Flour Swelling Volume Research Articles

Improved multi-trait prediction of wheat end-product quality traits by integrating NIR-predicted phenotypes.

Historically, end-product quality testing has been costly and required large flour samples; therefore, it was generally implemented in the late phases of variety development, imposing a huge cost on the breeding effort and effectiveness. High genetic correlations of end-product quality traits with higher throughput and nondestructive testing technologies, such as near-infrared (NIR), could enable early-stage testing and effective selection of these highly valuable traits in a multi-trait genomic prediction model. We studied the impact on prediction accuracy in genomic best linear unbiased prediction (GBLUP) of adding NIR-predicted secondary traits for six end-product quality traits (crumb yellowness, water absorption, texture hardness, flour yield, grain protein, flour swelling volume). Bread wheat lines (1,400-1,900) were measured across 8 years (2012-2019) for six end-product quality traits with standard laboratory assays and with NIR, which were combined to generate predicted data for approximately 27,000 lines. All lines were genotyped with the Infinium™ Wheat Barley 40K BeadChip and imputed using exome sequence data. End-product and NIR phenotypes were genetically correlated (0.5-0.83, except for flour swelling volume 0.19). Prediction accuracies of end-product traits ranged between 0.28 and 0.64 and increased by 30% through the inclusion of NIR-predicted data compared to single-trait analysis. There was a high correlation between the multi-trait prediction accuracy and genetic correlations between end-product and NIR-predicted data (0.69-0.77). Our forward prediction validation revealed a gradual increase in prediction accuracy when adding more years to the multi-trait model. Overall, we achieved genomic prediction accuracy at a level that enables selection for end-product quality traits early in the breeding cycle.

Environment characterization and genomic prediction for end‐use quality traits in soft white winter wheat

AbstractEnd‐use quality phenotyping is laborious and expensive, thus, testing may not occur until later generations in wheat breeding programs. We investigated the pattern of genotype × environment (G × E) interaction for end‐use quality traits in soft white wheat (Triticum aestivum L.) and tested the effectiveness of implementing genomic selection to optimize breeding for these traits. We used a multi‐environment unbalanced dataset comprised of 672 breeding lines and cultivars adapted to the Pacific Northwest region of the United States, which were evaluated for 14 end‐use quality traits. Genetic correlations between environments based on factor analytic models showed low‐to‐moderate G × E interaction for most traits but high G × E interaction for grain and flour protein. A total of 40,518 single‐nucleotide polymorphism markers were used for genomic prediction. Genomic prediction accuracies were high for most traits thereby justifying the use of genomic selection to assist breeding for superior end‐use quality in soft white wheat. Excluding outlier environments based on genetic correlations between environments was more effective in increasing genomic prediction accuracies compared with that based on environment clustering analysis. For kernel size, kernel weight, milling score, ash, and flour swelling volume, excluding outlier environments increased prediction accuracies by 1–11%. However, for grain and flour protein, flour yield, and cookie diameter, excluding outlier environments did not improve genomic prediction performance.

Genetic Dissection of End-Use Quality Traits in Adapted Soft White Winter Wheat.

Soft white wheat is used in domestic and foreign markets for various end products requiring specific quality profiles. Phenotyping for end-use quality traits can be costly, time-consuming and destructive in nature, so it is advantageous to use molecular markers to select experimental lines with superior traits. An association mapping panel of 469 soft white winter wheat cultivars and advanced generation breeding lines was developed from regional breeding programs in the U.S. Pacific Northwest. This panel was genotyped on a wheat-specific 90 K iSelect single nucleotide polymorphism (SNP) chip. A total of 15,229 high quality SNPs were selected and combined with best linear unbiased predictions (BLUPs) from historical phenotypic data of the genotypes in the panel. Genome-wide association mapping was conducted using the Fixed and random model Circulating Probability Unification (FarmCPU). A total of 105 significant marker-trait associations were detected across 19 chromosomes. Potentially new loci for total flour yield, lactic acid solvent retention capacity, flour sodium dodecyl sulfate sedimentation and flour swelling volume were also detected. Better understanding of the genetic factors impacting end-use quality enable breeders to more effectively discard poor quality germplasm and increase frequencies of favorable end-use quality alleles in their breeding populations.

Effects of Different Grinding Methods on Chemical and Functional Properties of MR211 Rice Flour

Investigation on chemical and functional properties as affected by different grinding techniques was carried out during the milling process of rice grains into rice flour production. Proximate analysis revealed that dry ground flour had significantly (p<0.05) highest protein, lipid, ash and carbohydrate contents. Wet grinding technique yielded flour that exhibit significantly finest average particle size distribution (9.32μm), with significantly lowest damaged starch (4.08%) and highest L* value (93.55). Water absorption index, flour swelling volume and solubility were significantly highest in dry ground flour as compared to others. Results indicated that different grinding methods significantly affected chemical and functional properties of starch and data generated provide additional opportunities of exploiting rice flour utilization and hence boost its value-addition potentials for product development. 

Modeling End‐Use Quality in U.S. Soft Wheat Germplasm

ABSTRACTEnd‐use quality in soft wheat (Triticum aestivum L.) can be assessed by a wide array of measurements, generally categorized into grain, milling, and baking characteristics. Samples were obtained from four U.S. regional nurseries. Selected parameters included test weight, kernel hardness, kernel size, kernel diameter, wheat protein, polyphenol oxidase activity, flour yield, break flour yield, flour ash content, milling score, flour protein content, flour SDS sedimentation volume, flour swelling volume, Rapid Visco Analyzer peak paste viscosity, solvent retention capacity (SRC) parameters, total and water‐extractable arabinoxylan (TAX and WEAX, respectively), and cookie diameter. The objectives were to model cookie diameter and lactic acid SRC as well as to compare exceptionally performing varieties for each quality parameter. Cookie diameter and lactic acid SRC were modeled by using multiple regression analyses and all of the aforementioned quality parameters. Cookie diameter was positively associated with peak paste viscosity and was negatively associated with or modeled by kernel hardness, flour protein content, sodium carbonate SRC, lactic acid SRC, and water SRC. Lactic acid SRC was positively modeled by break flour yield, milling score, flour SDS sedimentation volume, and sucrose SRC and was negatively modeled by flour protein content. Exceptionally high‐ and low‐performing varieties were selected on the basis of their responses to the aforementioned characteristics in each nursery. High‐ and low‐performing varieties exhibited notably wide variation in kernel hardness, break flour yield, milling score, sodium carbonate SRC, sucrose SRC, water SRC, TAX content, and cookie diameter. This high level of variation in variety performance can facilitate selection for improved quality based on exceptional performance in one or more of these traits. The models described allow a more focused approach toward predicting soft wheat quality.

Wheat Quality Requirements for Char Siew Bao Made from Australian Soft Wheat

ABSTRACTAustralia exports 75% of the wheat produced annually, and the Asian region is an important export market for Australian wheat. These markets require suitable quality grain for use in wheat‐based products, so the understanding of wheat end products from an Asian consumer point of view is important. The major wheat quality requirements for char siew bao, a Chinese Guangdong‐style steamed bun, were determined. The research 1) developed laboratory methods for the production and assessment of char siew bao using a scoring system; 2) optimized the new methods and compared the new methods with a traditional method; and 3) used the new validated methods in an investigation of the role of soft wheat quality on char siew bao. A sponge‐and‐dough method with 1 hr fermentation time was developed to establish a simplified laboratory method for char siew bao production. The screening experiments and response surface methodology experiments showed that water addition, sugar, and sponge mixing time were responsible for 69% of the variation in total score. Dough strength was the most important parameter affecting char siew bao quality, followed by flour swelling volume, protein content, and dough extensibility. Both protein and starch quality were important determinants of char siew bao quality.

A Comprehensive Survey of Soft Wheat Grain Quality in U.S. Germplasm

ABSTRACTWheat (Triticum aestivum L.) quality is dependent upon both genetic and environmental factors, which work in concert to produce specific grain, milling, flour, and baking characteristics. This study surveyed all of the 132 soft wheat varieties (cultivars and advanced breeding lines) grown in the U.S. regional nursery system, which encompassed the three main soft wheat producing regions of the United States (eastern and southern soft red winter and western soft white). The quality parameters included test weight, kernel hardness, weight, and diameter, wheat and flour protein, polyphenol oxidase, break flour yield, flour yield, flour ash, milling score, flour swelling volume, flour SDS sedimentation volume, solvent retention capacity (SRC) for water, sodium carbonate, sucrose, and lactic acid, Rapid Visco Analyzer peak pasting viscosity, and cookie diameter. High levels of variation were observed among varieties, regions, and specific environments, with environment being in general a much greater source of variation than varieties. Variety was observed to have a relatively stronger influence on wheat quality in the western nurseries, compared with the eastern and southern regions, where location effects had a stronger impact on overall wheat quality. The greater influence of variety was particularly notable for kernel hardness in the western nurseries. Kernel hardness also varied considerably as a result of environment. For the two soft red winter wheat nurseries, the western U.S. environment produced substantially harder kernels (37–40) compared with the same varieties grown in eastern U.S. locations (15–20). Intertrait quality relationships were observed to be unique to the specific nursery and germplasm in which they were studied, and these relationships were not consistent across nurseries. Nevertheless, on average, soft wheat quality was fairly similar across the United States, indicating that breeding and testing models have been successful in achieving a relatively uniform target for quality. However, many traits showed high levels of variability among varieties, suggesting that a greater level of selection for end‐use quality would benefit end users by increasing consistency and reducing variability. The often large role of environment (location) in quality indicates that end users must be assiduous in their origination and grain procurement. Clearly, “nursery mean” quality does not reflect the potential that can be obtained, as reflected by a few exceptional soft wheat varieties.

Screening of Wheat for Flour Swelling Volume by Near‐Infrared Spectroscopy

ABSTRACTSelection for starch quality is an important consideration in the breeding of wheat for Asian noodles, particularly Japanese udon, and the flour swelling volume (FSV) test was developed for this purpose. Near‐infrared reflectance spectroscopy (NIRS) analysis has also been a key tool in recent years in wheat quality selection. The development and validation of NIRS calibrations for the prediction of FSV on whole grain involved 22 cultivars and breeding lines grown at four locations in two seasons. Eight calibrations were developed, each based on samples from seven trials, with the eighth trial used for validation. Over the eight calibrations, r2 between predicted and actual values was 0.56–0.86 (mean 0.74) and the standard error of prediction (SEP) was 0.77–1.65 (mean 1.14) mL/g of dry meal. Separate calibrations were also developed for hard (n = 461), soft (n = 150), and soft+hard grain (n = 616), with standard errors of cross‐validation (SECV) of 1.03, 1.39, and 1.21 mL/g of dry meal, respectively. Corresponding r2 between predicted and actual values were 0.76, 0.78, and 0.76, respectively. Thus, NIRS offers good potential for the screening of early‐generation lines to identify those with high or low FSV.

Australian wheat for the sponge and dough bread making process

This work investigates the suitability of Australian wheats for the sponge and dough bread market, and determines the wheat quality attributes most important for large loaf volume. A group of 30 genotypes was selected for quality testing and baking using a purpose-developed sponge and dough test baking method. Genotypes were grown at 2 sites in Queensland during winter of 2001 and 2002, and then grain from the field trials was tested in the laboratory. The traits measured included grain, flour, and dough quality, along with loaf volume as the main trait of interest. Glutenin alleles and Wx-B1 allele status of the genotypes were also determined. Genetic correlations were calculated between loaf volume and all the quality traits. The quality trait with the strongest relationship to loaf volume was flour swelling volume. Glutenin alleles and Wx-B1 alleles may also be important for sponge and dough bread quality but the data presented here were insufficient to draw strong conclusions. Consistent, large sponge and dough loaf volumes (&gt;850 cm3) were achieved by the Batavia/Pelsart double haploids QT8753, QT10793, and QT10778. The wheat varieties Hartog and Kennedy also performed well. The work demonstrated that Australia can produce wheat suitable for this market.

Genetic diversity in the physicochemical properties of waxy rice (Oryza sativa L) starch

AbstractThe genetic diversity in the physicochemical properties of starches from 56 waxy rice (Oryza sativa L) genotypes (34 of indica and 22 of japonica) was studied. The parameters included thermal and retrogradation properties tested by differential scanning calorimetry (DSC), pasting viscosity tested by rapid viscoanalyser (RVA), and flour swelling volume (FSV). Wide diversity was found in all the parameters. According to their gelatinisation temperature (GT), the waxy rice genotypes could be divided into two groups, a high‐GT group and a low‐GT group. A total of 15 genotypes were identified as high‐GT, all belonging to the indica subspecies. There was about a 5 °C difference within each group and a 10 °C difference between groups. Many parameters were correlated with each other in all 56 waxy rices, but some correlations were also consistent and significant when comparing the high‐GT group and the low‐GT group separately. For example, hot paste viscosity (HPV) was positively correlated with onset temperature (To) and enthalpy of gelatinisation (ΔHg). The results suggested that initial screening in waxy rice breeding programmes for varieties with desirable starch properties for specific food uses could be efficiently accomplished using pasting profiles from the RVA. Copyright © 2004 Society of Chemical Industry

Analysis of quantitative trait loci for some starch properties of rice (Oryza sativa L.): thermal properties, gel texture and swelling volume

To understand the genetic basis of gelatinization temperature (GT), gel textural traits and flour swelling volume, quantitative trait loci (QTL) were mapped for these traits using a doubled haploid (DH) population derived from a cross between indica variety Zai-Ye-Qing 8 (ZYQ8) and japonica variety Jing-Xi 17 (JX17). The results indicated that the starch property parameters were continuously distributed among the DH lines, and some DH lines showed transgressive segregation for all the parameters. A total of 16 QTLs were identified for seven traits. A major QTL, the alk gene on chromosome 6 was significant for the three GT traits, onset temperature (To), peak temperature (Tp), and completion temperature (Tc). This locus could explain 49.4, 38.9, and 28.3% of the total variance, respectively, indicating that GT parameters were substantially controlled by the alk gene which has previously been identified for alkali spreading value (ASV). The additive effects of alk on To,Tp and Tc were from ZYQ8. Another two QTLs on chromosomes 1 and 7 were also identified for the three GT parameters, whose positive effects were contributed from JX17. Another QTL on chromosome 10 with the positive effects coming from ZYQ8 was significant only for Tc. However, the enthalpy (ΔH) of gelatinization was controlled by two minor QTLs on chromosomes 1 and 7. A major QTL, the Wx gene on chromosome 6 was identified for gel hardness and flour swelling volume which explained 58.8 and 36.6% of the total variances, respectively. Another two QTLs were also detected for flour swelling volume, one of which (qSV-7) could explain 21.4% of the total variance. However, gel cohesiveness was controlled by a major QTL located between alk and Wx on chromosome 6.

Analysis of quantitative trait loci for some starch properties of rice (Oryza sativa L.): thermal properties, gel texture and swelling volume

Abstract To understand the genetic basis of gelatinization temperature (GT), gel textural traits and flour swelling volume, quantitative trait loci (QTL) were mapped for these traits using a doubled haploid (DH) population derived from a cross between indica variety Zai-Ye-Qing 8 (ZYQ8) and japonica variety Jing-Xi 17 (JX17). The results indicated that the starch property parameters were continuously distributed among the DH lines, and some DH lines showed transgressive segregation for all the parameters. A total of 16 QTLs were identified for seven traits. A major QTL, the alk gene on chromosome 6 was significant for the three GT traits, onset temperature (To), peak temperature (Tp), and completion temperature (Tc). This locus could explain 49.4, 38.9, and 28.3% of the total variance, respectively, indicating that GT parameters were substantially controlled by the alk gene which has previously been identified for alkali spreading value (ASV). The additive effects of alk on To,Tp and Tc were from ZYQ8. Another two QTLs on chromosomes 1 and 7 were also identified for the three GT parameters, whose positive effects were contributed from JX17. Another QTL on chromosome 10 with the positive effects coming from ZYQ8 was significant only for Tc. However, the enthalpy (ΔH) of gelatinization was controlled by two minor QTLs on chromosomes 1 and 7. A major QTL, the Wx gene on chromosome 6 was identified for gel hardness and flour swelling volume which explained 58.8 and 36.6% of the total variances, respectively. Another two QTLs were also detected for flour swelling volume, one of which (qSV-7) could explain 21.4% of the total variance. However, gel cohesiveness was controlled by a major QTL located between alk and Wx on chromosome 6.

Asian Salted Noodle Quality: Impact of Amylose Content Adjustments Using Waxy Wheat Flour

ABSTRACTFourteen flour blends of two natural wild‐type wheat (Triticum aestivum L.) flours, ‘Nuplains’ and ‘Centura’, blended with one waxy flour sample were characterized and processed to Asian salted noodles. The flour amylose content range was &lt;1–29%. Damaged starch contents were 10.4, 7.0, and 6.6% for the waxy wheat, Nuplains, and Centura, respectively. The waxy flour farinograph water absorption was as high as 79.5%, ≈20% higher than the wild‐type flours. Because two types of starch granules (wild‐type and waxy) existed in the flour blends, two peaks at 82°C (waxy) and 95°C (wild‐type) were found in the RVA pasting curves. Reduced amylose content caused high flour swelling volume and power and low falling number. Significant effects of flour amylose content on noodle processing and textural (eating) qualities were found in the study. Noodle qualities, as reflected in covariate analysis, were not significantly affected by the flour blend's protein content, SDS‐sedimentation volume, mixograph dough development time, or mixograph tolerance score. The absence of covariate (protein quantity and quality) effects for the food system (flour) used in this study is a very desirable design for the functional studies of starch components. The optimal flour amylose content range for Asian salted noodle products was 21–24%.

Corrigendum to: Genetic mapping of commercially significant starch characteristics in wheat crosses

Starch properties were measured on the doubled haploid progeny of 2 crosses, one between Cranbrook and Halberd and the other between CD87 and Katepwa. Properties studied included starch peak and final viscosity measured by Rapid Visco Analyser, starch granule size distribution measured by laser light scattering, starch gelatinisation temperature by differential scanning calorimetry, and flour swelling volume. In the Cranbrook Halberd cross (samples from 2 environments), a highly significant quantitative trait locus (QTL) was located on chromosome 4A for both starch peak viscosity and starch/flour swelling volume, centred around the Wx-B1 locus. In previous studies, this locus has been found to be linked to Japanese noodle quality. The increases in starch peak viscosity and flour swelling volume are derived from the Halberd parent, consistent with the fact that Halberd is null for the Wx-B1 locus on chromosome 4A and is missing the respective granule-bound starch synthase protein, whereas Cranbrook is a wheat line carrying the normal 3 Wx loci. The final starch viscosity also showed an association with the Wx-B1 locus. In the CD87 Katepwa cross, the progeny showed an association between peak viscosity and a marker on chromosome 7A. This appeared to be near the Wx-A1 locus. In some experiments, flour viscosity showed a highly significant QTL on chromosome 7B, apparently at the same locus as the late maturity - amylase derived from the Cranbrook parent. Starch gelatinisation onset temperature indicated a significant QTL on chromosomes 2B and 7A (LOD = 2.58 and 3.66, respectively, in interval analyses). Starch gelatinisation peak temperatures indicated a QTL on chromosome 7A, which, although not in the significant (P = 0.05) class based on regression analyses, indicated a LOD score of 3.06 in interval analyses. Heat of gelatinisation (H) indicated a suggestive QTL (LRS = 14.5 with a threshold of 14.7 for P &lt; 0.05, LOD = 2.65 for interval analysis), on chromosome 4A, at the Wx-B1 locus with an increased effect coming from the Halberd parent. The A:B granule ratio analysis indicated a significant QTL on chromosome 4B, but this was not observed in all environments and may be due to the fact that the QTL corresponded to the position of a major QTL controlling plant growth.

Genetic mapping of commercially significant starch characteristics in wheat crosses

Starch properties were measured on the doubled haploid progeny of 2 crosses, one between Cranbrook and Halberd and the other between CD87 and Katepwa. Properties studied included starch peak and final viscosity measured by Rapid Visco Analyser, starch granule size distribution measured by laser light scattering, starch gelatinisation temperature by differential scanning calorimetry, and flour swelling volume. In the Cranbrook Halberd cross (samples from 2 environments), a highly significant quantitative trait locus (QTL) was located on chromosome 4A for both starch peak viscosity and starch/flour swelling volume, centred around the Wx-B1 locus. In previous studies, this locus has been found to be linked to Japanese noodle quality. The increases in starch peak viscosity and flour swelling volume are derived from the Halberd parent, consistent with the fact that Halberd is null for the Wx-B1 locus on chromosome 4A and is missing the respective granule-bound starch synthase protein, whereas Cranbrook is a wheat line carrying the normal 3 Wx loci. The final starch viscosity also showed an association with the Wx-B1 locus. In the CD87 Katepwa cross, the progeny showed an association between peak viscosity and a marker on chromosome 7A. This appeared to be near the Wx-A1 locus. In some experiments, flour viscosity showed a highly significant QTL on chromosome 7B, apparently at the same locus as the late maturity - amylase derived from the Cranbrook parent. Starch gelatinisation onset temperature indicated a significant QTL on chromosomes 2B and 7A (LOD = 2.58 and 3.66, respectively, in interval analyses). Starch gelatinisation peak temperatures indicated a QTL on chromosome 7A, which, although not in the significant (P = 0.05) class based on regression analyses, indicated a LOD score of 3.06 in interval analyses. Heat of gelatinisation (H) indicated a suggestive QTL (LRS = 14.5 with a threshold of 14.7 for P &lt; 0.05, LOD = 2.65 for interval analysis), on chromosome 4A, at the Wx-B1 locus with an increased effect coming from the Halberd parent. The A:B granule ratio analysis indicated a significant QTL on chromosome 4B, but this was not observed in all environments and may be due to the fact that the QTL corresponded to the position of a major QTL controlling plant growth.

Physicochemical Properties Related to Quality of Rice Noodles

ABSTRACTEleven rice genotypes with diverse Rapid Visco Analyzer (RVA) pasting characteristics were evaluated for their physicochemical and gel textural characteristics relative to their suitability for making rice noodles. Apparent amylose content (AC) was highly correlated with swelling power (r = ‐0.65, P &lt; 0.05), flour swelling volume (FSV) (r = ‐0.67, P &lt; 0.05), noodle hardness (r = 0.74, P &lt; 0.01), gumminess (r = 0.82, P &lt; 0.01), chewiness (r = 0.74, P &lt; 0.01), and tensile strength (r = 0.72, P &lt; 0.05). Solubility showed an inverse relationship with the pasting parameters and noodle rehydration, and a positive relationship with cooking loss, noodle hardness, and gumminess. FSV and most of the pasting parameters were negatively correlated with noodle hardness. RVA parameters and textural parameters of gels formed in the RVA canister were well correlated with actual noodle texture and may, therefore, be used for predicting rice noodle quality during early screening of genotypes in breeding programs.

Starch and Protein Quality Requirements of Japanese Alkaline Noodles (Ramen)

ABSTRACTStudies on samples of 20 hard‐grained wheat cultivars and a commercial flour that varied in starch and protein quality showed that both characteristics influenced the texture of Japanese alkaline noodles (ramen). Flour swelling volume (FSV) and flour pasting characteristics (peak viscosity and breakdown) determined with a Rapid‐Visco Analyser (RVA) assessed independently of α‐amylase effects, were negatively correlated with total texture score. Protein quality, as indicated by farinograph stability, was positively correlated with total texture score. RVA pasting characteristics were substantially affected by small levels of α‐amylase, and inactivation by means of 1 mM AgNO3 was a critical requirement in characterizing the quality of the starch component of flour.

A Single Genetic Locus Associated with Starch Granule Properties and Noodle Quality in Wheat

An extensive survey of wheat cultivars showed a complete association between the presence of a granule bound starch synthase (GBSS-4A) null mutation and the classification of the respective cultivar into the white salted noodle category. Since flour swelling volume (FSV) is a standard assay of flour used to identify cultivars that have potential for the production of white salted noodles, the results of the survey were investigated further by studying the genetic association of GBSS-4A null genotypes and FSV. A study of 34, F2 derived families, from a cross between wheat cultivars Reeves (good noodle texture, high FSV) and Kulin (poor noodle texture, low FSV), provided clear evidence for the genetic association of a granule bound starch synthase (GBSS-4A) null mutation and FSV. The molecular basis for the affect of the GBSS-4A null mutation was not simply due to a decrease in amylose content in the starch granules. Instead, the null mutation most likely causes a subtle change in starch structure as indicated by the association of high starch viscosity with high FSV and the GBSS-4A null genotype. The study suggests that assaying for the GBSS-4A null mutation at the DNA level may provide a valuable screen for noodle quality at early stages in a breeding program aimed at good white salted noodle quality.

A PCR-based marker for selection of starch and potential noodle quality in wheat

A strong association between the absence of the granule-bound starch synthase (GBSS) protein for the 4A chromosome of wheat and Japanese Udon noodle quality has been previously described. The aim of this study was to identify a molecular marker linked to the GBSS 4A locus which could be used to identify wheat with the desired texture for Udon noodles. PCR primers were designed to target this gene which gave a 440 bp PCR band, corresponding to the presence or absence of the 4A GBSS gene. Of the 268 genotypes screened with these primers, 267 were correctly identified using the PCR primers. The remaining genotype was shown to be heterogeneous for the marker. The PCR marker test developed has advantages over existing methods used to screen for Udon noodle starch quality as it enables high throughput, accurate tests to be carried out on leaves of young seedlings or mature seed and identify breeding lines that are heterogeneous for the 4A allele which will allow for reselections. Application of this PCR test will speed up selection for Udon noodle quality genotypes and reduce breeding costs for production of noodle wheat varieties. Abbreviations: CTAB, cetyltrimethlammonium bromide; FSV, flour swelling volume; GBSS, granule-bound starch synthase; IEF, isoelectric focusing; PCR, polymerase chain reaction; SDS-PAGE, sodium dodecyl sulfate-polyacrylamide-gel electrophoresis.

Physicochemical Properties of Australian Flours Influencing the Texture of Yellow Alkaline Noodles

ABSTRACTFlour properties of 25 Australian wheat cultivars were examined for their relationship to alkaline noodle quality. Rapid Visco Analyzer (RVA) analyses of flours showed that RVA breakdown and final viscosity determined in both water and dilute sodium carbonate were significantly related to the alkaline noodle firmness, elasticity, and surface smoothness. Flour swelling volume (FSV) of flours was negatively correlated with alkaline noodle firmness and elasticity, and positively correlated with surface smoothness of cooked noodles. Use of a dilute sodium carbonate solution led to overall increases in both paste viscosity and FSV. High FSV and low RVA final viscosity values were associated with both the softest noodles and with cultivars containing a null allele for granule‐bound starch synthase on chromosome 4A. Flour protein content and SDS sedimentation volumes were significantly related to noodle texture. The relationship between protein content and noodle firmness was dependent on the Null4A status of the flours and suggested an interaction between starch and protein in determining noodle texture. Multiple regression analysis using flour protein and FSV accounted for 76% of the variation in alkaline noodle firmness. A speculative model of noodle structure was developed based on a concept of the cooked noodle as a composite material.