly (P<0.01) influenced variation of unextractable polymeric protein parameters while effect of genotype by location interaction was non-significant (P>0.05). The quantity of unextractable polymeric proteins had significant and positive genotypic correlations (rg) with quality characteristics including mixograph pattern (rg =0.87, P<0.01) and bread loaf volume (rg =0.86, P<0.01). The percent of unextractable polymeric proteins based on total protein had a negative correlation with FAC (rg=-0.92, P<0.01). The covariate-effect biplot analyses also supported that the genotypic variations were primarily associated with correlations of unextractable polymeric protein parameters with mixograph pattern, bread loaf volume, and FAC.