Location: Grain Quality and Structure Research2011 Annual Report
1a. Objectives (from AD-416)
Over the next 5 years, the following specific objectives will be addressed: Objective 1: Determine the biochemical and macro-molecular properties of hard winter wheat protein and starch responsible for end-use quality. • Sub-objective 1A: Correlate the physicochemical properties of hard winter wheat starch to end-use quality. • Sub-objective 1B: Determine the physicochemical properties of hard winter wheat proteins responsible for end-use quality. Objective 2: Identify specific genes and glutenin alleles associated with superior hard winter wheat quality and end-use functionality, in cooperation with wheat breeders and geneticists. • Sub-objective 2A: Evaluate the effects of glutenin allelic variation on dough mixing, bread-making and other properties in U.S. hard winter wheat. • Sub-objective 2B: Identify candidate genes, alleles or allelic combinations (with emphasis on gliadins) responsible for end-use functionality of U.S. hard winter wheat. Objective 3: The USDA-ARS Hard Winter Wheat Quality Laboratory (HWWQL) will define, evaluate, and screen the intrinsic end-use quality of hard winter wheat progenies in the Great Plains growing region to enhance germplasm and cultivar development. • Sub-objective 3A: Evaluate and screen the quality attributes of hard winter wheat experimental breeding lines and improve quality of existing hard winter wheat cultivars for end-product quality of world’s wheat-based staples, such as bread (whole wheat), tortillas, noodles and other products desired by customer markets. • Sub-objective 3B: Coordinate and conduct essential hard winter wheat projects of national importance, such as Wheat Quality Council (WQC), Overseas Varietal Analysis (OVA) and Regional Performance Nursery (RPN) for improvement of U.S wheat quality.
1b. Approach (from AD-416)
This project will involve a multidisciplinary approach to identify the physical and biochemical components of hard winter wheat that contribute to functionality, with the goal of identifying specific wheat proteins and starches with unique characteristics and functional interactions. Utilizing the Hard Winter Wheat Quality Laboratory (HWWQL) relational database the importance of candidate genes and loci on quality parameters will be investigated and allelic combinations will be correlated to end-use functionality (e.g. dough mixing, bread making and other properties) of hard winter wheat. In addition we will evaluate the intrinsic end-use quality of hard winter wheat progenies for wheat breeding programs in the hard winter wheat Great Plains growing area. Wheat attributes desired by both domestic and international customers will be determined using rapid and objective methods for estimating/predicting textural and quality differences from: (a) small samples (< 10 g) in early generation hard winter wheat breeding lines to promote efficient selection of hard winter wheat lines for needed-quality bases, which would result in the possibility of shortening the breeding program by 1-2 years without sacrificing intrinsic quality evaluation efforts; and (b) from commercial hard winter wheats to enhance the marketing system based on intrinsic quality and determine and evaluate quality parameters directed toward uses of hard winter wheats in non-bread products such as tortillas and Asian noodles, to promote U.S. hard winter wheats in the domestic and export markets.
3. Progress Report
This project falls under National Program 306, “Quality and Utilization of Agricultural Products”. Goals of NP 306 include “maintaining the quality” of U.S. crops, “enhancing their marketability,” and “expanding domestic and global market opportunities.” Research in this project is directed at identifying grain traits responsible for end-use functionality to improve the quality of wheat flour. The objectives of this project are very important and relevant to the scientific community, customers and stakeholders (breeders, farmers, the food industry and export markets). Both fundamental and applied approaches are carried out to expand our knowledge on how compositional attributes contribute to winter wheat functionality, as well as provided new approaches to characterize wheat components. Research for Objective 1 continued to concentrate on targeting the major constituents of flour (i.e. starch and protein) individually as well as part of a component system. Starch constitutes the greatest weight portion of the wheat endosperm (65-75%), and contributes functional qualities such as texture, volume, consistency, aesthetics, moisture, and shelf stability to various baked products. Similarly, storage proteins have been studied in great detail generally after a purification scheme. Current research is an integrated approach to determine the contributions of the major biochemical and components and their interactions that occur when flour is transformed into dough. We are focusing our efforts in identifying hard winter wheat lines grown under dry land and irrigated regimes, identical varieties resulting in a 2-3 % difference in protein content. We have identified 5 varieties that fall into that protein variance of which we will isolate starch for starch size distribution analysis, correlation to all aspects of bake quality and environmental conditions. Growing season 2011 saw a severe drought in Texas, Oklahoma and parts of Kansas, providing a unique opportunity to study these severe environmental effects on starch quality and quantity. The fine structure of starch (amylose-amylopectin ratios) is of critical importance in regard to end us functionality of food products. Few methods exist that enables researchers to screen large populations of starch for changes in amylose-amylopectin ratios, either due to genetic variability or environmental issues. Our goal was to completely solubilize cereal starch, with wide variations in amylopectin (100-0%) and attain reproducible HPSEC chromatographs. We have been able to solubilize maize, potato and sorghum starch with excellent results; we are just beginning our work on waxy and normal wheat starch. The functions of the Hard Winter Wheat Quality Laboratory (HWWQL) (Objective 3), provides critical information to the plant breeding community and both the domestic as well as international markets. This information is essential for the continued success of the HWW industry. Real-time wheat quality data is being provided during the 2011 harvest to Plains Grains Inc. and updated weekly online for potential buyers.
1. Objective methods to predict tortilla quality. Currently, the suitability of wheat lines for tortilla production is done by milling the wheat, evaluating the flour and processing it into tortillas. Moreover, it requires at least 1 kg of flour to do all of the tests. This makes screening wheat lines developed by breeders time-consuming, labor-intensive and costly. Developing prediction methods is one approach to make this screening process more efficient. ARS researchers at Manhattan, KS, developed models to predict tortilla diameter from any given flour from the mixing time and dough resistance to extension values and insoluble flour protein. A strong negative correlation between flour insoluble protein content and tortilla quality substantiates that flour properties required for good quality tortillas and breads are quite different and thus research continues to define the flour parameters for tortilla quality. These prediction models will be an easy and fast tool for breeders to advance or eliminate wheat lines specifically to breed for tortilla production.
2. Dissecting the genetic basis of bread making quality. The effect of different wheat flour proteins on bread-making properties is poorly characterized, particularly in U.S. breeding programs. ARS researchers at Manhattan, KS, evaluated mixing properties and protein composition of a set of 424 advanced hard winter wheat lines that represent the variability of the current hard winter wheat within the Great Plains. They showed that a particular combination of proteins had a significant effect on mixing time - some were associated with longer mix times, while others were associated with shorter mix times. Being able to identify the effects of variation in wheat storage proteins on dough properties and end products will definitely be of benefit not only to the breeding community, but also provide key insight to the keys for quality.
Jonnala, R.S., Macritchie, F., Smail, V.W., Seabourn, B.W., Tilley, M., Lafiandra, D., Urbano, M. 2010. Protein and quality characterization of complete and partial near isogenic lines of waxy wheat. Cereal Chemistry. 87(6):538-545.