Location: Corn, Soybean and Wheat Quality Research
2019 Annual Report
Objectives
Objective 1: Develop accurate and efficient laboratory methods for end-use quality evaluation of soft winter wheat breeding lines and varieties. Sub-objective 1a: Improve the cake baking test procedure of non-chlorinated flour by identification of ways to increase cake volume. Sub-objective 1b: Determine the feasibility of flour batter and extract viscosities for prediction of the cake baking quality potential of wheat flour.
Objective 2: Establish quality characteristics of soft winter wheat non-conventional and whole grain food products and enable new and/or expanded commercial uses. Sub-objective 2a: Identify the quality traits of eastern soft winter wheat required for making steamed bread. Sub-objective 2b: Determine variation in the characteristics of soft wheat bran among wheat varieties, and identify ways to improve the functional properties of bran for making whole grain soft wheat foods with improved product quality and sensory acceptance. Sub-objective 2c: Develop eastern soft wheats with different complements of waxy alleles.
Objective 3: Identify the biochemical, physical and genetic factors associated with flour yield and endosperm separation from bran during milling. Sub-objective 3a: Determine the variation in bran micro-structural characteristics and remnant endosperm among soft wheat genotypes in relation to flour yield. Sub-objective 3b: Evaluate effect of TaSus2 alleles at QTL on chr. 2B on milling yield and flour quality. Sub-objective 3c: Compare expression of TaSus2-2B transcripts in near-isogenic lines carrying different complements of HapL, HapH and HapG.
Objective 4: Congressionally designated as a direct mission of service, and non-hypothesis driven, the USDA-ARS will identify, evaluate, and screen the intrinsic end-use quality to enhance cultivar development.
Approach
Sub-Objective 1a: Evaluate the cake baking performance of non-chlorinated flour with heat and/or acid pretreatments. Determine the effects of waxy, cold water swelling and pre-gelatinized starches on the cake baking performance of non-chlorinated flour. Establish an improved cake baking method and validate its effectiveness. Conduct a collaborative study for the established cake baking method with the AACCI Soft Wheat Flour Technical Committee (SWFTC). Sub-Objective 1b: Determine the viscosities of cake batter, simplified batter and aqueous flour extract using various viscosity tests. Determine the relationships between batter and flour extract viscosity, and cake quality attributes. Establish the batter or extract viscosity test as a routine test of flour for cake baking quality. Sub-Objective 2a: Determine the flour characteristics of soft red winter wheat varieties important for making steamed bread. Determine the quality of steamed breads prepared from soft red wheat flours. Determine the influences of protein and starch characteristics on steamed bread quality. Develop a quality profile of soft red wheat flour for making steamed bread. Sub-Objective 2b: Determine the variation in characteristics of bran among soft red winter wheat varieties. Evaluate the quality of whole grain biscuits and pancakes prepared from a blend of wheat flour and bran from different varieties. Identify bran characteristics of soft red wheat affecting whole wheat biscuits and pancakes. Improve functional properties of bran. Sub-objective 2c: Waxy alleles from fully and partial waxy lines will be introgressed into regionally grown, good milling soft red and white winter wheats to produce lines needed for testing the role of high amylopectin flours on the quality of conventional and non-conventional soft wheat products. Sub-objective 3a: Evaluate the starch content of bran as an estimate of remnant endosperm on bran. Determine the residual endosperm content of bran as an indicator of endosperm separation efficiency. Determine arabinoxylan content of residual endosperm of bran. Evaluate the microstructural differences of bran of contrasting remnant endosperm content. Sub-objective 3b: HapH and HapG alleles will be introgressed by three backcrosses to the recurrent parent. Seed will subsequently be increased for field trials. Sub-objective 3c: We will characterize the sequence and expression of TaSus2-2B to determine if there is a correlation between gene structure and/or expression and high flour yield and kernel softness. Goal 4: Annually evaluate over 6,000 soft red and white wheat grain samples for milling and baking quality from about 21 public and private wheat breeding programs in the eastern half of the United States. Wheat grain samples are classified into ‘preliminary’, ‘intermediate’ or ‘advanced’ groups, depending on the stage of breeding generation and the intensity of quality evaluation needs, and evaluated for their end-use quality potential using AACCI Methods and established procedures.
Progress Report
This project develops accurate and reliable quality testing methods, identifies the biochemical and genetic traits of wheat for improved end-use quality and extended uses, and contributes to the development of wheat varieties by conducting the end-use quality evaluation of wheat breeding lines.
An experimental high ratio cake baking method applicable to wheat flour without prior flour chlorination was presented to the American Association of Cereal Chemists International (AACCI) Soft Wheat and Flour Products Technical Committee to obtain approval of the validity of the method and to initiate a preliminary collaborative study. The cake baking method was developed in the previous years of the project by modifying the formula of the AACCI approved method for chlorinated flour with the employment of a fixed water level and reduced batter mixing steps. Three collaborators covering various elevations and barometric pressures were recruited for a preliminary collaborative test of the cake baking method; three flour samples with varying cake baking potentials and all the cake baking ingredients were obtained and distributed to the collaborators; and the performance of the cake baking method and the effects of elevation on cake quality attributes were evaluated to identify the optimal baking powder level at each elevation.
To examine the feasibility of flour-water and flour-water-sugar batter viscosities in the estimation of wheat flour quality for making cakes, cakes were baked from 20 wheat flours of varying biochemical characteristics with or without prior flour chlorination and their quality attributes were determined. The viscosities of flour-water and flour-water-sugar batters were determined using both a consistometer and a rapid visco analyzer, and were expressed as flow distance and resistance to stirring, respectively. The quality attributes of cakes were related to the flour batter viscosity measurements, with correlations between the rapid visco analyzer viscosities of flour-water batter and cake volumes ranging from -0.61 to -0.67, indicating that the viscosity of wheat flour-water batter could give an estimate of wheat flour quality for making cakes.
The influences of high molecular weight-glutenin subunits and rye translocations on cookie-baking quality were investigated. Fifty eastern soft winter wheat varieties carrying varying protein strengths, subunit compositions and rye translocations were analyzed for flour characteristics and sugar-snap cookie baking quality, and the associations of subunit composition and rye translocations with protein strength and cookie baking quality of eastern soft wheat were identified.
The influence of bran characteristics on the quality attributes of whole wheat pancakes and baking powder biscuits were studied. The purified brans of 17 soft red winter wheat varieties were analyzed for composition (including protein, starch, dietary fiber, phytate, phenolics and arabinoxylans) and physical characteristics, and the quality of whole wheat pancakes and baking powder biscuits prepared from the blends of those brans and wheat flours was determined. The bran compositional characteristics desirable for making whole wheat pancakes and baking powder biscuits were identified by comparing the compositional and physical characteristics of bran and the quality attributes of whole wheat pancakes and baking powder biscuits.
Wheat bran pretreatment methods, including heat, moisture and pressure, were examined for their ability to enhance the properties desirable for the production of whole wheat steamed bread. Wheat bran was pretreated using various hydrothermal and pressure methods (including hydration and autoclaving, roasting, jet-cooking, extrusion and high temperature-high pressuring cooking), the changes in hydration properties and composition were determined, and the optimal water absorption and dough preparation methods for making whole wheat steamed bread from wheat flour and bran blends were identified. The effects of bran pretreatments on composition, physical characteristics of bran, dough water absorption and mixing properties and steamed bread quality were elucidated. The advantages of initially mixing dough only with refined flour and gluten, and then adding pre-hydrated bran, were compared to the conventional all-at-once mixing method with regards to steamed bread quality.
In an effort to develop waxy and partial-waxy eastern soft wheat germplasms, continuous selection of waxy and partial-waxy homogeneous lines using three widely grown soft red winter wheat cultivars (Kristy, Milton and Wilson) was conducted using a combination of marker assisted selection, an endosperm iodine staining test and a granular bound starch synthase identification test. The selected partial-waxy and waxy homogeneous lines were planted in the field for seed increase and starch characterization, and selection of waxy and partial-waxy homogeneous lines from the backcrosses was continued.
Endosperm separation from bran during roller milling was identified as one of the major factors influencing the flour yield potential of wheat grain in our previous study. However, little is known about the endosperm characteristics governing its detachment from bran during roller milling. The biochemical characteristics of the outer endosperm associated with the degree of endosperm separation from bran during roller milling, and subsequently with flour yield, were identified. The biochemical compositions of the outer endosperm, flour and bran of ten soft red winter wheat varieties exhibiting a large variation in flour yield were determined, and their relationships with flour yield were explored in an effort to identify the components showing associations with endosperm separation from bran during roller milling of wheat grain.
In soft winter wheat our previous research found the chromosome region around TaSus2-2B may be involved in flour quality traits. To test the effects of TaSus2-2B expression on the starch synthesis pathway and ultimately yield and flour quality, we developed near isogenic lines in two genetic backgrounds, Coker 9152 and Kristy, with either their native low-expressing TaSus2-2B gene or a higher expressing TaSus2-2B gene from donor varieties Foster or Soissons. Markers unique to each version of TaSus2-2B were used to select lines through three back crosses to the parent and further self-fertilization of the near isogenic lines for 3 generations to bulk seed. Bulked seed from several near isogenic lines each for the Coker and Kristy backgrounds with the high or low expressing TaSus2-2B were grown in Wooster, Ohio, and East Lansing, Michigan, for testing of flour quality traits and yield. Reverse-transcribed quantitative polymerase chain reaction (RT-qPCR) of TaSus2-2B has been performed in the near isogenic lines showing higher expression in the donor alleles from Foster and Soissons as expected. The timing of highest TaSus2-2B expression was different between Coker 9152 and Kristy.
Preharvest sprouting reduces the value and marketability of wheat and occurs in the region about once every two years. We are investigating sources of resistance that can be bred into commercial wheat varieties from a diverse wheat population. A genome-wide association study with over 2000 markers placed on 189 diverse varieties was performed finding three potential locations of resistance in soft winter wheat. Further characterization is ongoing using four selected pairs of individuals. Each pair has the majority of the 2000 markers in common suggesting close genetic relationship, but one is tolerant to pre-harvest sprouting while the other is susceptible. Pedigree analysis indicates in three of the pairs that the two varieties share either a common parent or grandparent. These variety pairs likely have many genes in common but a few that are not and potentially involved in the differences in pre-harvest sprouting observed between the pairs. Ribonucleic acid sequencing at select, important timepoints is underway to find these candidate genes.
Finding genes involved in flour quality traits has proven difficult using standard methods. Six varieties have been chosen for testing based on their genetic relatedness from 2000 markers and their differences in flour quality traits from grow-outs at seven year-locations. Varieties that are genetically related but have differences in one or more flour quality traits will have a small number of different genes, some of which are related to flour quality and may be expressed differently. To find the differentially expressed genes, the varieties have been grown in the greenhouse and samples collected for future expression analysis at early grain filling 10 days post anthesis, mid grain filling 15 days post anthesis, and late grain filling 20 days post anthesis.
The milling and baking quality evaluation of appropriately 3,879 samples submitted by 13 public and private breeding programs of eastern soft winter wheat and state variety testing programs was performed. The test results were summarized and distributed to the breeding programs, directly contributing to the development of wheat varieties possessing superior quality. Collaborative research projects with eastern soft winter wheat researchers at five public universities that aimed to identify the genetic markers for milling and baking quality traits of eastern soft wheat were carried out by conducting comprehensive milling and baking quality evaluations. The Soft Wheat Quality Council (SWQC) annual evaluation of new varieties and advanced breeding lines was coordinated and carried out by milling grain, distributing flour to collaborators, performing quality trait evaluations and preparing a report that collates quality evaluations among the collaborators for presentation at the annual SWQC Meeting.
Accomplishments
1. Identification of protein composition of U.S. eastern soft wheat desirable for making cookies. Protein molecules, especially high molecular weight glutenin subunits (HMW-GS) and those introduced from rye, have a dominant influence on the processing and product quality of wheat and can be profiled easily using the existing genetic markers. Eastern soft wheat varieties vary widely in HMW-GS and rye protein compositions; however, the protein compositions desirable for making cookies have not been well established, leaving wheat breeders without an efficient screening tool for determining protein strength. By profiling 50 selected U.S. eastern soft winter (ESW) wheat varieties for HMW-GS and rye protein composition and determining their dough mixing properties and cookie-baking quality, ARS scientists in Wooster, Ohio, determined that wheat varieties different in HMW-GS and rye protein composition exhibit large variations in cookie baking quality, varieties carrying HMW glutenin subunit (2+121) are the most desirable for the production of cookies, and the influence of rye proteins on cookie diameter is dependent on HMW-GS profile. This information will greatly help soft wheat breeders with the screening of breeding lines in the early stage of the breeding process and cookie manufacturers with the selection of varieties possessing desirable cookie-baking potentials by simply determining the HMW-GS and rye protein profiles.
2. Identification of bran characteristics desirable for making whole wheat pancakes and biscuits. Bran particles present in whole wheat meal provide whole wheat foods with nutritional advantages, but are responsible for decreased product quality and taste, suggesting that bran characteristics should be considered when selecting wheat grain for the production of whole wheat foods. Little information on the bran characteristics of whole wheat grain suitable for making pancakes and baking powder biscuits is currently available. By analyzing the compositional characteristics of the purified brans of 17 soft wheat varieties, preparing pancakes and baking powder biscuits from the blends of those brans and two refined flours and evaluating them for quality, ARS scientists in Wooster, Ohio, determined that the brans of high protein content are desirable for making whole wheat pancakes, and that those of high protein and soluble dietary fiber contents, and low arabinoxylan and insoluble dietary fiber contents, are desirable for making whole wheat biscuits. Whole wheat meals containing brans of high protein content produced pancakes of comparable diameter to those made with refined flour. Whole wheat meals containing brans of high protein and soluble dietary fiber contents, and low arabinoxylan and insoluble dietary fiber contents, produced biscuits with intermediate-to-high height and low-to-intermediate shape factor. This information will help food manufacturers identify wheat grain with bran that is suitable for making desirable quality whole wheat pancakes and biscuits.
3. Wheat grain endosperm characteristics associated with its detachment from bran during milling. Endosperm separation from bran during roller milling was identified as one of the major factors influencing the flour yield potential of wheat grain in our previous study, while the outer endosperm characteristics governing its detachment from bran, which could serve as an effective screening tool of breeding lines for flour yield, has not been elucidated. By determining the biochemical compositions of the remnant endosperm of bran and milled flour, and their associations with flour yield, for ten soft winter wheat varieties exhibiting a large variation in flour yield, ARS scientists in Wooster, Ohio, discovered associations of the water-soluble arabinoxylan, water-insoluble arabinoxylan and beta-glucan contents of remnant endosperm with flour yield, and higher water-insoluble arabinoxylan and beta-glucan contents of remnant endosperm with wheat varieties of high flour yield potential than with varieties of low flour yield potential. These discoveries led to the conclusion that outer endosperm low in water-soluble arabinoxylan, and high in water-insoluble arabinoxylan and beta-glucan, facilitates the efficient detachment of endosperm from bran during roller milling, positively contributing to flour yield. The obtained information enhances our understanding of the grain characteristics affecting endosperm separation from bran during roller milling and identifies wheat grain traits that could be used as effective screening factors of breeding lines for flour yield.
4. Pretreatment of wheat bran for improved functionality and optimal dough mixing conditions for making steamed bread. Bran greatly contributes to the increased nutritional value of whole wheat foods, but is responsible for inferior product quality and sensory attributes. Improvement of the functional properties of bran by physical treatments before incorporation into whole wheat foods, and employment of the optimal preparation conditions of whole wheat foods could be promising strategies for mitigating the negative influences of bran particles on the quality and taste of whole wheat foods. ARS scientists in Wooster, Ohio, examined the functional property improvements of bran with various hydrothermal and pressure treatments and found increases in water absorption, solubility, and water retention capacity, a decrease in the insoluble fiber content and an increase in the soluble fiber content with autoclaving, roasting, jet-cooking and extrusion treatments. They also identified that the two-step process of premixing the dough of refined flour and gluten followed by incorporation of hydrated bran, compared to the one-step mixing of refined flour, gluten and bran, produced steamed bread of larger volume, higher specific volume and better crumb structure. The identified hydrothermal treatment conditions for the improvement of bran functional properties and the two-step dough preparation method provide food manufacturers with effective ways to improve whole wheat steamed bread quality and taste, and bear the potential to be readily applicable to other whole wheat foods.
5. Higher expression of TaSus2-2B in near-isogenic lines increased expression of other genes necessary to produce starch in the seed. TaSus2-2B is more highly expressed in the Foster and Soissons wheat varieties potentially due to a previously found large sequence deletion in the area regulating gene expression of the lower expressing TaSus2-2B genes in Coker 9152 and Kristy varieties. Increasing TaSus2-2B could increase seed starch milled to wheat flour. In Chinese spring wheat increased expression of TaSus2-2B was associated with increased 1000 kernel weight, a measure of yield. ARS scientists in Wooster, Ohio, identified the effect of the expression of TaSus2-2B on the expression of other genes in soft winter wheat. Of the genes found to be more highly expressed with higher TaSus2-2B expression, several genes were directly or indirectly involved in the synthesis of starch in the seed. A survey of 200 soft winter wheat lines found only 20% have the more highly expressed TaSus2-2B gene and others report similar numbers in other wheat classes. Breeding new U.S. wheat varieties with the more highly expressed TaSus2-2B gene could improve grain quality characteristics, which is beneficial to millers and growers.
Review Publications
Park, E., Fuerst, E., Baik, B.V. 2018. Effect of bran hydration with enzymes on functional properties of flour-bran blends. Cereal Chemistry. 96(2):273-282. https://doi.org/10.1002/cche.10119.
Okekeogbu, I.O., Pattathil, S., Gonzalez Fernandez-Nino, S.M., Aryal, U.K., Penning, B., Lao, J., Heazlewood, J.L., Hahn, M.G., McCann, M.C., Carpita, N.C. 2019. Glycome and proteome components of Golgi membranes are common between two angiosperms with distinct cell wall structures. The Plant Cell. https://doi.org/10.1105/tpc.18.00755.
Jeon, S., Baik, B.V., Kweon, M. 2019. Solvent retention capacity (SRC) application to assess soft wheat flour quality for making white-salted noodles. Cereal Chemistry. 96(3):497-507. https://doi.org/10.1002/cche.10150.
Ji, T., Penning, B., Baik, B-K. 2018. Pre-harvest sprouting resistance of soft winter wheat varieties and associated grain characteristics. Journal of Cereal Science. 83:110-115.
Dubat, A., Berra, M., Baik, B.V. 2019. Collaborative study report: Automated measurement of wheat flour solvent retention capacity with the Chopin-SRC Instrument (AACCI Approved Method 56-15.01). Cereal Foods World. https://doi.org/10.1094/CFW-64-3-0033.
Ma, F., Lee, Y., Baik, B.V. 2019. Bran characteristics influence the quality of whole wheat pancakes and baking powder biscuits. Cereal Chemistry. 96(3):497-507. https://doi.org/10.1002/cche.10159.
Ma, F., Kim, J., Cho, E., Brown Guedira, G.L., Park, C., Baik, B.V. 2019. HMW-GS composition and rye translocations of U.S. eastern soft winter wheat and their associations with protein strength. Journal of Cereal Science. https://doi.org/10.1016/j.jcs.2019.102799.
