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United States Department of Agriculture

Agricultural Research Service

Research Project: CHARACTERIZATION OF GRAIN BIOCHEMICAL COMPONENTS RESPONSIBLE FOR END-USE QUALITY

Location: Grain Quality and Structure Research Unit

2009 Annual Report


1a.Objectives (from AD-416)
Determine roles and interactions of the major biochemical components of cereals (starch, non-starch carbohydrates, storage proteins and enzymes) as they relate to food quality and functionality, while defining the environmental impact upon functional properties of biochemical components that affect end-use properties, then applying that information generated to the development and improvement of methods to rapidly predict grain quality.


1b.Approach (from AD-416)
Isolate large quantities of starch, separate into size fractions for baking and chemical testing. Continue testing the correction model for starch size distributions on the LDS. Initiate bake studies using reconstituted gluten and starch fractions. Begin testing, amylose /amylopectin ratios, pasting profiles, DSC temperatures and lipids of A, B, and C-type starch fractions. Complete chemical analysis of the starch fractions. Correlation analysis comparing bake data, starch size distributions and chemical analysis.

Identify wheat of different oxidation requirements and determine effect of oxidative enzymes and transglutaminase upon quality characteristics. Begin biochemical analysis on the effect of enzymes on protein interactions. Characterize enzyme effects on protein interactions between glutenin and albumins. Characterize effect of HMW-GS contribution of wheat on enzyme mediated crosslinking.

Identify and begin to collect wheat samples to represent various growing environments. Begin isolating starch for analysis. Use LDS and our correction model to detect environmental differences in starch ratios. Isolate the starch fractions from different environments for chemical analysis. Compare starch size distributions and chemical analysis to different environments.

Characterize by RP-HPLC and SEC-HPLC, the protein fractions of the various near- isogenic lines that are produced in year 1 study by our collaborators. Relate the period of formation and amount of particular glutenin (polymeric) and gliadin (monomeric) proteins to the HMW-GS in the various near-isogenic lines. Correlate information obtained in this year 1 and 2 study with the data on bread or tortilla quality characteristics, provided by the HWWQL. Characterize the protein fractions of the various near-isogenic lines that were produced by our collaborators. Determine the sizes of the polymeric fractions and the MW distributions of the polymeric proteins. Relate polymer sizes and molecular weight distributions to quality characteristics, provided by the HWWQL. Determine if particular proteins are markers for quality traits.

Develop inexpensive lab-on-a-chip technology to extract and separate wheat gliadins in less than 1 min. Develop lab-on-a-chip system to extract, separate and identify wheat varieties in seconds. Develop a portable lab-on-a-chip system to extract, separate wheat proteins, and identify wheat varieties and/or the quality of wheat varieties or mixtures in seconds.


3.Progress Report
Starch Chemistry: Six varieties of hard red winter wheat from the Kansas Winter Wheat Performance Trials, 2007 and 2008 growing seasons; Jagalene, Danby, Overly, 2174, Endurance and OK Bullet were grown in three locations; dryland growing conditions in Thomas and Harvey County, and irrigated growing conditions in Thomas county. Variety, Endurance, was dropped from the trial in 2008. A fourth county Riley was included in the 2007 growing season but was eliminated from the study due to a late freeze in 2008, eliminating all varieties from the trial.

Single kernel hardness, mixograms, flour particle size, NIR protein and ash have been completed for years 2007 and 2008. Bake data has been completed for 2007 but not for 2008 due to heating and cooling issues in the building for the last 6 months. Starch has been isolated from both years and differential scanning calorimetry, starch granule size analysis as well as starch structure characterization (amylose/amylopectin ratios and amylopectin branch chain length) are in the process of being completed. When the remaining data has been collected statistical correlations to protein content, bake quality data, biochemical and physical starch properties and how they relate to environmental differences will be evaluated.

Research on tortilla quality has continued to investigate the effects of over-expressing individual high molecular weight glutenin subunits (HMW-GS) on important quality parameters. Both elimination and overproduction of certain HMW-GS alter distinct, but critical aspects of tortilla quality such as diameter, shelf stability and overall quality. Experiments were conducted to determine the changes occurring in protein and starch during tortilla making

Lab-on-a-Chip analysis was performed using a selection from 100 hard winter wheat blends developed by GIPSA for a previous collaborative project with GMPRC Grain Quality and Structure and Engineering Research Units. The sample set was chosen due to the thorough physical, chemical and end-use quality data previously generated. As expected, the patterns are complicated and require further analysis to determine statistical correlations to end-use quality parameters. These results will determine the viability of this instrument for commercial samples that exist as mixtures rather than single cultivars.


4.Accomplishments
1. Effects of tortilla processing on protein and starch: Samples were collected at multiple time points during tortilla processing and prepared for protein and starch analysis. Size exclusion HPLC derived from soluble protein fractions revealed protein polymerization as dough was formed. Subsequently, the extractability of soluble proteins (monomeric and soluble polymeric) decreased gradually as dough was transformed into tortillas by hot-pressing and baking. No differences were detected in protein samples isolated from tortillas at days 0, 2 and 7, indicating that changes in protein structure occurred during mixing and baking only. Insoluble proteins were extracted by a reducing agent and chromatograms revealed a gradual increase in total peak area as tortillas were processed. An increase in soluble starch was detected during processing. However, the results revealed a 32% decrease in soluble starch during storage. All together, data presented here indicates that proteins undergo structure changes via formation of larger protein polymers through disulfide cross-links, and starch gelatinizes during baking and retrogrades during storage.


Review Publications
Gajula, H., Liu, S., Alavi, S., Herald, T., Tilley, M., Bean, S., Madl, R. 2009. Pre-cooked Fiber-enriched Wheat Flour Obtained by Extrusion: Rheological and Functional Properties. International Journal of Food Properties. 12:27-44.

Park, S., Wilson, J.D., Seabourn, B.W. 2009. Starch granule size distribution of hard red winter and hard red spring wheat: Its effects on mixing and breadmaking quality. Journal of Cereal Science. 49:98-105.

Huang, W., Yu, S., Zou, Q., Tilley, M. 2008. Effect of frying conditions and yeast fermentation on the acrylamide content in you-tiao, a traditional Chinese fried twisted dough-roll. Food Research International. 41:918-923.

Mondal, S., Hays, D.B., Tilley, M., Alviola, N.J., Waniska, R.D., Bean, S., Glover, K.D. 2009. Functionality of Gliadin Proteins in Wheat Flour Tortillas. Journal of Agricultural and Food Chemistry. 57:1600-1605.

Pierucci, V.R., Tilley, M., Graybosch, R.A., Blechl, A.E., Bean, S., Tilley, K.A. 2009. Effects of Overexpression of High Molecular Weight Glutenen Subunit 1Dy10 on Wheat Tortilla Properties. Journal of Agricultural and Food Chemistry. 57:6318-6326.

Sroan, B.S., Bean, S. and Macritchie, F. 2008. Mechanism of Gas Cell Stabilization in Breadmaking. II. The Primary Gluten-starch matrix. Journal of Cereal Science. 49:41-46.

Last Modified: 8/19/2014
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