KANSAS
KANSAS AGRICULTURAL STATISTICS
Room 200, 632 S.W. Van Buren, Topeka, KS 66603, USA.
E.J. Thiessen, Sherri Hand, and Ron Sitzman.
Jagalene became the leading cultivar of wheat seeded in Kansas for the 2006 crop. Jagger had held this position since 1998. Accounting for 27.2 percent of the state's wheat, Jagalene increased 6 points from a year ago and was the most popular cultivar in five of the nine districts (Table 1). Jagger moved down to second place, with 19.7 percent of the acreage. Jagger decreased 8.5 points but ranked in the tip five in eight of the nine districts. Overley came in third with the biggest increase from last year, up 13.1 points. The KSU-maintained cultivar 2137 moved down to fourth place, with 3.1 percent of the acreage. Back to the top ten is T81, after being out last year, ranking fifth with 2.6 percent. TAM 111, new to the top ten, tied for sixth place with TAM 110 at 2.2 percent. Cutter moved up to eights place with 1.6 percent of the acreage. The OSU-maintained cultivar 2174 moved down to ninth place with 1.2 percent of the state's acreage. Tied for tenth are Ike, Thunderbolt, Karl, and Karl 92, all with 1.1 percent. Acres planted with blended cultivars were not included in the rankings by cultivar. Blends accounted for 10.0 percent of the state's planted acres and were used more extensively in the north central, northeast, and central areas of the state. Out of the total acres planted with blends, 61.3 percent included Jagger in the blend, 46.3 percent had 2137 in the blend, and 42.2 included Jagalene. Hard white cultivars accounted for 36 percent of the state's white wheat. The majority of the white wheat was planted in the western third of the state. This wheat cultivar project is funded by the Kansas Wheat Commission.
| Cultivar | % of acreage | Cultivar | % of acreage |
|---|---|---|---|
| 1. Jagalene | 27.2 | 6/7. TAM 111, TAM 110 | 2.2 |
| 2. Jagger | 17.7 | 8. Cutter | 1.6 |
| 3. Overley | 15.3 | 9. 2145 | 1.2 |
| 4. 2137 | 3.1 | 10. Karl/Karl 92, Ike, Thunderbolt | 1.1 |
| 5. T81 | 2.6 |
| Variety | % of acreage | Variety | % of acreage | Variety | % of acreage |
|---|---|---|---|---|---|
| District 10 (Northwest) | District 40 (North central) | District 70 (Northeast) | |||
| Jagalene | 34.6 | Jagalene | 18.0 | 2137 | 18.3 |
| Jagger | 21.0 | Jagger | 16.9 | 2145 | 14.6 |
| TAM 111 | 5.6 | Overley | 9.9 | Jagalene | 12.3 |
| Thunderbolt | 5.2 | 2137 | 7.2 | Overley | 7.5 |
| NuHills-HWWW | 2.8 | Karl/Karl 92 | 5.9 | Karl/Karl 92 | 7.1 |
| District 20 (West central) | District 50 (Central) | District 80 (East central) | |||
| Jagalene | 32.6 | Jagalene | 24.8 | Jagger | 19.8 |
| Jagger | 15.6 | Jagger | 22.6 | Overley | 18.9 |
| T81 | 9.8 | Overley | 22.0 | 2137 | 15.1 |
| TAM 110 | 6.4 | 2137 | 4.9 | Jagalene | 10.5 |
| TAM 111 | 5.3 | Cutter | 2.9 | Dominator | 5.1 |
| District 30 (Southwest) | District 60 (South central) | District 90 (Southeast) | |||
| Jagalene | 35.1 | Overley | 29.6 | Overley | 23.8 |
| Jagger | 18.0 | Jagalene | 24.5 | Jagger | 16.7 |
| TAM 110 | 9.9 | Jagger | 21.3 | 2137 | 13.5 |
| T81 | 8.6 | 2174 | 2.9 | 2174 | 10.2 |
| TAM 111 | 6.2 | Cutter | 1.9 | Jagalene | 9.9 |
Publications.
Monthly Crop. Wheat cultivars, percent of acreage devoted to each
cultivar. Wheat quality, test weight, moisture, and protein content
of current harvest. $10.00
Crop-Weather. Issued each Monday, March 1 through November 30 and monthly, December through February. Provides crop and weather information for previous week. $12.00
County Estimates. County data on wheat acreage seeded and harvested, yield, and production on summer fallow, irrigated, and continuous cropped land. December.
Wheat Quality. County data on protein, test weight, moisture, grade, and dockage. Includes milling and baking tests, by cultivar, from a probability sample of Kansas wheat. September.
Each of the above reports is available on the Internet at the
following address: http://www.nass.usda.gov/ks/
KANSAS STATE UNIVERSITY
ENVIRONMENTAL PHYSICS GROUP
Department of Agronomy, Waters Hall, Kansas State University, Manhattan, KS 66506-5501, USA.
Stanley Liphadzi and M.B. Kirkham
In 2003 we reported the concentrations of heavy metals in soil at the Manhattan, KS, Biosolids Farm, which has been receiving the city's sewage sludge (also called biosolids) since 1976. The farm is divided into four quadrants. Sludge is injected into one quadrant, one day per week, during a three-month period in a year. The three crops grown in rotation at the Biosolids Farm are winter wheat, sorghum, and corn. One quadrant is fallow at any one time. We observed that after 25 years of application of sludge to the farm, concentrations of seven heavy metals that we measured (Cd, Cu, Fe, Mn, Ni, Pb, Zn) have not increased in the soil, except for Cu, Pb, and Zn. Lead is the only toxic heavy metal, and we did not know the reason for its elevated level. Here we report concentrations of heavy metals in drainage water from the soil at the Biosolids Farm (Table 1). Details of the experiment are given in Liphadzi and Kirkham (2006d). The soil from the Biosolids Farm that had received sludge for 25 years was put in large columns (105 cm depth; 39 cm diameter) in a greenhouse. Data are from columns with no plants and no chelate added to solubilize the heavy metals (control soil). Days after the beginning of the experiment (11 Sept. 2001) are given in the table. At the beginning of the experiment, columns received 20 L water. Between 11 Sept. 2001 and 15 Jan. 2002, 4 L of water were irrigated onto the columns every 2 weeks. No water was added between 15 Jan. 2002 and 2 Feb. 2002. Between 2 Feb. 2002 and 15 May 2002, columns received 9 L of water every 2 weeks.
| Time (days) | Cd | Cu | Fe | Mn | Ni | Pb | Zn |
|---|---|---|---|---|---|---|---|
| 164 | 0.003±0.000 | 0.069±0.001 | 0±0 | 0.017±0.001 | 0.021±0.003 | 0.019±0.003 | 0.020±0.003 |
| 171 | 0.001±0.001 | 0.057±0.003 | 0±0 | 0.015 ±0.016 | 0.017±0.002 | 0.009±0.009 | 0.017±0.006 |
| 199 | 0.003±0.001 | 0.060±0.004 | 0±0 | 0.014±0.012 | 0.016±0.006 | 0.003±0.004 | 0.015±0.004 |
| 217 | 0.009±0.002 | 0.068±0.000 | 0±0 | 0.014±0.005 | 0.030±0.008 | 0.041±0.003 | 0.015±0.001 |
| 232 | 0.005±0.000 | 0.058±0.004 | 0±0 | 0.009±0.006 | 0.019±0.001 | 0.016±0.006 | 0.015±0.004 |
| 246 | 0.002±0.001 | 0.065±0.001 | 0±0 | 0.007±0.001 | 0.023±0.007 | 0.013±0.001 | 0.014±0.001 |
| Mean | 0.004±0.003 | 0.063±0.005 | 0±0 | 0.013±0.004 | 0.021±0.005 | 0.017±0.013 | 0.016±0.002 |
Drinking water standards are (in g/mL): Cd, 005; Cu, 1.3; Fe, 0.3; Mn, 0.05; Ni, none; Pb, 0.015; and Zn, 5.0. Concentrations of Pb in the drainage water were the only ones elevated above drinking water standards, except for Cd in the drainage water 217 days after the beginning of the experiment. The citizens of Manhattan, KS, use surface water for drinking water. Even though this study was done in a greenhouse with columns containing the soil from the Biosolids Farm and may not apply to field conditions, the results suggest that, when the soil is fallow, elevated levels of Pb can leach to the groundwater. Therefore, people using well water that drains from the Biosolids Farm might have slightly elevated levels of Pb in their water.
James Kingston (Ken) McCarron, Visiting Scholar, has accepted a job with the U.S. Park Service in Charleston, South Carolina.
THE WHEAT GENETICS RESOURCE CENTERDepartment 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, W. Li, L. Qi, L. Huang, and D.L. Wilson.
In past years, the WGGRC has evaluated the seedling resistance to leaf rust of Ae. tauschii in the greenhouse after artificial inoculation in more than 550 accessions. From these studies, many resistance genes were found and several have been transferred to elite wheat backgrounds and released as germ plasm. At present, however, promising leaf rust genes in commercial cultivars seem to break down only a few years after a cultivar's release. Now, we hope to identify minor genes at the adult-plant stage that may not give an immune reaction to the leaf rust pathogen but allow the pathogen population to exist without reaching epidemic proportions or causing severe damage to the plant.
We selected a set of 328 lines previously identified as seedling susceptible to isolates PRTUS6 and PMNQ of the leaf rust pathogen. The lines were planted in the field at the Rocky Ford Research Area in Manhattan, KS. Two replications were made for each line. Plants were screened at anthesis for leaf rust infection. A total of 586 hills were planted, of which 12 were Chinese Spring wheat checks and eight were TA2460, a leaf rust-resistant Ae. tauschii line. Along with natural infection, the nursery was inoculated with leaf rust isolates PRTUS42, PRTUS45, and PRTUS50. Disease reaction was scored using the Cobb scale, which gives a percentage of the leaf area covered by pustules of the leaf rust fungus and a letter rating for the size of the pustules. For example, a score of 20MR would indicate 20 % of the leaf area covered with small pustules; a score of 40M would indicate 40 % of the leaf area covered with medium-sized pustules. The control Chinese Spring wheat plants scored a 60-70S, i.e., 60-70 % of the leaf surface was covered with very large pustules.
Of the accessions planted, only four differed significantly in their resistance scores between the replicates. These lines could possibly be segregating for resistance genes in the population or may have escaped some of the infection. Seventy-three lines had resistant (R, very small) type pustules. These lines ranged from 1-50 % coverage. Another 155 lines had moderately resistant (MR, small) type pustules. The spread of the disease in these lines was from 5-70 %. Of the remaining plants, 33 were considered to have medium-sized pustules (M, medium, 10-50 % coverage) and three were moderately susceptible (MS, large, 40-50 % coverage). Leaf rust reaction based on leaf area covered by disease was as follows: 1-5 %, 46 accessions; 10-20 %, 42 accessions; 30-40 %, 114 accessions; and 50-70 %, 62 accessions.
These accessions were all susceptible at the seedling stage however. Based on these results, 15 % of these lines contain one or more genes that can function in the adult plant and will provide another source of resistance genes for improving disease resistance in bread wheat. Selected lines are being grown in a field nursery for additional observations.
Finding diverse sources of FHB resistance is critical for genetic diversity of resistance for wheat breeding programs. L. racemosus is a wild perennial relative of wheat and is highly resistant to FHB. Three wheat- L. racemosus disomic addition (DA) lines DA5Lr#1, DA7Lr#1, and DALr.7 resistant to FHB were used to develop wheat-L. racemosus translocation lines through irradiation and gametocidal gene-induced chromosome breakage. A total of nine wheat-alien translocation lines with wheat scab resistance were identified by chromosome C-banding, GISH, telosomic pairing, and RFLP analyses. The resistance level of the translocation lines with a single alien chromosome segment was higher than the susceptible wheat parent Chinese Spring but lower than the alien resistant parent L. racemosus. All the lines involve nonhomoeologous chromosomes and, thus, are of noncompensating type. We will use ph1b-induced homologous recombination in combination with molecular marker analysis to identify compensating recombinants that still retain the resistance genes.
This work was in cooperation with Drs. P.D. Chen and D.J. Liu, Nanjing Agricultural University, Nanjing, PR China.
Wheat deletion stocks are valuable tools for the physical mapping of molecular markers and genes to chromosome bins delineated by two adjacent deletion breakpoints. The cytogenetic and molecular marker analyses suggest that 1BS-4 resulted from two breakpoints in the 1BS arm and one breakpoint in the 1BL arm. The distal segment from 1BS, except for a small deleted part, is translocated to the long arm. Cytologically, chromosome 1BS-4 is highly stable, but shows a unique meiotic pairing behavior. The short arm of 1BS-4 fails to pair with a normal 1BS arm because of lack of homology at the distal ends. The long arm of 1BS-4 only pairs with a normal 1BS arm within the distal region translocated from 1BS. Therefore, using the 1BS-4 deletion stock for physical mapping will result in the false allocation of molecular markers and genes proximal to the breakpoint of 1BS-4.
Robertsonian translocations are an important step in the transfer of alien genetic variation into wheat. The mechanism of origin of Robertsonian translocations was investigated in plants monosomic for chromosome 1A of wheat and 1Ht of E. trachycaulus by GISH. Chromosomes 1A and 1Ht stayed univalent in all metaphase I cells analyzed, suggesting that Robertsonian translocations do not originate from meiotic recombination in centromeric regions with shared DNA sequence homology. At ana-/telophase I, the 1Ht and 1A univalents underwent either chromosome or chromatid segregation and misdivided in 6-7 % of the pollen mother cells. None of the ana-/telophases I analyzed had Robertsonian translocations, which were only observed in 2 % of the "half tetrads" at ana-/telophase II. The frequency of Robertsonian translocations observed at ana-/telophase II corresponds well with the number of Robertsonian translocations (1-4 %) detected in progenies derived from plants monosomic for group-1 chromosomes of wheat (1A, 1B, and 1D) and 1Ht of E. trachycaulus. Our data suggest that Robertsonian translocations arise from centric misdivision of univalents at ana-/telophase I, followed by segregation of the derived telocentric chromosomes to the same nucleus, and fusion of the broken ends during the ensuing interkinesis. KS04WGRC45, incorporating leaf rust resistance from E. trachycaulus, was developed using this technology.
Virus-induced gene silencing (VIGS) is an important tool for the analysis of gene function in plants. In VIGS, viruses engineered to carry sequences derived from plant gene transcripts activate the host's sequence-specific RNA degradation system. This mechanism targets the RNAs of the viral genome for degradation, and as the virus contains transcribed plant sequence, homologous host mRNAs are also targeted for destruction. Although routinely used in some dicots, no VIGS system was known for monocot plants until the recent report of silencing in barley-by-barley stripe mosaic virus (BSMV). We have developed protocols for use of BSMV to efficiently silence genes in hexaploid wheat. The VIGS system was first optimized in studies silencing phytoene desaturase expression. Next, we used it to assay genes functioning in leaf rust resistance mediated by Lr21, which encodes a nucleotide binding site-leucine-rich repeat class resistance gene product. We demonstrated that infection with BSMV constructs carrying a 150-bp fragment of Lr21 caused conversion of incompatible interactions to compatible, whereas infection with a control construct or one that silences phytoene desaturase had no effect on resistance or susceptibility. Additionally, silencing the RAR1, SGT1, and HSP90 genes, known to be required in many but not all nucleotide binding site-leucine-rich repeat resistance pathways in diverse plant species, resulted in conversion to compatibility, indicating that these genes are essential in Lr21-mediated resistance. These studies indicate that BSMV-VIGS is a powerful tool for dissecting the genetic pathways of disease resistance in hexaploid wheat.
This project is in cooperation with S.R. Scofield, Purdue University, W. Lafayette, IN.
A major QTL, Qfhs.ndsu-3BS, for resistance to Fusarium head blight in wheat has been identified and verified by several research groups. We constructed a fine genetic map of this QTL region and examined microcolinearity in the QTL region among wheat, rice, and barley. Two simple sequence repeat (SSR) markers (Xgwm533 and Xgwm493) flanking this QTL were used to screen for recombinants in a population of 3,156 plants derived from a single F7 plant heterozygous for the Qfhs.ndsu-3BS region. A total of 382 recombinants were identified, and they were genotyped with two more SSR markers and eight sequence-tagged site (STS) markers. A fine genetic map of the Qfhs.ndsu-3BS region was constructed and spanned 6.3 cM. Based on replicated evaluations of homozygous recombinant lines for Type II FHB resistance, Qfhs.ndsu-3BS, redesignated as Fhb1, was placed into a 1.2-cM marker interval flanked by STS3B-189 and STS3B-206. Primers of STS markers were designed from wheat expressed sequence tags homologous to each of six barley genes expected to be located near this QTL region. A comparison of the wheat fine genetic map and physical maps of rice and barley revealed inversions and insertions/deletions. This suggests a complex microcolinearity among wheat, rice, and barley in this QTL region.
Cot filtration (CF) is effective in the characterization of
the gene space of bread wheat, a large genome species (1C = 16
700 Mb). Using published Cot data as a guide, 2 genomic libraries
for hexaploid wheat were constructed from the single-stranded
DNA collected at Cot values > 1,188 and 1,639 M·s.
Compared with sequences from a whole genome shotgun library from
Ae. tauschii (the D genome donor of bread wheat), the CF libraries
exhibited 13.7-fold enrichment in genes, 5.8-fold enrichment in
unknown low-copy sequences, and a 3-fold reduction in repetitive
DNA. CF is twice as efficient as methylation filtration at enriching
wheat genes. This research suggests that, with improvements,
CF will be a highly useful tool in sequencing the gene space of
wheat
U.S. GRAIN MARKETING AND PRODUCTION RESEARCH CENTER
USDA, Agricultural Research Service, Manhattan, KS 66502, USA.
M. Tilley, F.E. Dowell, O.K Chung, S.H. Park, E.B. Maghirang,
B.W. Seabourn, T.C. Pearson, F. Xie, H.P. Akdogan, M.E. Casada,
J.D. Wilson, S.R. Bean, T.J. Schober, P.R. Armstrong, M.S. Caley,
D.L. Brabec, S.Z. Xiao, L.M. Seitz, R.K. Lyne, J.E. Throne, F.H.
Arthur, D.B. Bechtel, G.L. Lookhart, and M.S. Ram.
S.R. Clayshulte, S.D. Haley, P.L. Chapman, B.W. Seabourn, and O.K. Chung.
Environmental conditions significantly affect wheat quality characteristics from year to year. Understanding the effects of environment on quality characteristics and the similarities of genotype response to testing locations is important for breeders selecting test sites and evaluating experimental lines. Six years of quality data from the U.S. Hard Winter Wheat Southern Regional Performance Nursery (SRPN) and the Northern Regional Performance Nursery (NRPN) were analyzed to divide test sites into groups similar in their response to the environment. Cluster analysis divided the SRPN into four clusters based on milling-related variables and three clusters based on rheology-related variables. Locations were consistently placed in the same cluster for the rheology-related variables but not for the milling-related variables. For the NRPN, clustering based either on rheology-related or milling-related variables produced one cluster that contained 58 % of the location-years. However, the remaining location-years were divided into two clusters based on milling-related variables and three clusters based on rheology-related variables. Principal component analysis of the SRPN data identified four principal components based on milling-related variables (explaining 78 % of the total variability) and three principal components based on rheology-related variables (explaining 93 % of the variability). Clustering based on these principal components revealed three clusters for the milling-related variables and four clusters in the rheology-related variables. Interpretation of the principal components allowed clusters to be characterized. Results from either clustering procedure indicate that only a few locations responded similarly to the environment from year to year.
J. Perez-Mendoza, J.E. Throne, E.B. Maghirang, F.E. Dowell, and J.E. Baker.
Primary pests of stored cereals that develop and feed inside grain kernels are the main source of insect fragments in wheat flour. The Food and Drug Administration (FDA) has set a defect action level of 75 or more insect fragments per 50 gram of flour. The current standard flotation method for detecting insect fragments in flour is very labor intensive and expensive. We investigated the potential of near-infrared spectroscopy (NIRS) to detect insect fragments in wheat flour at the FDA defect action level. Fragments counts with both the NIRS and the standard flotation methods correlated well with the actual number of fragments present in flour samples. However, the flotation method was more sensitive below the FDA defect action level than the NIRS method. Although the flotation method is very sensitive at the FDA action level, this technique is time consuming (almost 2 h/sample) and expensive. Although NIRS currently lacks the sensitivity of the flotation method, it is rapid, does not require sample preparation, and could be easily automated for a more sophisticated sampling protocol for large flour bulks. Therefore, this method should be reexamined in the future because NIRS technology is rapidly improving.
P. Armstrong.
During grain storage the quality of grain can be subjected to adverse conditions of high grain moisture and insects. In both instances grain temperature is a good indication when these conditions are present. Most large grain storage facilities use elaborate grain temperature monitoring systems, which require multiple temperature sensors wired to a central computer. Smaller storages do not usually have these systems due to their cost or because the storage is only used for short periods. Wireless sensors, which use radio waves to transmit temperature, may provide a more convenient way to measure grain storage temperature in some cases and can be used for temporary storage or be permanently fixed in the larger storage structures as an alternative to wired sensors. Wireless sensors also have the potential to travel with the grain during distribution. A limiting factor for wireless data transmission is the ability to transmit radio waves through grain with a small, low-power, battery operated device. Tests were therefore conducted with a commercial wireless sensor development system to determine transmission range. These particular wireless sensors were about 2 x 0.5 x 1.5 inches in size. Results showed that data could be transmitted through grain over a 2-m distance at power levels that would allow about 3 years of operation, which is roughly the distance that adjacent wired sensors are placed at for commercial storage. The network ability of these sensors allows them to relay data from sensor to sensor and extend this range infinitely. Wireless sensors have the potential to improve the overall grain storage infrastructure by providing a system that would allow monitoring of storages, which would otherwise not be economically practical.
H. Akdogan, F.H. Arthur, and M.E. Casada.
Insect pests often cause economic damage in stored grain, and cooling storage bins in autumn through aeration (using low-volume airflow rates of ambient air) can be an important component of integrated management plans for stored wheat. Model simulation studies show that a summer aeration cycle would cool stored wheat in Kansas and also reduce insect populations, but field studies have not been done to verify model predictions. We conducted a 3-year study in which summer aeration was included along with aeration in early and late autumn. Summer aeration reduced temperatures in stored wheat and generally reduced insect populations, but year-to-year variations in temperatures affected the level of control. Results warrant further research into the timing and optimization of summer aeration.
F.E. Dowell, E. B. Maghirang, R.A.Graybosch, P.S. Baenziger, D.D. Baltensperger, and L.E. Hansen.
The single kernel sorting system developed to detect specific
grain attributes was commercialized through a CRADA with Perten
Instruments, Stockholm, Sweden. The system was demonstrated at
several international conferences in 2005 and is being publicly
marketed. The system automatically scans individual wheat kernels,
and then sorts kernels based on specific attributes such as protein
content, hardness, and amylose content. The system now is being
used by breeders to select specific traits from early generation
breeder samples and will significantly reduce the time and expense
required to develop cultivars with specific end-use traits. The
system is also being evaluated for use in detecting food safety
attributes such as vomitoxin during routine grading. Although
it was developed for wheat, it is also finding applications in
sorghum and millet.
O.K. Chung, S.H. Park, S.R. Bean, and Z.S. Xiao.
Because of increasing uses of hard winter wheat in other than bread products, the HWWQL included Asian alkaline noodle-making in the quality evaluation of breeding program. Because the textural measurement of cooked noodle quality is too labor-intensive for thousands of breeding lines, we investigated relationships of texture profile analysis (TPA) values of cooked alkaline noodles of 34 HWW with quick tests generally used for bread quality estimation, i.e., SRC, SDS-sedimentation (Sed), computerized-mixograph (C-M), and protein content (PC) and composition. Some typical TPA values of cooked noodles included hardness, resilience, adhesiveness, and cohesiveness. The hardness values were negatively correlated with SDS-sedimentation, 5 % lactic acid (LA)-SRC, and insoluble polymeric protein content (IPP) (r = -0.53 to -0.75), and with PC (r = -0.38, n = 34, P < 0.05). Cohesiveness and resilience were positively correlated with SDS-Sed, 5 % LA-SRC, and IPP (r = 0.61 to 0.74 and 0.46 to 0.72). Both flour PC and IPP were positively correlated with resilience and adhesiveness (r = 0.44 to 0.58). Of many C-M parameters, the height at 8 and 6 min values of C-M showed similar correlations, shown by SDS-Sed. Cooking loss was negatively correlated to resilience and cohesiveness (r = -0.78 and r = -0.80, respectively). Prediction equations were developed by stepwise multiple regression using PC and C-M parameters, resulting in R2 values of 0.67, 0.54, and 0.71 for cooked noodle hardness, resilience, and cohesiveness, respectively. The addition of SRC, SDS-Sed, and/or IPP data, the prediction improved the R2 from 0.54 to 0.62 for only resilience, but for others marginally, indicating the potential use of flour PC and CM-height values for predicting cooked noodle textures for the HWW-breeding program.
Z.S. Xiao, S.H. Park, O.K. Chung, M.S. Caley, and P.A. Seib.
Solvent retention capacity (SRC) was investigated in assessing the end-use quality of hard winter wheat. 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 12-13 % (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.
M.S. Caley, S.H. Park, and O.K. Chung.
Loaf volume (LV) is the principal component of bread quality
evaluation of breeding lines and rapeseed displacement has been
the method of choice for over 60 years at the HWWQL. A new computer-controlled
LV measuring instrument, which employs laser sensor (LS), has
become commercially available. The objective of our study was
to investigate the potential use of the LS instrument for measuring
LV of pup-straight-dough-bread (PUP: 100-g flour) and pound-sponge-&-dough-bread
(POUND: 300-g flour). Using 43 flour samples (19 hard winter
and 24 hard red spring wheat) from the Wheat Quality Council test
samples, harvested in 2004, the LV values by rapeseed were generally
higher than those by LS instrument. The overall average values
of LV by rapeseed were 847 and 2,256 cc for PUP and POUND, whereas
those by LS were 700 and 2,010 cc, respectively. The differences
in LV values obtained between the two methods depend on the LV
values of samples, i.e., a larger difference for a larger loaf
of bread, especially for the PUP (R2 = 0.673) and to lesser degree
for the POUND (R2 = 0.154, P < 0.01). The LV values were highly
correlated between the two methods, irrespective of wheat classes,
baking methods (straight-dough vs. sponge and dough) or sample
size (100- or 300-g flour). The correlations between the two
methods were highest for winter wheat of PUP and POUND (R2 = 0.997)
and lowest for spring wheat PUP (r2 = 0.840). With all 86 data,
R2 value was 0.996. Rapeseed LV values could be predicted significantly
(R2 =0.993) using the LS instrument values such as LV, width,
maximum depth, and area. Therefore, this new LS instrument has
a potential to be used as an objective measurement instrument
of LV for various bread products.
Z.S. Xiao, S.H. Park, O.K. Chung, M.S. Caley, and P.A. Seib.
Computerized mixograph (C-M) has been available for awhile and provides numerous parameters. Due to excessive number of data provided by the software package in C-M, we continued to investigate, more in depth, some of C-M parameters, which would be highly correlated to final quality of straight-dough bread. With 116 hard winter wheat samples, widely ranging protein content (PC) (7-15 %), we analyzed data from C-M, physicochemical quality parameters, SDS sedimentation, and solvent retention capacity (SRC). The peak height is the height of C-M curve at optimum mix time (OMT) and the time-x height (H-x) is the height of C-M curve at 6 min for flours with OMT <6 min and at 8 min for flours with their OMT >6 min. The peak height was highly correlated with PC (r = 0.84) and loaf volume (LV) (r = 0.71, P < 0.0001), and the H-x was also highly correlated with PC (r = 0.71) and LV (r = 0.85). However, we found that the peak height was not able to differentiate the breadmaking performance of flours with a similar PC range, whereas the H-x could. With the set of 37 flours with a PC range of 12-13 %, the H-x was not significantly correlated with PC but highly correlated with LV (r = 0.78) and crumb grain score (r = 0.68, P < 0.001), whereas there were no significant correlations between peak height and PC or LV. We also found that height-x was highly correlated with 5 % lactic acid-SRC test (r = 0.82 and r = 0.83 for a PC range 7-15 % and 12-13 %, respectively, P < 0.001) irrespective of the PC ranges of flour sample set. Among the C-M parameters, H-x was the best parameter to correlate the pup-loaf bread quality (LV and crumb grain scores). Therefore, the H-x value of C-M should be a choice selection as one of the top quality evaluation parameters for hard winter wheat breeding program.
F.E. Dowell, E.B. Maghirang, T.C. Pearson, and D. Brabec.
White wheat is gaining acceptance throughout the Midwest as a class that can improve our competitiveness in export markets. All breeding programs in the Midwest are developing white wheat cultivars. We are able to improve the quality of white wheat cultivars being used in breeding programs by removing wheat of other classes, such as red wheat, from samples using high speed sorting procedures developed through a MOU with Satake, Inc. No other technology is available to remove these contaminating kernels. Almost all white wheat being developed in the Midwest and Pacific Northwest is now shipped to our research unit for purification through our sorter. Our sorting has reduced the development time for these new cultivars by several years, has saved the breeders hundreds of hours, and has salvaged some cultivars that would have been terminated if our technology was not available.
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
1,055 cu cm/100 g flour and crumb grain score of 1.0-5.0. 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.
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 score (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).
S.H. Park, B.W. Seabourn, F. Xie, and O.K. Chung.
Noodle color is an important quality trait to wheat breeders as well as consumers. This study investigated the potential of NIR spectroscopy to predict noodle color and polyphenol oxidase (PPO) content directly from whole grain, meal, and flour. A total of 585 hard winter wheat samples (375 for calibration and 210 for validation) harvested in 2002 and 2003 were used. Reflectance measurements were collected over a wavelength range of 400-2,498 nm. Alkaline noodle dough was made, and color was determined at 0 and 24 hr. PPO activity was also determined from the whole grain, meal, and flour. Unscrambler (v8.0.5), a program for multivariate statistical analysis, was then used to process the spectral data and to develop NIR partial least squares calibration models from the spectra and laboratory data. Calibration models were developed for predicting noodle color (L*, a*, and b* at 0 and 24 hr) and PPO content from grain, meal, and flour. Calibration model R2 for PPO content were generally and unacceptably lower than those for noodle color. For noodle color, the highest R2 value was for L* at 24 hr from flour (0.84 and 0.68 for calibration and validation, respectively), with an RPD of 2.46. Other calibration models for noodle color at 0 and 24 hr from whole grain and meal also showed very comparable R2 values with an even higher RPD. The highest R2 for a* and b* at 24 hr were 0.82 and 0.84 for calibration, and 0.78 and 0.70 for validation with RPD values of 3.23 and 2.98, respectively. The data suggest that there is a good potential for predicting noodle color using NIR spectra from such basic materials as grain, meal, and flour.
M. Tilley.
Chemical oxidants are routinely added to flour to modify rheological properties (shorten mixing time, improve gas retention, lower energy requirement for dough mixing) and enhance bread-making performance (increase loaf volume and improve crumb structure). The elimination of potassium bromate, and possibly other chemical oxidant additives, presents a challenge to the baking industry. Alternative oxidation methods need to be found since industrial baking has been standardized with bromate. Substitution of chemical oxidants with enzymes is a desirable approach because enzymatic reactions are very specific, with little or no reactivity outside of the substrate. Oxidoreducing enzymes such as glucose oxidase (GOX) have been proposed as improvers for the baking industry. The mechanism of improvements caused by GOX is not understood. Following mixing wheat flour with and without the addition of GOX the different protein classes were extracted and analyzed by electrophoresis and size-exclusion HPLC. The most significant effects were observed to occur in the albumin (water-soluble) and gliadin (alcohol-soluble) protein groups. A significant increase in protein concentration and molecular weight distribution was observed in the albumin fraction by SE-HPLC. Further analysis revealed that this is due to changes in gliadin solubility. Gliadins are generally not soluble in water, however the inclusion of GOX in mixing renders the gliadins more water-soluble. The biochemical interactions responsible for this behavior and the possible effects on end-use properties are currently under investigation.
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.
H.P. Akdogan, M. Tilley, and O.K. Chung.
100 % whole wheat (WW) products offer many health benefits by being naturally rich in fiber and bran as well as in B and E vitamins, iron, phytochemicals, and phytoestrogens. 100% WW tortillas have their own sizable market and like other tortilla types their shelf-life and texture play vital importance in consumer acceptance. The literature on 100% WW tortillas is scarce, therefore, this study was performed to evaluate the influence of three different types of emulsifying agents, sodium stearyl lactylate, lecithin, and glyceryl monostearate, on tortilla staling. All samples were subjected to extensibility (tear) tests by using a TA-XT2 Texture Analyzer at days 0, 2, 4, 8, 12, 16, and 20 days of storage. A completely randomized statistical design was chosen. One-way ANOVA was used to analyze the data. No significant difference was found among the means of color attributes of tortillas (L, a, b) or the means of tortilla diameters. The maximum force to tear and gradient (modulus of deformation) were highly correlated to tortilla rollability scores (a scale of 0 to 5 was used, 5 being the most acceptable). Although all emulsifiers improved the shelf-life, lecithin at 2 % resulted in the lowest maximum force to tear at day 0 (softest) and the highest rollability score (3.5/5) at the end of day 20. The control tortillas were the most stretchable (longest distance to tear) at day 0 compared with the tortillas made with emulsifiers. However, at day 20, the control and emulsifier added tortillas did not exhibit a significant difference regarding the distance to tear. Among all three emulsifiers used, lecithin at 2 % level was the most effective to improve the shelf-life and texture of 100 % WW tortillas.
B.W. Seabourn, S.R. Bean, G.L. Lookhart, and O.K. Chung.
Insoluble polymeric proteins (IPP), which are primarily glutenins, are regarded to play an important role in bread-making, particularly dough strength. A number of studies confirm that IPP are directly related to dough strength. One hundred hard winter wheat flours were provided by the USDA-ARS Hard Winter Wheat Quality Laboratory (HWWQL), Manhattan, KS. They were from wheats harvested at two federal regional performance nurseries (RPN) during the 1993-1995 crop years. The flours were selected using the HWWQL-RPN Relational Database based upon their aggregate milling and baking scores, and then analyzed by high performance liquid chromatography for their gliadin and soluble polymeric protein contents, and by Leco Nitrogen Analyzer for IPP content. Using near-infrared reflectance spectroscopy spectral (NIRS) data and multivariate modeling techniques, gliadin and IPP fractions could be predicted with accuracies acceptable for screening purposes (R2 = 0.79). For IPP, the standard error of cross-validation for the model was sufficiently high (R2 = 0.83) for NIRS to be used as an alternative method for measuring IPP content in flour. Results indicate that NIR analysis of flour for IPP (insoluble glutenin) may be very useful in plant breeding programs and quality laboratories where rapid screening of large numbers of flour samples is needed.
B.W. Seabourn, O.K. Chung, P.A. Seib, and P.R. Mathewson.
An infrared spectroscopic method was developed to examine changes in the secondary structure of gluten proteins in a flour-water dough system during mixing. Fourier transform horizontal attenuated total reflectance (FT-HATR) mid-infrared spectra of mixed doughs revealed changes in four bands in the amide III region typically associated with secondary structure of proteins: 1,317 (alpha-helix), 1,285 (beta-turn), 1,265 (random coil), and 1,242/cm (beta-sheet). The largest band, which also showed the greatest change in second derivative band area (SDBA) during mixing (increasing over time), was at 1,242/cm. The bands at 1,317 and 1,285 also showed an increase in SDBA over time. Conversely, the band at 1,265/cm showed a corresponding decrease over time as the doughs were mixed. All bands reached an optimum (or minimum) corresponding to the proper development of the dough as determined by the mixograph. Increases in alpha-helical, beta-turn, and beta-sheet secondary structures during mixing suggest that the dough proteins assume a more ordered conformation, and the decrease of SDBA at 1,265/cm suggests this occurs at the expense of the random coil structural components. These results demonstrate that it is possible, using infrared spectroscopic techniques, to relate the rheological behavior of developing dough directly to changes in the structure of the gluten protein system.
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 optimum mixing time (MT) obtained from the mixograph (MIXO), which is an important rheological property of a wheat flour-water (dough) systems. This method is largely time-consuming and somewhat subjective in its interpretation, especially with regard to mixing tolerance. The objective of this study was to investigate the potential of FT-HATR mid-infrared (IR) spectroscopy to objectively predict optimum MT in a flour/water dough from a short duration mixing cycle (1 min). Fifty-five HRWW flours with varying protein contents (8.7-14.2 %) and MT (1.63-7.38 min) were scanned with three replicates for each sample in the amide III region of the mid-IR (4,000-700/cm) by FT-HATR immediately after being mixed with a MIXO for 1 min. The ratio of the second derivative band areas at 1,335/cm (a-helix) and 1,242/cm (b-sheet) was highly correlated to optimum MT as determined by the MIXO (R2 = 0.81). Results obtained from this study indicated that the FT-HATR technique was able to predict optimum MT very early in the mixing process based upon changes in the secondary structure of the dough protein. This method could be the basis for new technology to rapidly and accurately screen wheat samples in early generation breeding lines, and thus save breeders considerable time and expense in the development of new cultivars.
F. Xie, B.W. Seabourn, O.K. Chung, and P.A. Seib.
Bread-making quality of frozen dough is usually inferior to that of freshly mixed dough. A change in gluten structure during freezing and thawing might be one of the reasons that frozen dough has a poorer end-use performance than fresh dough. We investigated changes in wheat gluten secondary structure resulting from freezing and thawing of flour-water 'model' doughs optimally mixed, using six HRWW flours of varying protein content and optimum mix time. Doughs were scanned in the mid-infrared region of the electromagnetic spectrum using Fourier transform horizontal attenuated total reflectance mid-infrared spectroscopy. Frozen storage time was 0 min, 24 hr, 1 and 2 weeks, and the thawing time was 45 min for all frozen doughs. The protein secondary structures such as b-sheet (1,242/cm), b-turn (1,285/cm), and akpha-helix (1,317/cm) decreased, whereas random coil (1,265/cm) and alpha-helix (1,336/cm) increased, in general, with frozen storage time. The greatest changes for all of the secondary structures occurred within the first 24 hr of frozen storage. For each sample, the most significant change occurred with a decrease in beta-sheet structure. Secondary structure changes in gluten after freezing and thawing cycles were opposite from the changes in secondary structure observed during the dough-mixing and development processes. At present, we do not know if the alteration of secondary structure of gluten resulted from the process of freezing, dough relaxation during thawing or a combination of both. Secondary structural characteristics of gluten protein in frozen and thawed doughs were similar to secondary structural characteristics of an undermixed or undeveloped dough.
J.D. Wilson, D.B. Bechtel, T. Todd, and P.A. Seib.
Starch was isolated from flour of four wheats representing
hard red winter (Karl), hard red spring (Gunner), durum (Belfield
3), and spelt (WK 86035-8) wheat classes. Digital image analysis
(IA) coupled to light microscopy was used to determine starch
size distributions where the volume of granules were calculated
as spherical particles or oblate spheroids. Starch granules were
classified into three size ranges, A-type granules (> 15 µm),
B-type granules (5-15 µm), and C-type granules (< 5 µm).
An error was noted in using digital image analysis because the
perimeter of some granules touch the edge (PTE) of the field being
analyzed. PTE granules are traditionally treated in IA by eliminating
them, and ignoring the errors, or by eliminating half the PTE
particles in the calculations. The error is highest for the largest
granules and the distribution is skewed towards the smaller sized
granules. To correct for this error the PTE granules were manually
replaced into the field by measuring their diameters and entering
them into the database. The results showed differences in the
starch-size distributions between the classes of wheat evaluated,
as well as the method of analysis. Another factor found to affect
the distribution data was the total number of granules counted
per analysis, the 'concentration' effect. In general, the IA
of 5,000 versus 1,000 granules increased the proportion of A-type
granules in a distribution. Four laser diffraction sizing instruments
were used to measure granule distributions of the four classes
of wheat. The minimum sized granules detected in volume % distribution
curves were between 0.4 and 1.2 µm, whereas the largest
granules detected were 44 to 62 µm, dependent on the instrument
and variety of wheat starch. Laser diffraction sizing compared
to IA resulted in a ~40 % underestimation of the A-type granule
diameter and ~50 % underestimation of the B-type granule diameter.
A correction factor (adjustment) was developed from IA data to
correct laser diffraction size analysis. Laser diffraction data
correlations before adjustments to image analysis data, ranged
from R2 = 0.02 (power of ns) to 0.55 (power of ***). After adjustment,
these correlations improved to a range of R2 = 0.72 (power ***)
to 0.93 (power of ***) depending on the class of wheat starch
evaluated.
J.D. Wilson and D.E. Bechtel.
Laser diffraction sizing (LDS) was used to measure particle
size distributions of wheat flour and isolated starch to determine
if the method could be used as a component for predicting end-use
quality. Five hard red winter and five soft red winter wheats
were milled into flour from which starch was isolated. Flour
particle size distributions were measured dry as well as flour
suspended in isopropanol (AACC Method 55-40). Analysis using
isopropanol as a suspension fluid caused smaller particles (<8
µm in diameter) to be released from flour. Use of isopropanol
caused a shift to larger particle sizes between 8 and 400 µm/m
in comparison to dry analysis. Isopropanol also caused clumping
with spurious particles found between 250-400 µm. LDS of
isolated starch showed a separation of A- and B-type granules
between 9.8 and 10.8 µm for the soft wheats and between
8.2 and 9.8 µm for hard wheats. Hard wheats had a larger
volume of starch in the A-type fraction, whereas the soft wheats
had more starch in B- and C-type fractions. A demarcation between
the B- and C-type starch granules was only observed for the soft
wheats and that was when data was presented as percent surface
area. Flour and starch differences were observed between wheat
classes as well as among wheats within a class, LDS may prove
to be a valuable tool in helping predict wheat end-use quality,
an important goal of the grain industry.
S.H. Park, S.R. Bean, J.D. Wilson, and T.J. Schober.
High intensity ultrasound (sonication) was investigated as a method to rapidly purify starch from sorghum and other cereal grains. To improve the process, buffers were optimized to solubilize sorghum proteins in combination with the sonication. Protein content and starch color were determined to evaluate the efficiency of the extraction process. Sonication times, SDS concentration, different types and concentrations of reducing agents (sodium metabisulfite, dithiothreitol, and mercaptoethanol), and centrifugation speeds of the starch washing procedure were tested. Protein content of isolated sorghum starch was reduced to 0-0.14 % (db) after a 2-min sonication (using any of the reducing agents tested). Sodium metabisulfite was chosen as the preferred reducing agent because of its lower toxicity and odor compared to other reducing agents tested. The optimum conditions for producing high purity sorghum starches (0.06% protein) were obtained using the following conditions: 2 min sonication time with 12.5 mM sodium borate buffer, pH 10 containing 0.5 % SDS (w/v), and 0.5 % sodium metabisulfite (w/v) using 1,500 rpm centrifugation speed during starch washing. Starches separated by this method showed significantly less protein content and b values (yellowness) compared with starches separated by enzymatic methods or methods using NaCl solutions and protein extraction buffers with multiple washing steps, both of which take several hours to complete. Differential scanning colorimetry thermogram values for starches isolated by three different methods showed similar patterns except starches obtained with the enzymatic method had slightly higher values of To, Tp, and change of H. Other cereal starches from whole wheat meal, wheat flour, corn, rice, and barley also were rapidly obtained using sonication.
S.H. Park, S.R. Bean, and J.D. Wilson.
Cereal starches have been isolated by hand-washing, wet-milling,
or enzymatic methods (EM). However, these procedures are often
tedious and time-consuming. Therefore, the objectives of this
study were to develop new, rapid and reproducible starch isolation
methods using sonication. Decorticated sorghum flour was sonicated
in a pH 10.0 buffer with 2 % SDS and 2 % reducing agent at a solvent
to sample ratio of 20:1, followed by water-washing. Sonication
times (2, 4, 6, 8, and 10 min) and different reducing agents (ME,
DTT, and sodium metabisulfite) were tested. Protein content of
starch was only 0.35-0.45 % (db) after a 2-min sonication (using
any reducing agent) and was reduced further to 0.15-0.30 % (db)
using longer times. The sonicated starch was comparable to starch
obtained by the EM which takes several hours to complete. Starch
yield (db) and protein content (db) were 74 and 0.83 %, respectively,
for the EM starch, and 74 and 0.42%, respectively, for the sonicated
starch. The color of starch obtained by sonication showed a similar
L (brightness) value, (93.9 versus 93.8) and lower b (yellow)
value (2.99 versus 3.80) than the EM starch. Physicochemical
properties of starches from different types of sorghum (hard versus
soft, normal versus waxy) and the purification of starch from
other cereals will be presented. Wheat, corn, rice, and barley
starches also were rapidly isolated using this procedure.
T.J. Schober, S.R. Bean, and M. Kuhn.
Spelt is an ancient relative of modern bread wheat. Recently,
many spelt cultivars have been bred by crossing spelt and modern
wheat cultivars. Consequently, a wide range of gluten properties
exist in spelt, from very primitive to similar to modern bread
wheat. This wide quality range makes spelt an interesting research
object for the examination of the influence of protein composition
on fundamental rheological gluten properties. Studies were conducted
using 25 European spelt cultivars grown at two locations. Proteins
were fractionated into insoluble/soluble polymeric proteins and
gliadins by a combination of selective extraction, size exclusion
HPLC, and nitrogen combustion. Wet glutens were isolated and
characterized by fundamental rheological methods including dynamic
oscillatory measurements and creep tests. The ranges were 1.6-3.9
kPa, 30.9-40.4 degrees, 6.1-30.5 10-3/Pa, and 41.7-67.0 % for
complex modulus, phase angle, creep compliance, and relative recovery,
respectively. Moisture content of the wet glutens, wet-gluten
content, and SDS-sedimentation volume also were determined and
ranged 61.7-66.0%, 21.4-57.1%, and 9-68, respectively. Rheological
properties were dependant on cultivar as well as on environment.
Cluster analysis performed with the gluten quality data across
environments resulted in three groups of spelt cultivars (1. gluten
properties similar to modern bread wheat; 2. typical spelt; and
3. poor gluten quality). Significant correlations between the
protein fractions and fundamental rheological properties were
found. Overall, spelt is a good model system for an in depth
understanding of gluten.
T.J. Schober, S.R. Bean, and M. Kuhn.
The aim of this study was to understand protein chemistry behind gluten quality of spelt, classify European spelt cultivars based on gluten quality, and compare their protein composition to modern wheat. Gluten quality of two sets of 25 spelt cultivars was studied by fundamental rheology (dynamic oscillatory and creep tests), SDS sedimentation test, moisture content of the wet gluten, and wet-gluten content. These data were compared to the results of size-exclusion HPLC analyses. Significant correlations indicated that the amount of insoluble polymeric proteins (IPP) contributed resistance to deformation in creep tests, elasticity in oscillatory and creep tests, and swelling capacity of the gluten. Gliadins had the opposite effects, whereas the contribution of soluble polymeric proteins (SPP) depended on the type of test. In creep tests, (strain 0.3-1.5) SPP acted similar to gliadins, in oscillation (strain 0.001) they tended to increase elasticity. Spelt, in comparison to HRWWs, was characterized by lower IPP, but higher SPP and gliadins, resulting in softer and less elastic glutens. A wide variation in gluten quality was found within spelt and three groups could be identified by cluster analysis (closer to modern wheat, typical spelt and poor quality).
J. Perez-Mendoza, J.E. Throne, E.B. Maghirang, F.E. Dowell, and J.E. Baker.
Primary pests of stored cereals that develop and feed inside grain kernels are the main source of insect fragments in wheat flour. The Food and Drug Administration (FDA) has set a defect action level of 75 or more insect fragments per 50 gram of flour. The current standard flotation method for detecting insect fragments in flour is very labor intensive and expensive. We investigated the potential of near-infrared spectroscopy (NIRS) to detect insect fragments in wheat flour at the FDA defect action level. Fragments counts with both the NIRS and the standard flotation methods correlated well with the actual number of fragments present in flour samples. However, the flotation method was more sensitive below the FDA defect action level than the NIRS method. Although the flotation method is very sensitive at the FDA action level, this technique is time consuming (almost 2 h/sample) and expensive. Although NIRS currently lacks the sensitivity of the flotation method, it is rapid, does not require sample preparation, and could be easily automated for a more sophisticated sampling protocol for large flour bulks. Therefore, this method should be reexamined in the future because NIRS technology is rapidly improving.ment technology can predict end-use traits, and identify where improvements in rapid prediction technology may be needed.