Location: Cereal Crops Research2011 Annual Report
1a. Objectives (from AD-416)
The ultimate goal is to enhance the quality of U.S. wheat for domestic and overseas markets. Objectives are to: identify milling, baking, and pasta processing traits of experimental and advanced lines of hard spring and durum wheat that impact end-use quality and the overall development and release of new commercial cultivars of wheat; and identify specific biochemical components in wheat that are associated with end-use baking quality traits. More specifically, the latter objective includes: to develop rapid methods to characterize proteins, which are initially important for predicting end-use quality; to determine the variation in free asparagine content in wheat, which is an important precursor for the formation of carcinogenic acrylamide during bread baking and toasting; and to identify the efficacy and impact of sulfur fertilization on end-use baking quality of hard spring wheat.
1b. Approach (from AD-416)
Approximately 4000 hard spring and 1000 durum wheat experimental lines will be submitted by Federal, State, and private breeders, and special interest groups on an annual basis and evaluated for end-use quality. Wheat will be obtained from different generations of development in specific breeding programs, which will include early-generation, preliminary, and advanced lines and include commercial cultivars as controls. Measureable end-use quality traits include test weight, size, seed weight, sprout damage, physical evidence of disease, and protein and ash content; milling performance as a function of flour and semolina yield; flour and semolina color, protein, and ash content; dough strength properties; bread baking quality; and pasta processing quality. The Fargo Genotyping Laboratory will identify quantitative trait loci regions associated with end-use quality, primarily kernel and dough strength traits on selected hard spring wheat samples. Research will be conducted on the rapid characterization of protein extracts from wheat and flour by testing two different protein extraction methods. Variation in free asparagine content in wheat lines will be measured. The efficacy and impact of sulfur fertilization on end-use baking quality of hard spring wheat, specifically protein composition and amino acid profiles, will be determined as a function of dough strength characteristics.
3. Progress Report
This project continues research from Project 5442-43440-008-00D Enhance Hard Spring and Durum Wheat Quality and Utilization. The Hard Red Spring Wheat Quality Laboratory (WQL) analyzed the physical and biochemical quality traits on over 4000 samples of hard spring and durum wheat that were submitted by private and public wheat breeders involved in improving wheat germplasm and by scientists involved in gene mapping to identify chromosome regions harboring genes that influence end-quality traits. The WQL, in cooperation with the Wheat Quality Council (WQC), evaluated twelve experimental lines of hard spring wheat that were grown at up to 5 locations. The WQL tested each line for kernel, milling, flour, dough, and baking quality traits; coordinated the baking quality test results from 9 independent public and private testing laboratories; and analyzed the data and published the results that were presented and discussed at the annual meeting of the WQC in 2010. WQL interaction with the WQC serves to provide industry feedback on milling and baking quality traits of advanced experimental lines of wheat that are considered for release into commercial production. Rapid characterization of polymeric proteins in flour is important for wheat breadmaking quality evaluation. We tested a micro bore column for analysis of polymeric proteins that were extracted from hard spring wheat flour. The procedure using a microbore column appears to enhance the speed of analysis of polymeric protein for wheat quality evaluation with decreased consumption of hazardous organic solvents. We also tested UV spectroscopy for rapid characterization of protein extracts and identified wavelengths of which absorbance data might be important for quality evaluation based on their correlations with flour breadmaking properties. Since free asparagine is a precursor for the formation of carcinogenic acrylamide during bread baking and toasting, segregation of wheat lines that have low asparagine concentration is important. We tested two solutions to extract free amino acids in wheat for analysis of asparagine using a gas chromatography system and selected a hot ethanol solution due to the higher stability in amino acid concentration during extraction. We analyzed 48 wheat lines grown in two locations in ND for free amino acids. The mixolab is a new empirical instrument that measures dough rheology characteristics under thermal constraints as well as mixing properties. The mixolab profile was divided into six different stages, and torque measurements of individual stages were modeled by nonlinear curve fitting using a combination of genetic algorithms and multidimensional unconstrained nonlinear minimization. Novel parameters were extracted from the fitted equations. The mixolab parameters are being further tested to determine if they can be employed to develop prediction models of breadmaking characteristics in cooperation with the wheat breeding program at South Dakota State University. The new mixolab parameters will result in improvement of objective evaluations of flour dough thermal characteristics that also will be helpful for evaluation of flour bread making quality.
1. Development of improved wheat germplasm. Wheat producers, milling and baking industries, and overseas customers require high standards in the quality of wheat to meet their evolving needs. ARS researchers in Fargo, ND contributed wheat end-use quality data that helped lead to the development of improved wheat germplasm and subsequent release of new cultivars of spring and durum wheat bred for commercial production. They provided over 40 different tests related to the physical and biochemical quality traits of the wheat kernel and related milling performance, flour, semolina, dough, baking, and spaghetti processing on over 4000 samples of hard spring, and durum wheat lines that were submitted by public and private wheat breeders and cooperating scientists. As a result, new spring wheat cultivars were released in 2009/10 that provide farmers, industry, and consumers with high quality wheat.
2. Quality of refrigerated dough made from hard red spring wheat. Products obtained from refrigerated doughs account for greater than $1.7 billion per year in sales in the US, and they are one of the fastest growing segments of the ready-to-use, grain-based food industry. Refrigerated storage of bread dough products can result in undesirable dough syruping (water separation). ARS researchers in Fargo, ND, in collaboration with North Dakota State University, investigated the effects of wheat cultivar and growing environment on dough syruping during refrigerated storage in relation to xylanase activity (a plant cell wall or sugar degrading enzyme activity) in hard red spring wheat. They discovered that growing environment had a greater impact on enzyme activity and dough syruping than cultivar of wheat. Some cultivars were consistently lower in apparent enzyme activity and dough syruping across all growing environments. The results indicate that certain cultivars grown in relatively dry environments across the prime hard red spring wheat growing region can be used in refrigerated dough formulations. This information will help millers and wheat breeders segregate cultivars for refrigerated dough production.Simsek, S., Whitney, K.L., Ohm, J., Anderson, J., Mergoum, M. 2011. Refrigerated Dough Quality: Effect of Environment and Genotypes of Hard Red Spring Wheat. Journal of Food Science. 76:S101-S107.