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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 #213062
Title: Distribtuion of Protein Composition in Bread Wheat Flour Mill Streams and Reltationship to Breadmaking Quality

Author
item WANG, Y. - NORTH DAKOTA STATE UNIV.
item KHAN, K. - NORTH DAKOTA STATE UNIV.
item Hareland, Gary
item NYGARD, G. - NORTH DAKOTA STATE UNIV.

Submitted to: Cereal Chemistry
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/20/2007
Publication Date: 6/1/2007
Citation: Wang, Y.G., Khan, K., Hareland, G.A., Nygard, G. 2007. Distribtuion of Protein Composition in Bread Wheat Flour Mill Streams and Reltationship to Breadmaking Quality. Cereal Chemistry. 84:271-275.

Interpretive Summary: Wheat protein quantity and composition are important parameters for wheat baking quality. The objective of this study was to separate the protein of different flour mill streams into various protein sub-fractions, observe and compare the distribution of these sub-fractions, and establish a relationship between protein composition and breadmaking quality. The hard red winter wheat cultivar Nekota was milled in an experimental mill from which three break and three reduction flours were obtained. Patent flour was made by combining representative fractions of the break and reduction flours. For each mill steam and patent flour, flour proteins were separated into monomeric and polymeric protein sub-fractions. The protein sub-fractions included gliadin, albumin+globulin, and high and low molecular weight gluten subunits. The sub-fractions were statistically analyzed and were found to be significantly different among the flour mill streams. The ratio of polymeric to monomeric proteins in break flour streams was significantly greater than in the reduction flour streams. The relationship between protein composition and breadmaking quality showed that the quantities of total flour protein, albumin+ globulin, and high and low molecular weight gluten subunits in flour were significantly and positively correlated with bread loaf volume. However, the ratio of high to low molecular weight gluten subunits had little association with loaf volume. The gliadin content in total flour protein was negatively and significantly correlated with loaf volume. These results indicated that the quantity and composition of protein among the mill streams was different, which resulted in differences in breadmaking quality.

Technical Abstract: Wheat protein quantity and composition are important parameters for wheat baking quality. The objective of this study was to use fractionation techniques to separate the proteins of flour mill streams into various protein fractions, to examine the distribution of these protein fractions, and to establish a relationship between protein composition and breadmaking quality. Nine break streams, nine reduction streams, and three patent flours obtained from three samples of Nekota (a hard red winter wheat) were used in this study. A solution of 0.3M NaI + 7.5% 1-propanol was used to separate flour protein into monomeric and polymeric proteins. The protein fractions, including gliadin, albumin+globulin, HMW-GS, and LMW-GS, were precipitated with 0.1M NH4Ac-MeOH or acetone. The fractions were statistically analyzed for their distribution in the mill streams. The quantities of total flour protein and protein fractions in flour were significantly different among mill streams. The ratio of polymeric to monomeric proteins in break streams was significantly greater than in the reduction streams. The relationship between protein composition and breadmaking quality showed that the quantities of total flour protein, albumin+ globulin, HMW-GS, and LMW-GS in flour were significantly and positively correlated with loaf volume. The ratio of HMW-GS to LMWGS had little association with loaf volume. The gliadin content in total flour protein was negatively and significantly correlated with loaf volume. These results indicated that the quantity and composition of protein among the mill streams was different, and this resulted in differences in breadmaking quality.