KANSAS
KANSAS AGRICULTURAL STATISTICS
Room 200, 632 S.W. Van Buren, Topeka, KS 66603, USA.
E.J. Thiessen, Sherri Hand, and Ron Sitzman.
Overley became the leading cultivar of wheat seeded in Kansas for the 2007 crop. Jagalene held this position last year. Accounting for 23.3 percent of the state's wheat, Overley increased 8 points from a year ago and was the most popular cultivar in four of the nine districts. Jagalene moved down to second place, with 23.1 percent of the acreage. Jagalene decreased 4.1 points but was the most popular cultivar in four of the nine districts. Jagger came in third at 17.1 percent, down 2.6 points. TAM 111 moved up to fourth place, with 4.0 percent of the acreage. The KSU-maintained cultivar 2137 moved down to fifth place with 2.9 percent of the acreage. Cutter moved up to sixth place with 2.1 percent of the acreage. T81 dropped to seventh place at 2.0 percent and TAM 110 moved down to eighth place at 1.5 percent. Santa Fe moved up to ninth place with 1.3 percent of the state's acreage. Ike rounded up the top ten at 1.2 percent. Acres planted with blended cultivars were not included in the rankings by cutivar. Blends accounted for 10.4 percent of the state's planted acres and were used more extentively in the north central, northeast, and central areas of the state. Out of the total acres planted with blends, 62.1 percent included Jagger in the blend, 51.0 had Jagalene in the blend, and 39.6 percent included Overley. Hard white cultivars accounted for 1.7 percent of the state's acreage. Danby was the leading hard white cultivar, accounting for 41 percent of the state's white wheat. The majority of the white wheat was planted in the western third of the state. This Wheat Variety project is funded by the Kansas Wheat Commission.
| Cultivar | % of acreage | Cultivar | % of acreage |
|---|---|---|---|
| 1. Overley | 23.3 | 6. Cutter | 2.1 |
| 2. Jagalene | 23.1 | 7. T81 | 2.0 |
| 3. Jagger | 17.1 | 8. TAM 110 | 1.5 |
| 4. TAM 111 | 4.0 | 9. Sante Fe | 1.3 |
| 5. 2137 | 2.9 | 10. Ike | 1.2 |
KANSAS STATE UNIVERSITY
ENVIRONMENTAL PHYSICS GROUP
Department of Agronomy, Waters Hall, Kansas State University, Manhattan, KS 66506-5501, USA.
M.B. Kirkham
Crops must grow in space, if astronauts are to have food on long flights. However, plant roots need gravity to grow into soil. The response to gravity developed when plants invaded land. This response is believed to be mediated through statoliths (amyloplasts), which are gravisensors in roots and cause them to grow downward. They are capable of swiftly responding when a root is displaced relative to the gravity vector. In space, roots grow in any direction, including upwards. To keep roots in soil, covers are placed on top of pots in space. Despite the primary function of roots in taking up water for plant growth, essentially no information exists in the published literature on the plant-water relations of roots in space. The objective of this study was to determine the effect of gravity on stomatal resistance of wheat. Response of stomata in leaves is closely linked to the roots. Hormones are produced in the roots, which travel to the guard cells, where they either open stomata or close stomata. Hence, one would assume that stomatal resistance might be affected, if roots are grown in space. In this experiment to simulate gravity-free conditions, plants were grown in columns oriented horizontally. Horizontal columns reduce the effect of gravity, because gravity acts only through the diameter-depth of the column.
Two experiments, each with a different depth of planting, were carried out in a growth room. Four columns (each 7 cm in diameter and 40 cm long) were used in each experiment. Two columns were oriented horizontally (placed on their sides) and two columns were oriented vertically (the control columns which had the normal orientation to the earth's surface). The columns were clear so root growth could be observed. In the first experiment, 15 winter wheat (Triticum aestivum subsp. aestivum cultivar Jagger) seeds were planted at the 3-cm depth. In the second experiment, seeds were planted at the 3-mm depth. Stomatal resistance was measured with a leaf porometer (Model SC-1, Decagon Devices, Pullman, WA). Experiments ended when the plants in the horizontal columns were dead or dying, which was two weeks after planting in each experiment.
In the first experiment, plants grown in the horizontal columns germinated but emerged poorly. Four plants emerged out of 15 seeds planted in one horizontal column, and one plant emerged out of 15 seeds planted in the other horizontal column. In the vertical columns, 14 out of the 15 seeds planted in each column germinated and emerged. Average stomatal resistances of the control plants and of the plants that emerged in the horizontal columns were 20 s/cm and >50 s/cm, respectively. In the second experiment, because the seeds were planted near the surface, seeds germinated and emerged from the horizontal columns, as well as the control columns. But, in the horizontal columns, roots did not grow down into the columns and stayed where the seed was planted. Because the roots could not grow down, they used up the water where they were planted and stomatal resistance increased until the plants died. During the second experiment, average stomatal resistances for the control plants and for the plants in the horizontal columns were 28 s/cm and 34 s/cm, respectively. At the end of the experiment, the stomatal resistances of plants grown in horizontal columns were >50 s/cm, as they were in the first experiment. Because the roots could not grow down into the horizontal columns to take up water, the stomata closed, the plants stopped growing, and they died due to lack of water. The results showed that, for stomata to remain open in space, the response to gravity is going to have to be bred out of crop plants like wheat or else undifferentiated, primitive forms of plants, like unicellular algae, may have to be used for food. Alternatively, water and nutrients may have to be supplied by foliar application, negating the need for roots to supply them.
Mr. Prasanna Ayyaru Thevar from India is a Master's degree student who arrived in May, 2006, and is working jointly under M.B. Kirkham and R.M. Aiken.
Mr. Intkhab Hazoor Wahla, a Ph.D. student at the University of Agriculture, Faisalabad, Pakistan, is spending six months (February-August 2007) in the laboratory on a research fellowship sponsored by the Pakistani-USA Ph.D. Partial Support Program of the Higher Education Commission in Islamabad, Pakistan.
THE WHEAT GENETIC AND GENOMIC RESOURCES CENTER – WGGRCDepartment of Plant Pathology, Throckmorton Hall, Kansas State University, Manhattan, KS 66506-5502, USA.
http://www.ksu.edu/wgrc/
B.S. Gill, B. Friebe, W.J. Raupp, D.L. Wilson, T.S. Cox, R.G. Sears, G.L. Brown-Guedira, and A.K. Fritz.
Research from the WGGRC for the last 25 years was summarized for an article in Advances in Agronomy. During this time, over 30,000 samples from the WGGRC collection of wild wheat relatives, cytogenetic stocks, and improved germ plasm have been distributed to scientists in 45 countries and 39 states in the U.S. Karyotypes (chromosome constitution) of 26 wild species and 72 introgression lines with useful agronomic traits have been described. Over 800 new cytogenetic stocks have been developed. These materials are part of the basic tool kit of every wheat geneticist. The WGGRC has released 47 improved germ plasm lines incorporating over 50 new pest-resistance genes that are being exploited in wheat-breeding programs. The K-State cultivar Overley wheat is protected from leaf rust from a gene extracted from a wild wheat strain collected in Iran. The WGGRC hosted over 36 scientists, especially from developing countries, for advanced training. CIMMYT has made extensive use of WGGRC germ plasm, being present in the pedigree of over a quarter of their advanced breeding lines.
V. Kuraparthy, P. Chhuneja, H.S. Dhaliwal, S. Kaur, R.L. Bowden, and B.S. Gill.
Previously, leaf and stripe rust-resistant introgression lines were developed through induced homoeologous chromosome pairing between wheat chromosome 5D and 5Mg of Ae. geniculata. Genomic in situ hybridization with Ae. comosa DNA as a probe showed three different kinds of introgressions. All three types of introgression lines had complete and similar resistance to the most prevalent races of leaf (PRTUS 25, PRTUS 35, PNMQ, MCDL, and PRTUS 6) and stripe rust (03 and 04) in Kansas. One resistant line (TA5602) with a cytologically undetectable introgressed segment was used for molecular characterization of leaf and stripe rust resistance. This line (TA5602), which is agronomically as good as the recipient parent (WL711), was used to transfer the leaf rust and stripe rust resistance to the Kansas winter wheat cultivars Jagger and Overley. The F1 between Jagger and the rust-resistant introgression line (TA5602) was backcrossed further with Jagger and Overley to produce a BC3F1 where the BC3F1 plants are being grown in the greenhouse to isolate homozygous, rust-resistant BC3F2 progenies in the Jagger and Overley background for further agronomic evaluations in the field and subsequent germ plasm release. Diagnostic polymorphisms between the rust-resistant introgression line and the recipient parents were identified using physically mapped RFLP and EST probes. CAPS (cleaved amplified polymorphic sequences) markers are being developed from the diagnostic ESTs, which will be useful for the marker-assisted breeding for rust resistance in wheat.
V. Kuraparthy, S. Sood, P. Chhuneja, H.S. Dhaliwal, S. Kaur, R.L. Bowden, and B.S. Gill.
Working with the scientists at Punjab Agricultural University, Ludhiana, India (Chhuneja, Dhaliwal, and Kaur), we identified one novel, leaf rust-resistant introgression line (TA5604) from progenies that were developed by directly crossing hexaploid wheat with rust-resistant Ae. triuncialis. Bulk segregant analysis was used to identify the chromosome location of the rust-resistant introgression using molecular markers and an F2 population from the cross 'Jagger / TA5604'. Further genetic mapping using SSRs and RFLP markers showed that the leaf rust resistance gene (tentatively designated as LrTri) mapped on the long arm of chromosome 2B. One SSR marker and one RFLP marker diagnostically identified the rust resistance of Ae. triuncialis. The rust resistant line (TA5604), which is agronomically as good as the recipient parent (WL711), was used to transfer the leaf rust resistance to the Kansas winter wheat cultivars Jagger and Overley through a backcross- breeding program. Presently, the BC3F1 plants are being grown to isolate homozygous, rust-resistant BC3F2 progenies in the Jagger and Overley background for further agronomic evaluations in the field and subsequent germ plasm release. CAPS (cleaved amplified polymorphic sequences) markers are being developed from the diagnostic RFLP marker, which will be useful for the marker-assisted breeding for rust resistance in wheat.
V. Kuraparthy, S. Sood, and B.S. Gill.
With the departure of Gina Brown-Guedira, we inherited rust-resistant breeding materials from interspecific crosses. Two lines from this material with leaf and stripe resistance from T. monococcum subsp. monococcum (Trit 2R and Trit 3R) were backcrossed to Overley wheat. We screened 333 progeny from 49 BC2 lines for resistance to leaf and stripe rust. Twelve BC2F2 lines resistant to both leaf and stripe rust will be selfed and their progeny screened for isolation of homozygous resistant lines.
B. Friebe, L.L. Qi, and B.S. Gill.
Previously, we released the germ plasm line WGRC27 with resistance to WSMV controlled by Wsm1, a gene transferred from Th. intermedium to wheat in the form of a wheat–Th. intermedium T4Ai#2S·4DL translocation. Wsm1 confers immunity to the virus, but germ plasm with the T4Ai#2S·4DL translocation suffers from a yield penalty. For several years, we have been trying chromosome engineering to improve the agronomic performance of this germ plasm. Line WGRC27 was crossed with ph1b mutant, and the F1 was backcrossed with ph1b. In the BC1 of the cross T4Ai·4DL/ph1b mutant, we identified 12 plants homozygous for ph1b of which four plants were heterozygous for 4D and the translocation chromosome. At meiotic metaphase I, a ring bivalent between 4D and T4Ai#2S·4DL was observed in one out of 57 pollen mother cells analyzed. In 245 plants of the BC1F2, we identified five recombinants using molecular markers and confirmed them by GISH. Four lines (45, 64, 87, and 213) had recombinant 4D chromosomes with about 80% of the proximal region of the short arm derived from 4DS and the distal 20% of this arm derived from 4Ai#2S. Line 36 had a recombinant chromosome in which about 80% of the short arm was derived from 4Ai#2S and the distal 20% from 4DS. Preliminary greenhouse data suggest that at least the recombinant #213 retains the Wsm1 resistance gene. The recombinants were crossed with the Kansas-adapted wheat cultivar Overley and, after a second backcross with Overley and selfing, we will select homozygous recombinant stocks. In parallel, we selected lines that are homozygous for the recombinant chromosomes, and these lines will be inoculated with WSMV this autumn and the presence of the virus determined by ELISA. The recombinant with the smallest 4Ai#2S segment that still contains the Wsm1 will be made available for cultivar improvement.
A second source of WSMV resistance was mapped to the long arm of an Th. intermedium group-7 chromosome that is available in the form of a ditelosomic 7Ai#2L chromosome addition line. This germ plasm requires further chromosome engineering before it can be used in cultivar improvement and such studies have been initiated.
L.L. Qi, B. Friebe, D.L. Wilson, and B.S. Gill.
Fusarium head blight or wheat head scab can be a significant disease in a year with a wet spring. Working with scientists at Nanjing Agricultural University in China, we have identified a new source of resistance from a perennial grass relative L. racemosis (Lr). A chromosome segment (called Lr#1S) from this grass specifying resistance to FHB has been transferred to a chromosome arm of wheat (7AL) in the form of a translocation T7AL·7Lr#1S. This translocation stock was crossed twice with ph1b, and plants homozygous for ph1b and heterozygous for T7AL·7Lr#1S and 7A will be identified this autumn. In these genotypes, homoeologous recombination can occur between the 7Lr#1S and 7A arms, and putative recombinants will be identified by molecular marker analyses and then confirmed by GISH.
LL Qi, P. Zhang, B. Friebe, and B.S. Gill.
The closely related genomes within hexaploid wheat as well as in the related Triticeae taxa share large, conserved chromosome segments and provide a good model for studying the evolution of pericentromeric regions that are known to be often heterochromatic and among the most rapidly evolving regions of eukaryotic genomes. We initiated a comparative analysis of pericentromeric regions in the Triticeae and confirmed the presence of four pericentric inversions involving chromosomes 2B, 4A, 4B, and 5A in Chinese Spring wheat. In addition, we identified two more pericentric inversions involving chromosomes 3B and 6B of Chinese Spring. Only the 3B inversion pre-existed in chromosomes 3S, 3Sl, and 3Ss of Aegilops species belonging to the section Sitopsis, whereas the remaining inversions occurred after wheat polyploidization. The B genome appears to be more prone to chromosomal rearrangements than are the A and D genomes. Five different pericentric inversions were detected in rye chromosomes 3R and 4R, 4Sl of Ae. longissima, 4H of barley, and 6E of Ag. elongatum. The pericentromeric regions in the Triticeae, especially those of group-4 chromosomes, are undergoing rapid and recurrent rearrangements.
L.L. Qi, B. Friebe, and B.S. Gill.
We recently reviewed the status of chromosome engineering using homoeologous recombination and crop improvement and demonstrated that the integrated use of cytogenetic stocks, molecular marker resources, and molecular cytogenetic techniques can enhance the efficiency of homoeologous recombination based chromosome engineering. In this study, we reported on homoeologous recombination based transfer of virus resistance from and alien chromosome to a wheat chromosome, its characterization, and the prospects for further engineering by a second round of recombination. Previous chromosome engineering has been limited to single chromosomes or chromosome arms. The power of molecular marker analyses now opens the way for a genome wide production of recombinant chromosome stocks. We have proposed a scheme that is based on the fact that homoeologous recombination is limited to one or a few sites in each chromosome arm and that the genes determining most agronomic traits are located in the distal ends of the chromosomes. For each alien chromosome, four recombination events, two per arm, are needed. In addition, a battery of codominant centromeric and telomeric markers are required. We have outlined crossing schemes to obtain plants that are homozygous for ph1b and heterozygous for a set of seven wheat and alien chromosomes. Presently, we are verifying this strategy by producing genome wide recombinant chromosome stocks involving D-genome chromosomes of wheat and V-genome chromosomes of the close relative Haynaldia villosa.
S.A. Brooks, L. Huang, M.N. Herbel, B.S. Gill, G.L. Brown-Guedira, and J.P. Fellers.
It is important to know how genetic variation that we want to tap for crop improvement is organized in natural populations of wild relatives of crop plants. This research produced the surprising result of gene deletion and insertion polymorphism for a defense-gene cluster in a diploid wild wheat species. This paper is adding to the mounting evidence of rapid evolution for genes involved in biotic and abiotic stress response and, thereby, stresses the need for conservation in situ so that evolutionary processes can continue in nature in response to the rapidly changing environment. This work was done in collaboration with John Fellers, USDA-ARS Plant Science Unit, Manhattan, KS.
D.R. See, S.A. Brooks, J.C. Nelson, G.L. Brown-Guedira, B. Friebe, and B.S. Gill.
Although wheat and rice separated from a common ancestor 40 million years ago, they share extensive gene synteny, which means that wheat genes can be discovered using the rice genome template that has been sequenced completely. Five percent of the wheat genes were not found in rice. Wheat-specific genes were located in the distal ends of chromosomes where there is, presumably, a high turnover of genes because of high recombination.
Two students received their Ph.D. degrees recently. Kolluru Vijayalakshmi (dissertation topic 'Genetic characterization of heat tolerance in wheat'), in December 2006 and Vasu Kuraparthy ('Genomic targeting and mapping of agronomically important genes in wheat') in May 2007. Li Huang will join the faculty of the Department of Crop Sciences and Plant Pathology at Montana State University, Bozeman, in September 2007.
U.S. GRAIN MARKETING AND PRODUCTION RESEARCH CENTER
USDA, Agricultural Research Service, Manhattan, KS 66502, USA.
M. Tilley, F.E. Dowell, B.W. Seabourn, J.D. Wilson, S.R. Bean, E.B. Maghirang, O.K. Chung, S.H. Park, T.C. Pearson, F. Xie, T.J. Schober, H. Akdogan, G.L. Lookhart, M.S. Caley, S.Z. Xiao, F.H. Arthur, M.E. Casada, D.B. Bechtel, D.L. Brabec, D.R. Tilley, R.K. Lyne, and R.C. Kaufman.
B. Carver, R. Hunger, A. Klatt, J. Edwards, D.R. Porter, J. Verchot-Lubicz, B. Martin, B.W. Seabourn, and P. Rayas-Duarte.
Deliver (PI 639232) hard red winter wheat was released to certified seed growers with permission of the Oklahoma Agricultural Experiment Station (AES) and the USDA'ARS in 2004. Deliver, an awnletted cultivar, was named for its unique and competitive ability to deliver in grain-only, graze-plus-grain, and forage-plus-hay management systems. The targeted production area extends throughout Oklahoma and the southern Great Plains except in areas limited by soil acidity and aluminum toxicity. Deliver was selected from the single cross 'OK91724 / Karl', in which Karl is a HRWW cultivar developed by the Kansas AES and the USDA-ARS and released in 1988. OK91724 is an unreleased breeding line developed by the Oklahoma AES from the cross 'Yantar / 2*Chisholm'. Deliver is semidwarf and intermediate in plant stature relative to most HRW wheat cultivars. Mature-plant height (85 cm in Oklahoma) is within 2 cm of Jagger, 2174, and Ok101. Based on field observations under natural infection in Oklahoma and cooperative evaluations in the USDA-ARS regional nursery program, Deliver has adult-plant resistance to wheat leaf rust races currently present in Oklahoma. Based on single-kernel characterization system data recorded from 27 breeder trials from 1999 to 2003, Deliver has above-average kernel size and below-average kernel hardness. Dough strength based on the mixograph is slightly superior to Ok101. Overall milling and baking quality was rated acceptable in the 2003 evaluation program of the Wheat Quality Council.
D.B. Bechtel and J.D. Wilson.
Starch is most abundant storage reserve in the wheat caryopsis
yet little is known about its influence on end use properties.
Starch was isolated from wheat grains of different classes and
analyzed using digital image analysis coupled to a light microscope
to determine starch size distributions. The image analysis data
was converted into volume data. Starch granules with diameters
greater than 5 µm were treated as oblate spheroids for calculating
volume using the formula for an oblate spheroid. The measured
equivalent diameter and an estimated starch granule thickness
value were used for the major and minor axes in the oblate spheroid
formula, respectively. Granules less than 5 µm in diameter
were treated as spheres. Starch granules that had their perimeter
touching the edge of field of view had their volumes corrected
using correction formulae. Correction formulae were developed
for each wheat class or starch size distribution class. Correction
formulae were important because without them up to 50 % of the
large type-A granules could be under counted. Data indicated that
there can be a wide variation in the size distribution of starch
depending on wheat class and environmental effects. Some wheats
exhibited a trimodal distribution of starch while others only
exhibited a bimodal distribution. This data will be used to help
predict wheat quality.
S.D. Haley, J.S. Quick, J.J. Johnson, F.B. Peairs, J.A. Stromberger, S.R. Clayshulte, B.L. Clifford, J.B. Rudolf, B.W. Seabourn, O.K. Chung, Y. Jin, and J.A. Kolmer.
Hatcher (Reg. no. CV-971, PI 638512) hard red winter wheat was developed by the Colorado Agricultural Experiment Station and released to seed producers in August 2004. Hatcher was released based on its resistance to the original North American biotype, designated as Biotype 1 (D.R. Porter, personal communication, 2004) of the Russian wheat aphid, and its adaptation to nonirrigated production in eastern Colorado and the west-central Great Plains. Hatcher is susceptible to both WSMV and BYDV, heterogeneous for resistance to the Great Plains biotype of Hessian fly , and susceptible to greenbug. Resistance to Russian wheat aphid Biotype 1 in Hatcher is conditioned by the Dn4 resistance gene. Russian wheat aphid resistance scores for Hatcher in standard greenhouse seedling screening tests using Biotype 1 are similar to other cultivars that carry Dn4. Values for milling-related variables were generally superior to those of both Ankor and Prowers 99. Hatcher had a higher Quadromat Senior flour extraction (685 g/kg sup) than those of Ankor (658 g/kg sup) and Prowers 99 (4.8 g/kg sup). Values for baking-related variables of Hatcher were generally intermediate between Ankor and Prowers 99. Hatcher (120 g/kg sup) had a similar grain protein content as that of Ankor (120 g/kg sup) and lower than that of Prowers 99 (138 g/kg sup). In mixograph tests optimized for water absorption, Hatcher had higer water absorption (618 g/kg sup) than that of Ankor (615 g/kg sup) and lower than that of Prowers 99 (649 g/kg sup); a higher tolerance score (3.2; 0 = unacceptable to 6 = excellent) than that of Ankor (2.2 score) and lower than that of Prowers 99 (4.0); and longer mixing time (3.2 min) than that of Ankor (2.9 min) and shorter than that of Prowers 99 (4.0 min). In straight-grad pup loaf baking tests, Hatcher had lower bake water absorption (600 g/kg sup) than those of Ankor (605 g/kg sup) and Prowers 99 (633 g/kg sup); a longer bake mixing time (4.2 min) than that of Ankor (3.6 min) and shorter than that of Prowers 99 (5.1 min); a smaller pup loaf volume (0.872 L) than those of Ankor (0.888 L) and Prowers 99 (0.945 L); and a lower loaf crumb grain score (3.8; 0 = unacceptable to 6 = excellent) than Ankor (4.0) and Prowers 99 (4.5).
F.E. Dowell, E.B. Maghirang, F. Xie, G.L. Lookhart, R. Pierce, B.W. Seabourn, S. R. Bean, J.D. Wilson, and O.K. Chung.
The accuracy of using near-infrared spectroscopy (NIRS) for predicting 190 grain, milling, flour, dough, and breadmaking quality parameters of 100 HRWW and 98 HRSW and flour samples was evaluated. NIRS shows the potential for predicting protein content, moisture content, and flour color b* values with accuracies suitable for process control (R2 > 0.97). Many other parameters were predicted with accuracies suitable for rough screening including test weight, single-kernel diameter and moisture content, SDS sedimentation volume, color a* values, total gluten content, mixograph, farinograph, and alveograph parameters, loaf volume, specific loaf volume, baking water absorption and mix time, gliadin and glutenin content, flour particle size, and dark hard and vitreous kernels. Similar results were seen for HRWW and HRSW, and when predicting quality using spectra from grain or flour. However, many attributes were correlated to protein content. When the influence of protein content was removed from the analyses, the only factors that could be predicted by NIRS with R2 > 0.70 were moisture content, flour color, and dark hard and vitreous kernels. Thus, NIRS can be used to predict many grain quality and functionality traits, but mainly because of the high correlations of these traits to protein content.
T.C. Pearson and D.L. Brabec.
Grain kernels infested by insects may show no indication on their exterior, but often contain hidden larvae.
Although grain is always inspected for insect infestations upon shipping and receiving, many infested samples go undetected.
Many methods for detecting infested wheat have been developed but none has seen widespread use due to expense
or inadequate accuracy, or both. In this study, a laboratory roller mill system was modified to measure and analyze
the electrical conductance of wheat as it was crushed. This facilitated detection of wheat kernels with live insects
hidden inside of them. Furthermore, the apparatus is low cost (~$1,500 for parts) and can inspect a 1-kg sample in less than
two minutes.
T.J. Schober and S.R. Bean.
Capillary zone electrophoresis (CZE) in acidic buffer systems is capable of separating cereal storage proteins based on similar separation principles as classical acidic polyacrylamide gel electrophoresis. However, it is faster, its resolution is distinctly higher and data evaluation is much simpler. Applying a 100 mM sodium phosphate buffer system, pH 2.5, containing hydroxypropyl methylcellulose (HPMC), and using a 60-cm capillary, CZE was successfully used in a spelt breeding program. Several examples are given: mislabeled samples could be identified, although the differences in the patterns were very small. Relatedness between different spelt cultivars could be shown. However, it was not possible to clearly differentiate between pure spelts and wheat-spelt crosses. Crossing spelt with modern wheat may be, but is not necessarily, reflected in the gliadin pattern. This latter finding is in agreement with several studies, showing that one single protein class (LMW-glutenin subunits, gliadins) did not always reflect purity of spelt. The acidic phosphate buffer system was compared to an isoelectric buffer system composed of 50 mM iminodiacetic acid (IDA), HPMC and acetonitrile, using a short (27 cm) capillary. We found that the IDA system provided more than 10 times faster separations with almost the same resolution as the sodium phosphate system. We concluded that CZE, especially with the IDA buffer, is a fast and powerful tool in spelt breeding programs to avoid mislabeling, and gain insight into the relatedness of new lines with unknown pedigrees.
J.D. Wilson, D.B. Bechtel, G.W.T. Wilson, and P.A. Seib.
Flours from five spelt cultivars grown over 3 years were evaluated as to their bread baking quality and isolated starch properties. The starch properties included amylose contents, gelatinization temperatures (differential scanning calorimetry), granule size distributions and pasting properties. Milled flour showed highly variable protein content and was higher than hard winter wheat, with short dough-mix times indicating weak gluten. High protein cultivars gave good crumb scores, some of which surpassed the HRWW baking control. Loaf volume was correlated to protein and all spelt varieties were at least 1015% lower than the HRWW control. Isolated starch properties revealed an increase in amylose in the spelt starches of between 47% over the HRWW control. Negative correlations were observed for the large A-type granules to bread crumb score, amylose level, and final pasting viscosity for cultivars grown in year 1999 and to pasting temperature for samples grown in 1998. Positive correlations were found for the small B- and C-type granules relative to crumb score, loaf volume, amylose, and RVA final pasting viscosity for cultivars grown in year 1999, and to RVA pasting temperature in 1998. The environmental impact on spelt properties seemed to have a greater effect than genetic control.
J.D. Wilson, R.C. Kaufman, and S.H. Park.
Starch constitutes the greatest weight portion of the wheat endosperm (6575%) and contributes its own unique
functional qualities such as texture, volume, consistency, aesthetics, moisture, and shelf stability to various baked products.
Particle size has long been recognized as an important variable in the efficiency of a range of processes
including predicting rheology and flow behavior. Although genetics is the dominant determinant in caryopsis development
the environment also has a critical role in quality variability. Our objective was to study starch size distribution in
identical varieties of developing HRWW grown in the same location over at least five consecutive years and correlate
differences to various environmental factors. The samples were collected from the Kansas State University Agronomy field plots
in Manhattan, KS. The heads were tagged as to flowering dates and samples were collected starting at 7
days-after-flowering (DAF) and regularly sampled until harvest. The starch was isolated, then freeze-dried and starch size
distribution was analyzed on a laser diffraction particle size analyzer. Trends were observed within varieties between starch
size distribution and temperature as well as total precipitation in 10, 17, and 28 DAF and just prior to harvest. These
trends included total volume fluctuations and shifts in peak diameters of 10-20% of the A-type granules. Studying starch
size distribution during development of the wheat caryopsis may provide needed insight into critical environmental
growth phases.
F.E. Dowell, E. B. Maghirang, F. Xie, G.L. Lookhart, R. Pierce, B.W. Seabourn, S. Bean, J. Wilson, and O.K. Chung.
Rapid tests are needed by the wheat industry to measure grain quality to determine value, and to predict the bread
quality that will be produced from that grain. Near-infrared spectroscopy commonly is used to measure characteristics such
as
protein and moisture content, and may have potential for measuring other parameters. This rapid technology
was examined from measuring 190 grain, milling, flour, dough, and bread-making quality parameters of 100 HRWW and
98 HRSW samples. Protein content, moisture content, and flour color were predicted with very high accuracies.
Other parameters that showed some potential for rough screening using NIRS include test weight, dark hard and
vitreous kernels, SDS sedimentation volume, gluten content, gliadin and glutenin content, water absorption, and loaf volume.
However, many of these characteristics are highly correlated to protein content. When the influence of protein
content was removed, the only factors that could be predicted by NIRS were moisture content, flour color, and dark hard
and vitreous kernels. Similar results were seen for hard red winter and spring wheat, and when using spectra from grain
or flour. This study emphasizes the advantages and limitations of NIR technology, and the need for developing other
rapid quality prediction tests.
B.W. Seabourn, F. Xie, and O.K. Chung.
The traditional method in the U.S. for screening hard winter wheat breeding lines is based upon the optimum
mixing time (MT), an important rheological property of a wheat flour-water (dough) system typically obtained from the
mixograph. This method is time-consuming and requires some degree of subjective interpretation, especially with regard
to mixing tolerance. The purpose of this study was to investigate the potential of FTHATR spectroscopy to
objectively predict optimum MT in doughs from a short-duration mixing cycle (1 min). Hard winter wheat flours with
varying protein content and MT were scanned in the amide III region of the mid-infrared by FTHATR immediately after
being mixed 1 min with a mixograph. The ratio of the band areas at 1,336/cm
(alpha-helix) and 1,242/cm (beta-sheet) was highly correlated to optimum MT as determined by the mixograph
(R2 = 0.81). Results from this study indicate that
optimum MT could be predicted early in the mixing process based upon changes in the secondary structure of the dough protein.
This method could provide the basis for new technology to rapidly and accurately screen wheat samples in early
generation breeding lines, thus saving considerable time and expense in the development of new cultivars.
B.W. Seabourn, F. Xie, and P.A. Seib.
The relatively recent advent of FTHATR mid-infrared spectroscopy has provided a unique and simple tool for
evaluating gluten protein secondary structures in dough. In a previous study we reported that dough optimum mixing time
(MT) was closely related to gluten protein secondary structures that developed early in the mixing cycle. To more
fully understand the role of gluten secondary structure in dough rheology, further investigation into the relationship
between wheat gluten secondary structure and wheat end-use properties was carried out. A total of 55 hard red winter
wheat flours with varying protein contents (8.714.2%) and MT (1.637.38 min) were scanned with three replicates for
each sample by FTHATR (4,000700/cm) immediately after being mixed with a mixograph (MIXO) for 1 min. A total of
34 end-use properties of each sample were evaluated including milling, baking, noodle making, PPO, RVA, SKCS,
Mixograph, and other analytical tests. The second derivative band areas at 1,339/cm
(alpha-helix), 1,285/cm (beta-turn), 1,265/cm (random coil), and 1,242/cm
(beta-sheet) were highly correlated to MIXO MT, MIXO tolerance, baking MT, and
LV potential. The band area at 1,242/cm (b-sheet) and MIXO tolerance had the highest correlation coefficient (r)
0.89. Crumb grain was negatively related to
b-sheet and b-turn structures at 1,242/cm and 1,285/cm with r value
0.61, respectively. Multiple regression results showed that approximately 73%, 81%, and 70% of the total variance in
MIXO MT, MIXO tolerance, and bake MT could be explained by the relationship between gluten secondary structures and
these parameters, respectively.
Z.S. Xiao, S.H. Park, M.S. Caley, R.K. Lyne, M. Tilley, B.W. Seabourn, and O.K. Chung.
The 5% lactic acid solvent retention capacity (SRC) test and SDS-sedimentation test were investigated to find
their relationships to loaf volumes (LV) of HWW and HSW flour. A total of 196 flours, 98 HWW and 98 HSW with
protein ranges of 8.214.2% and 10.417.8%, respectively, were used. The 5% lactic acid SRC value was a good indicator
for LV, showing high correlations for both HWW and HSW flours (r = 0.84, respectively, P < 0.0001). On the other
hand, SDS-sedimentation volume was highly correlated only with LV of HWW flours (r = 0.76, P <0.0001), but not
with HSW flour (r = 0.47, P < 0.0001). Even though this r value is statically significant, the r value is lower than that
obtained by 5% lactic acid SRC test. In addition, the 196 samples were divided into low and high protein groups
(8.213%, n = 135 and 13.117.8%, n = 61, respectively) to find how those two tests correlated to the LV of each group.
We found that both 5% lactic acid SRC and SDS sedimentation tests showed strong correlations with the LV of the
low protein group (r = 0.83 and 0.78, respectively), whereas with the high protein group, only 5% lactic acid SRC
test showed a high correlation (r = 0.81) and SDS-sedimentation test showed a lower correlation (r = 0.38, P < 0.01).
Similar results were obtained when each HWW and HSW flours were divided into low and high protein groups. Wheat class
had little influence on the 5% lactic acid SRC test results, whereas protein content did. The results demonstrate that
5% lactic acid SRC test is a more robust test to predict the LV of both classes of wheat flours over a broad range of
protein content.
S.Z. Xiao, S.H. Park, O.K. Chung, and M.S. Caley.
Solvent retention capacity was investigated in assessing the end-use quality of HWW. The four SRC values of
116 HWW flours were determined using 5% lactic acid, 50% sucrose, 5% sodium carbonate, and distilled water. The
SRC values were greatly affected by wheat and flour protein contents, and showed significant linear correlations with
1,000-kernel weight and single kernel weight, size, and hardness. The 5% lactic acid SRC value showed the highest
correlation (r = 0.83, P < 0.0001) with straight-dough bread volume, followed by 50% sucrose, and least by distilled water.
We found that the 5% lactic acid SRC value differentiated the quality of protein relating to loaf volume. When we selected
a set of flours that had a narrow range of protein content between 1213% (n = 37) from the 116 flours, flour
protein content was not significantly correlated with loaf volume. The 5% lactic acid SRC value, however, showed a
significant correlation (r = 0.84, P < 0.0001) with loaf volume. The 5% lactic acid SRC value was significantly correlated
with SDS-sedimentation volume (r = 0.83, P < 0.0001). The SDS-sedimentation test showed a similar capability to 5%
lactic acid SRC, correlating significantly with loaf volume for flours with similar protein content (r = 0.72, P < 0.0001).
Prediction models for loaf volume were derived from a series of wheat and flour quality parameters. The inclusion
of 5% lactic acid SRC values in the prediction model improved
R2 of 0.778 and root mean square error (RMSE) of
57.2 from R2 of 0.609 and RMSE of 75.6, respectively, from the prediction model developed with Single Kernel
Characterization System and near-infrared reflectance spectroscopy data. The prediction models were tested with three
validation sets having different protein ranges, and confirmed that 5% lactic acid SRC test is valuable in predicting the loaf
volume of bread from a HWW flour, especially for flours with similar protein contents.
H. Akdogan, M. Tilley, S.R. Bean, and R.A. Graybosch.
The mixing parameters and polymeric proteins (PP) of two different wheat cultivars, Centurk (CK) and OK102, each with four lines differing in HMW-glutenin subunit composition were analyzed using multivariate statistical analysis of mixograph parameters. Stepwise discriminant analysis was used to identify significant mixing parameters at P < 0.0001 level. The selected variables, mixing tolerance, peak mixing time, and peak height (torque), were subjected to Principle Component Analysis. The score plots of the first two principal components (PC 1 and PC 2) indicated a clustering in samples: CK with 7+8 and 7+9 at the Glu-B1 and 5+10 at the Glu-D1 loci; CK with 7+8 and 7+9 at the Glu-B1 and 2+12 at the Glu-D1 loci; OK102 with 6+8 and 7+9 at the Glu-B1 and 5+10 at the Glu-D1 loci; OK102 with 6+8 and 7+9 at the Glu-B1 and 3+12 at the Glu-D1 loci. Samples from different cultivars (CK and OK102) were successfully grouped using the same score plots. Polymeric proteins consistently correlated well with mixing tolerance and peak mix time. Insoluble polymeric proteins (IPP) showed a positive relationship with mixing tolerance and peak time, soluble polymeric proteins (SPP) showed a negative correlation with the same parameters. Overall, SPP was a better identifier in terms of grouping Glu-D1 subunits and contributed to higher correlation coefficients than IPP. This method could be beneficial in developing analysis tools in early selection of lines for quality traits in wheat breeding programs.
M. Abu-Ghoush, T. Herald, F.E. Dowell, F. Xie, F.M. Aramouni, and R. Madl.
Flat bread is the oldest and most popular bread in the world. However, in the Middle East where much of this bread
is consumed, many people do not have refrigeration or frozen storage to keep bread fresh and free from mold for more
than a few days. In order to extend bread shelf-life, this study evaluated fumaric acid and sodium propionate separately
and in combination as mold growth inhibitors. Bread quality was measured by the bread tearing time and tearing
strength, and by NIRS. The combination of the two inhibitors inhibited mold growth by 320% when compared to the control.
NIRS was shown to be a rapid means of monitoring bread quality. These results will help reduce the estimated
one billion dollars lost each year due to bread spoilage and staling.
M. Abu-Ghoush, T. Herald, F.E. Dowell, F. Xie, F.M. Aramouni, and C. Walker.
Middle Eastern Countries are experiencing the emergence of Arabic flat bread high volume production and
retail marketing over traditional unit baking and retailing. However, shelf life needs to be increased and bread quality
improved to limit economic loss. We examined five improvers for improving shelf-life and bread quality, and the use
of near-infrared spectroscopy to evaluate bread quality. The improver treatments included sodium 9
stearoyl-2-lactylate, monoglycerides, hydroxyl propyl methyl cellulose gum, high fructose corn syrup, and a combination of all the
aforementioned improvers. The high fructose corn syrup and the improver combination caused the bread to exhibit a
significantly longer tearing time to rupture than the other treatments at day zero. The sensory evaluation showed that the
improver combination significantly improved the quality attributes. The spectroscopic analysis indicated that after 3 days,
the control was less fresh than bread formulated with high fructose corn syrup or improver combinations.
M. Tilley, H.P. Akdogan, and O.K. Chung.
Once predominantly limited to Mexico and the Southwestern U.S., tortillas have become the most prevalent ethnic bread in the U.S., often replacing white pan bread in many products. As a result, tortillas are the fastest growing segment of the U.S. baking industry with annual sales over $6 billion USD and growth exceeding 10%/year. The majority of tortillas consumed in the U.S. are made from wheat flour, although traditional maize tortillas are also produced. Sustaining this tremendous demand requires sufficient definition and determination of fundamental quality characteristics of wheat flour tortillas. Quality characteristics include visual and textural properties as well as shelf-life. Good quality tortillas should remain flexible without cracking and breaking when folded. One of the major challenges in tortilla quality is the deterioration of texture with time (staling). In instances where tortillas are freshly prepared and consumed, shelf life is not an issue, however, in the U.S. retention of fresh properties is important since tortillas are packaged sealed in plastic bags and consumed over the course of several weeks. Tortilla quality is measured using both objective and ubjective methods and is dependent upon flour properties as well as ingredient formulation. Tortilla quality parameters and current evaluation methods are discussed.
H.P. Akdogan, O.K. Chung, H. Singh, and G.L. Lookhart.
The tortilla industry is the fastest growing segment of the baking industry. In the U.S., annual sales of tortillas exceed all other ethnic and specialty bread sales. Consumers' assessment of tortilla quality is highly linked to its texture. The purpose of this study was to evaluate the shelf-life of commercial wheat flour tortillas through their textural parameters. Three types of tortillas (regular, 98% fat-free, and whole wheat) of two different commercial brands (Brand A and Brand B) were studied. All samples were subjected to extensibility and stress relaxation tests by using a TA-XT2 Texture Analyzer at days 0, 2, 6, 9, 12, 15, 19, 23, and 33 of storage. One-way analysis of variance (ANOVA) was used to analyze the data. Fisher's least significant difference (LSD) at 0.05 were used to identify the significant differences in the means of measured and calculated textural parameters. The gradient (modulus of deformation) and work (area under the curve up to maximum force to tear) were not indicative of the textural changes of the studied tortillas. The calculated parameters from the stress relaxation (SR) curve, k1, k2, and % SR, and the distance to tear from the extensibility measurements were able to identify either the first days of storage (day 0 and/or 2) or the last days of storage (day 23 and/or 33). The significant changes came shortly after opening their packages for both brands of regular tortillas. Detectable changes for 98% fat-free tortillas of Brand A and B came after 23 and 2 days of storage, respectively. For whole wheat tortillas most results were not conclusive. The calculated textural parameters, k1, k2, % SR , and distance to tear, identified the significant differences among days of storage. Further research on tortilla formulation and ingredient functionality may provide a better understanding on tortilla staling.
H.P. Akdogan, M. Tilley, and O.K. Chung.
All three emulsifiers tested (SSL, GMS, and de-oiled lecithin) impacted the textural quality of 100% WW tortillas during storage. However, the amount of emulsifier incorporated into the formulation was crucial. SSL was more effective at its lowest usage level (0.125%), unlike the de-oiled lecithin, which was most effective at its highest usage level (2%). The diameters of tortillas with mid (0.25%) and high (0.50%) levels of added SSL were significantly smaller than the rest of the tortillas. Rollability scores and Fr of tortillas were improved with emulsifier addition. Control tortillas consistently resulted in higher Fr values as well as lowest rollability scores at the end of full storage. None of the emulsifiers studied enhanced the stretchability of tortillas, as it abruptly declined during the first two days of storage. Type and level of emulsifier addition to tortillas should be determined carefully as it influences textural properties besides shelf life.
M. Tilley, V. Pierucci, K.A. Tilley, and O.K. Chung.
The suitability of Kansas HWWW milled at a high extraction rate for tortilla production was investigated.
Tortillas were made from eight wheat cultivars milled at 80% extraction: four HWWW cultivars included Betty, Heyne,
Oro Blanco, and NuWest; three HRWW samples were Jagger and Ike grown at Hutchinson, Kansas (Ike-Hutch) and at
Hays, Kansas (Ike-Hays); and one HWSW cultivar, Idaho 377-S. Tortillas made from these flours were compared to
tortillas made from one commercial tortilla flour milled to 72% extraction from a blend of HRW wheat. Mixograph
parameters, starch pasting properties, dough-handling characteristics and tortilla-making attributes of the Kansas HWWW
cultivars, Betty and Heyne, were superior. All of the Kansas HWWW flours, milled to 80% extraction, produced tortillas
which were equal to, or superior to, those made from 80%- extraction HRWW flours and 72%-extraction commercial
tortilla flour.
S.H. Park, O.K. Chung, and P.A. Seib.
Samples of 12 HWW and their flours that produced breads varying in crumb grain scores were studied for 38 quality parameters including wheat physical and chemical characteristics; flour ash and protein contents, starch damage, swelling power, pasting characteristics, and flour particle size distribution; dough properties determined by a mixograph; and bread-making properties for pup loaves. Only two parameters, the protein content of wheat and the granulation of flour, showed significant correlations with crumb grain scores. Protein content of wheat ranging from 12.914.5% determined by an NIR method showed a weak inverse relationship (r = 0.61, P < 0.05) with bread crumb grain score. Flour particle size distribution measured by both Alpine Air Jet Sieve and NIR methods revealed that the weight (wt) % of particles less than 38 µm in size and representing 9.619.3% of the flour weights was correlated positively (r = 0.78, P < 0.01) with crumb grain score, whereas wt % of flour particles larger than 125 µm had an inverse relationship (r = -0.60, P < 0.05) with crumb grain score.
M. Tilley, V. Pierucci, and K.A. Tilley.
The water-soluble extract from wheat flour was fractionated using preparative isoelectric focusing and the fractions were tested for the ability to synthesize dityrosine from tyrosine in vitro. The fraction that catalyzed dityrosine also possessed a high level of peroxidase activity. The major protein was purified and the N-terminal amino acid sequence was determined. The sequence was similar to barley endosperm peroxidase BP1. An oligonucleotide probe based on this sequence was used to screen cDNA libraries from developing kernels of wheat and the progenitor Ae. tauschii. Resulting cDNAs were identical at the amino acid level and had a high similarity to BP1. These findings support data on the nature of endogenous wheat peroxidase and the potential of peroxidase to catalyze dityrosine formation in dough.
T.C. Pearson, J.D. Wilson, J. Gwirtz, E.B. Maghirang, F.E. Dowell, P. McCluskey, and S. Bean.
Grain inspectors have observed that in the U.S. Pacific Northwest region, discriminating soft white wheat from hard white wheat has become increasingly difficult. This poses problems for assigning a proper grade to wheat loads being exported to international customers. Additionally, wheat loads with mixed hard white and soft white wheat may have different baking qualities, and their presence reduces the desirability of U.S.-grown wheat, especially for international customers. The primary instrument for distinguishing hard and soft classes of wheat is called the Single Kernel Characterization System. This research found that, through simple data processing software changes to the SKCS, classification errors between hard white and soft white wheat can be reduced by about 50% over the current configuration of the SKCS. This should help those who use the SKCS to determine wheat class purity, such as wheat inspectors. Also, this should help wheat millers and international customers better understand the quality and properties of incoming wheat loads.
S.H. Park, S.R. Bean, O.K. Chung, and P.A. Seib.
Protein and protein fractions were measured in 49 hard winter wheat flours to investigate their relationship to
bread-making properties, particularly loaf volume which varied from 760 to
1,055cm3/100 g flour, and crumb grain score
of
1.05.0. Total soluble protein (SP) in 50% 1-propanol was separated into albumins and globulins (AG), gliadins,
and soluble polymeric proteins (SPP) using size exclusion high-performance liquid chromatography (SE-HPLC).
Insoluble polymeric protein (IPP) was determined by combustion assay of the residue. Protein composition varied with
flour protein content because SP and gliadin levels increased proportionally to increased protein content, but AG, SPP, and
IPP levels did not. Flour protein content was positively correlated with loaf volume and bake water absorption (r = 0.80, P
< 0.0001 and r = 0.45, P < 0.01, respectively). The percent SP based on flour showed the highest correlation with
loaf volume (r = 0.85) and low but significant correlation with crumb grain core (r = 0.35, P = 0.05). Percent gliadins
based on flour and on protein content were positively correlated to loaf volume (r = 0.73, P < 0.0001 and r = 0.46, P <
0.001, respectively). The percent IPP based on flour was the only protein fraction that was highly correlated (r = 0.62, P
< 0.0001) with bake water absorption followed by AG in flour (r = 0.30, P < 0.05). Bake mix time was correlated
positively with percent IPP based on protein (r = 0.86) but negatively with percent SPP based on protein (r = 0.56, P
< 0.0001).
E.B. Maghirang, G.L. Lookhart, S. Bean, R.O. Pierce, F. Xie, M.S. Caley, J.D. Wilson, B.W. Seabourn, O.K. Chung, and F.E. Dowell.
Various whole-kernel, milling, flour, dough, and bread-making quality parameters were compared between HRWW and HRSW. From the 43 quality parameters evaluated, only eight quality characteristics, test weight, moisture content, kernel size, polyphenol oxidase content, average gluten index, % insoluble polymeric protein, loaf volume adjusted for protein content, and mixograph tolerance, were found to be the same. Some of the quality characteristics that had significantly higher levels in HRSW than in HRWW samples included protein content, flour yield, bread crumb grain score, and other proteindependent parameters such as sodium dodecyl sulfate sedimentation volume, average total gluten, baking water absorption, and loaf volume. When HRWW and HRSW samples were grouped to be within the same wheat protein content range (11.4 to 15.8%), the average value of most other grain and bread-making quality characteristics were the same for both wheat classes. Values that were significantly higher for HRW wheat were color b* and farinograph tolerance. Values that were higher for HRS wheat were mg insoluble polymeric proteins, mg gliadins, mixograph time, alveograph configuration ratio, and crumb score. Test of homogeneity of intercepts showed HRS wheat had higher water absorption, loaf volume, and SDS sedimentation volume.
H. Gajula, S. Liu, S. Alavi, T. Herald, and S.R. Bean.
Cereal products with high fiber can reduce calorie uptake and provide health benefits linked to chronic disease. However, high fiber content tends to diminish the final product quality and consumer acceptability of cereal products such as baked goods and pasta. Our overall objective is to produce high-fiber, precooked flour using extrusion in order to increase functional properties. Our specific objective of this study was to compare rheological and functional properties of extrusion processed wheat precooked whole wheat flour obtained by oven drying and freeze drying. Precooked flours were produced using lab-scale, twin-screw, co-rotating extruder configuring for low shear, low temperature. Swelling and pasting properties of the precooked flours was characterized using rapid visco-analyser standard methodology. Rheological properties were characterized using mixograph standard methodology. The quality of cookies and tortillas were also characterized by AACC Approved Methods.
The results showed that precooked flour using freezer dryer had a similar swelling and pasting properties with oven dried flour. Water absorption increased in the precooked flours as compared to the commercial available flours. The drying methods had no significant effect on the quality of the cookies using precooked flour and commercial available wheat flours. The diameters of cookies using these flours were 9.3 cm, 9.8 cm, and 10 cm with similar spread factor (118.70, 107.09, and 129.35, respectively). The weight, diameter, height, and specific volume of tortilla using oven dried, freeze dried precooked flour, and controlled wheat flour were 22.34 g, 11.33 cm, 0.20 cm, and 0.947 cm3/g; 22.65 g, 11.39 cm, 0.215 cm, and 0.964 cm3/g; and 22.69 g, 12.21 cm, 0.18 cm, and 0.952 cm3/g, respectively. The results suggest that extrusion technology can produce precooked wheat flour with same functionality for baked products, and precooked flour obtained by oven-drying have similar rheological and functional properties as freeze dried flour.
D.R. Tilley, M.R. Langemeier, M. Casada, and F.H. Arthur.
Our previous research has shown that heat treatments are effective as a non-chemical method for disinfestation of empty grain storage bins. We developed an empirical economic risk model to compare variable costs for five tested heating systems for disinfestation of empty, 5,000-bu grain storage bins with fitted drying floors. The high-output, 29 kW, propane heating system had the lowest cost and risk level of all heating systems and achieved the target temperature of 50 C within 2 hours at all test locations. Lower power systems requiring complex heat distribution or recirculation were not cost effective and exhibited higher risk levels of insect survival. These results indicate that properly-sized portable propane heat treatment systems are equal to chemical applications for low-cost, low-risk disinfestation of empty bins, but without the concerns that arise with using chemicals.