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ARS Home » Plains Area » Fargo, North Dakota » Edward T. Schafer Agricultural Research Center » Cereal Crops Research » Research » Publications at this Location » Publication #320914

Research Project: Enhancement of Hard Spring Wheat, Durum, and Oat Quality

Location: Cereal Crops Research

Title: Effects of kernel vitreousness and protein level on protein molecular weight distribution, milling quality, and breadmaking quality in hard red spring wheat

Author
item Baasandorj, Tsogtbayar - North Dakota State University
item Ohm, Jae-bom
item Simsek, Senay - North Dakota State University

Submitted to: Cereal Chemistry
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/21/2016
Publication Date: 7/11/2016
Publication URL: http://handle.nal.usda.gov/10113/62816
Citation: Baasandorj, T., Ohm, J.-B., Simsek, S. 2016. Effects of kernel vitreousness and protein level on protein molecular weight distribution, milling quality, and breadmaking quality in hard red spring wheat. Cereal Chemistry. 93(4):426-434.

Interpretive Summary: Dark, hard, and vitreous kernel content is an important grading characteristic for hard red spring (HRS) wheat in the U.S. High protein content (PC) has been known to account for the compact structure with low volume of void space in vitreous endosperm. However, wheat samples which show large variation in KV at similar levels of wheat PC are identified in HRS wheat. This research aimed to determine the associations of kernel vitreousness (KV) with protein size (molecular weight) distribution (MWD) and quality traits that were not biased by quantitative variation of total proteins in HRS wheat. For this, HRS wheat samples that were collected from the U.S. Regional Crop Quality Survey for three consecutive growing years were especially composited for combination of three levels of KV and three levels of wheat PC and analyzed for protein composition and quality traits. Results indicated that KV level had significant effect on variation in quality traits such as test weight, break flour yield, and damaged starch content indicating that its associations with those traits might be independent of PC level. KV appeared to supplement PC in determination of optimum water levels required in breadmaking using milled flour samples. Protein MWD were determined by an analytical method called 'size exclusion HPLC.' Among the protein fractions analyzed by size exclusion HPLC, the protein fraction, high molecular weight (HMW) polymeric proteins that were not extractable by sodium dodecyl sulfate (SDS) buffer solution had significant and positive association with KV. Specially, SDS -unextractable HMW polymeric proteins altogether with kernel hardness parameter were identified to be major components associating with KV in this research. The results from this research indicated that SDS-unextractable HMW polymeric proteins could contribute to forming continuous protein matrix in endosperm. On the other hand, the tight adhesion between starch granule and surrounding protein matrix could be associated with kernel hardness as well as KV. Therefore, from the findings in this study, we conclude that storage proteins, specifically SDS-unextractable HMW polymeric proteins, and the factor related to kernel hardness altogether contribute to forming continuous, dense, and vitreous endosperm structure, hence, influencing interactively associations between KV and quality traits observed in this research. This information will help to segregate HRS wheat samples in breeding program and milling and baking industry.

Technical Abstract: Dark, hard, and vitreous kernel content is an important grading characteristic for hard red spring (HRS) wheat in the U.S. This research aimed to determine the associations of kernel vitreousness (KV) with protein molecular weight distribution (MWD) and quality traits that were not biased by quantitative variation of total proteins in HRS wheat. For this, HRS wheat samples that were collected from the U.S. Regional Crop Quality Survey were especially composited for combination of three levels of KV and three levels of wheat protein content (PC) for three consecutive growing years. Analysis of variance showed that KV level had a significant (P<0.001) effect on variation in test weight, break flour yield, and damaged starch content independently of PC level. Regression analysis indicated that KV could supplement PC for determination of water absorption in breadmaking. Among protein MWD parameters analyzed by size exclusion HPLC, the high molecular weight (HMW) polymeric proteins in SDS buffer unextractable fraction had significant (P<0.01) association with KV that was also independent of protein quantitative variation. Specially, SDS-unextractable HMW polymeric proteins altogether with kernel hardness parameter were identified to be major components to associate with KV by a stepwise multiple regression.