Gluten Strength Research Articles

Comparative study of the quality characteristics of fresh noodles with regular salt and alkali and the underlying mechanisms

The quality properties of fresh noodles with NaCl and alkali were characterized by rheological, cooking, and texture properties. Microstructure, starch viscosity, protein conformation, gelatinization and protein polymerization during cooking, and water status were determined to investigate the mechanisms underlying their quality differences. The results showed that alkali induced more significantly increased (P < .05) gluten strength and noodle hardness, while NaCl resulted in superior dough extensibility. Pasting viscosity of alkali-flour increased and protein conformation changes were detected in alkaline noodles with increased β-sheet and decreased α-helix structures. Both NaCl and alkali increased cooking loss. NaCl induced a fibrous gluten structure while alkali caused a membrane-like structure. Furthermore, remarkable protein aggregates were observed in alkaline noodles immediately after 2 min of cooking in non-reduced HPLC patterns, while 4 min in reduced patterns. Water–solids interaction in alkaline noodles was enhanced with decreased water mobility. NaCl induced no significant changes in protein aggregation and water status.

Genome-Wide Association and Prediction of Grain and Semolina Quality Traits in Durum Wheat Breeding Populations.

Grain yield and semolina quality traits are essential selection criteria in durum wheat breeding. However, high phenotypic screening costs limit selection to relatively few breeding lines in late generations. This selection paradigm confers relatively low selection efficiency due to the advancement of undesirable lines into expensive yield trials for grain yield and quality trait testing. Marker-aided selection can enhance selection efficiency, especially for traits that are difficult or costly to phenotype. The aim of this study was to identify major quality trait quantitative trait loci (QTL) for marker-assisted selection (MAS) and to explore potential application of genomic selection (GS) in a durum wheat breeding program. In this study, genome-wide association mapping was conducted for five quality traits using 1184 lines from the North Dakota State University (NDSU) durum wheat breeding program. Several QTL associated with test weight, semolina color, and gluten strength were identified. Genomic selection models were developed and forward prediction accuracies of 0.27 to 0.66 were obtained for the five quality traits. Our results show the potential for grain and semolina quality traits to be selected more efficiently through MAS and GS with further refinement. Considerable opportunity exists to extend these techniques to other traits such as grain yield and agronomic characteristics, further improving breeding efficiency in durum cultivar development.

Conditional and unconditional QTLs mapping of gluten strength in common wheat (Triticum aestivum L.)

AbstractDissecting the genetic relationships among gluten-related traits is important for high quality wheat breeding. Quantitative trait loci (QTLs) analysis for gluten strength, as measured by sedimentation volume (SV) and gluten index (GI), was performed using the QTLNetwork 2.0 software. Recombinant inbred lines (RILs) derived from the winter wheat varieties Shannong 01-35×Gaocheng 9411 were used for the study. A total of seven additive QTLs for gluten strength were identified using an unconditional analysis. QGi1D-13 and QSv1D-14 were detected through unconditional and conditional QTLs mapping, which explained 9.15–45.08% of the phenotypic variation. QTLs only identified under conditional QTL mapping were located in three marker intervals: WPT-3743–GLU-D1 (1D), WPT-7001–WMC258 (1B), and WPT-8682–WPT-5562 (1B). Six pairs of epistatic QTLs distributed nine chromosomes were identified. Of these, two main effect QTLs (QGi1D-13 and QSv1D-14) and 12 pairs of epistatic QTLs were involved in interactions with the environment. The results indicated that chromosomes 1B and 1D are important for the improvement of gluten strength in common wheat. The combination of conditional and unconditional QTLs mapping could be useful for a better understanding of the interdependence of different traits at the QTL molecular level.

Wide crosses of durum wheat (Triticum durum Desf.) reveal good disease resistance, yield stability, and industrial quality across Mediterranean sites

Durum wheat (Triticum durum Desf.) breeders over the past century have increased the productivity and resilience of this crop via strong selection applied to genes controlling agronomically important traits. Along this process, some of the primitive genetic diversity of this species was lost. A debate exists on whether or not some of the original primitive diversity should be re-introgress into modern germplasm in order to facilitate new improvements. Here, the possible negative effects of re-introducing primitive diversity were assessed by comparing the performances of three ICARDA elites and four commercial cultivars against seventeen durum wheat wide crosses, generated by hybridization of elites and Triticum dicoccoides, T. araraticum, and Aegilops speltoides. The material was grown in Lebanon, Algeria and 10 environments in Morocco. Tested under natural inoculation against Lr14a virulent strains of leaf rust as well as tan spot races 4 and 6, revealed that wide crosses had significantly higher levels of resistance. Further, the use of a selection index that combined selection for grain yield potential and stability revealed that 14 wide crosses performed better than any of the elites or cultivars. Finally, testing quality traits at four sites revealed that wide crosses had significantly higher grain size and protein content than the other two germplasm classes, while no significant difference could be observed for gluten strength. Only in the case of yellow pigment, an industrially important trait for durum wheat, one variety (‘Tomouh’) outperformed all other classes, even though wide crosses lines also achieved good scores. Hence, it was not possible to identify any negative drag in the use of wide crosses for improving durum wheat modern germplasm, with the partial exception of yellow pigment.

Molecular characterization of γ gliadin from durum wheat (&lt;i&gt;Triticum turgidum L. Subsp. Durum&lt;/i&gt; ((Desf.) Husn.)

The gluten quality is one of the main factors affecting the quality of durum wheat. It depends primarily on its storage proteins composition (glutenins and gliadins). In order to set up and initiate a technological quality improvement program of durum wheat we have conducted a prospection of the different protein sequences of gliadin in different databases for Triticum, then the filtration steps and assembly by appropriate software have been conducted to reduce the number of redundant sequences. On the other hand, we have isolated a gene from Iride Gli-A1 encoding a γ-gliadin protein associated with gluten strength and viscoelasticity of the dough, we performed an in silico molecular and structural analysis in order to define its putative functional properties. The latter could be a valuable candidate as molecular marker for selecting high nutritive value of durum wheat and/or for genetic improvement of durum wheat quality.

Kernel vitreousness and protein content: Relationship, interaction and synergistic effects on durum wheat quality

Four sets of durum samples were used in this study to further understand the interrelationships among hard vitreous kernels (HVK), protein content, and pigment concentration, with a focus on the interaction and synergistic effects of protein content and vitreousness on durum quality. HVK level increases with higher protein content in the range of 9.5–12.5%, but this relationship is less evident in durum samples with high protein content (12.5–14.5%). Both protein content and kernel vitreousness can significantly affect durum milling quality. White starchy kernels (WSK) in low protein durum have a very detrimental impact on milling and pasta processing quality, but high protein content can mitigate the adverse impact of WSK on durum quality. Although protein content plays a dominant role, higher HVK might contribute positively to pasta firmness. There was no significant difference in yellow pigment content between HVK and WSK. However, pigment loss from semolina to dough was higher for WSK than HVK. Despite the difference in protein content, HVK and WSK have little difference in gluten strength. The monomeric protein was preferentially accumulated in HVK. The glutenin proteins of HVK and WSK were similar in the ratios of HMW-GS 1Bx/1By and HMW/LMW-GS.

Gluten Aggregation Behavior in High‐Shear‐Based GlutoPeak Test: Impact of Flour Water Absorption and Strength

Gluten aggregation behaviors of wheat flour were evaluated using a high‐shear‐based method with the GlutoPeak instrument and related to flour functional properties. GlutoPeak peak time (PT) and peak area (PA) were positively associated with gluten strength but negatively affected by farinograph absorption (FAB). GlutoPeak maximum torque (Tmax) was highly positively (P &lt; 0.001) correlated with FAB regardless of gluten strength. PT and PA increased with the decrease of FAB. This could result in overestimation of gluten strength owing to water absorption. To account for the impact of FAB, a new parameter GlutoPeak strength index (GSI) was introduced for predicting gluten strength. GSI was obtained by multiplying Tmax and PA. This arithmetic product was found to provide greater correlation (r = 0.91) with dough strength than those of PA (r = 0.84) or PT (r = 0.57) based on the analysis of 56 advanced breeding lines with wide range of FAB. Moreover, significant relationships were found between GSI and flour mixing and baking properties. Using 8 g of flour and with a test time of less than 10 min, the GlutoPeak instrument shows great potential as a rapid tool for gluten strength selection.

Impact of Characteristics of Different Wheat Flours on the Quality of Frozen Cooked Noodles

In this study, the impact of characteristics (physicochemical, rheological, and pasting properties) of different wheat flours on the quality of frozen cooked noodles was investigated. In this sample set, results showed the cooking loss of noodles related negatively to flour swelling power. The water absorption of noodles related negatively to the dough stability time, the area, and the resistance to extension. The wheat flour with higher dough development time resulted in frozen cooked noodles with higher hardness, chewiness, and adhesiveness. Springiness of noodles correlated negatively to degree of softening. The tensile properties of frozen cooked noodles were influenced by rheological and pasting properties of wheat flours. The present study indicated high quality of frozen cooked noodles demanded wheat flours with high dough gluten strength, peak viscosity, and final viscosity and with low pasting temperature.

Effect of Salt Reduction on Dough Handling and the Breadmaking Quality of Canadian Western Red Spring Wheat Varieties

The effect of salt (NaCl) on the breadmaking quality of 37 varieties of Canadian Western Red Spring wheat (Triticum aestivum L.) was investigated along with dough stickiness for a 20 variety subset. A principal components analysis indicated that dough development time (DDT), mixing tolerance index (MTI), and stability (STA) were highly correlated. DDT showed an inverse relationship with MTI (r = –0.73) and a positive relationship with STA (r = 0.89). STA was also negatively related to MTI (r = –0.76). A reduction of salt from 2.0 to 1.1% (based on flour weight) was considered from a practical perspective. Each variety responded differently to salt reduction. Obtaining an optimal dough consistency with less salt required less work input and shorter mixing time. Overall, decreasing loaf volume with reducing salt content was observed, although certain varieties produced the opposite effect. This suggests that for a particular flour, depending on the inherent flour strength, there is a level of NaCl that produces an optimum between gluten strength and gas‐holding capacity of the dough, resulting in a loaf with good crumb texture and an even distribution of bubble sizes. A stickiness test was performed on selected varieties to evaluate the dough handling properties at 1.1 and 2.0% salt levels. The overall trend showed an increase in stickiness with a decrease in the salt content; however, certain varieties showed no change.

End‐Use Quality of CIMMYT‐Derived Soft‐Kernel Durum Wheat Germplasm: II. Dough Strength and Pan Bread Quality

Durum wheat (Triticum turgidum ssp. durum) is considered unsuitable for the majority of commercial bread production because of its weaker gluten strength, combined with a larger flour particle size and higher level of starch damage after milling. Recently, a new durum cultivar with soft kernel texture, Soft Svevo, was developed by the Ph1b‐mediated homoeologous transfer of the Puroindoline genes at the Hardness (Ha) locus from the D genome of T. aestivum L. The objective of this research was to evaluate the dough strength and pan bread‐making potential of soft‐kernel durum germplasm developed from crossing Soft Svevo to selected entries of the International Maize and Wheat Improvement Center (CIMMYT) 44th International Durum Yield Nursery. Forty‐six F2:5 soft durum full and half‐sib lines were grown in replicated plots in two locations. Grain samples were evaluated for flour protein quality, dough mixing, and strength characteristics and bread baking. Significant differences (p &lt; 0.05) were detected among lines for flour sodium dodecylsulfate (SDS) sedimentation volume (3.2–12.6 mL g−1), solvent retention capacity lactic acid (63.2–112.6 g 100 g−1), Mixograph water absorption (59.8–64.5 g 100 g−1), peak height (37.1–52.8), and peak width (55.4–125.2), and loaf volume (629–864 cm3).These results indicate that the bread‐making potential of soft durum can be improved if hard durum cultivars with favorable alleles for protein quality, dough strength, and bread making are chosen as crossing parents with Soft Svevo and, by extension, other soft‐kernel durum wheat germplasm.

Enriching novel Glu-Ax alleles and significantly strengthening gluten properties of common wheat through wide hybridization with wild emmer

Two hybrids, BAd7-209 and BAd7-210, were obtained by wide hybridization between wild emmer D97 and weak gluten cultivar CN16. They had a genetic background of common wheat, resulting from continuous selfing over nine times. These hybrids were better than CN16 in dough quality and processing quality tests. BAd7-210 was better than medium gluten wheat cultivar MM37, and BAd7-209 was far better than moderate to strong gluten wheat cultivar SM482. Through chromosome engineering, BAd7-210 possessed the 1Ax2.2 of male D97, and BAd7-209 had the 1Ax1.2 which was caused by complex variation because of cross-parents’ genomic asymmetry. The open reading frames (ORFs) of two novel active Glu-Ax alleles 1Ax2.2 and 1Ax1.2 were 2496 bp and 2514 bp, encoding 830 and 836 amino acid residues, respectively. The 1Ax1.2 was the second longest Glu-Ax gene discovered to date, and it had two deletions and one insertion besides many single nucleotide polymorphisms (SNPs) compared with the 1Ax2.2 and 1Ax1. The longer polypeptide of 1Ax1.2 should explain why BAd7-209 has better processing quality than BAd7-210. Therefore, wild emmer could be effectively utilized to enrich the 1Ax alleles of common wheat through direct cross transferring and generating novel allele variation, which could significantly enhance the gluten strength.

Protein polymerization and water mobility in whole-wheat dough influenced by bran particle size distribution

The influences of bran particle size distribution on the protein polymerization and water mobility in whole-wheat dough (WWD) were investigated. Four bran particle size distributions were obtained by fine-grinding treatments and the mean particle sizes of reconstituted whole-wheat flour (WWF) were 242, 160, 114, and 45 μm, respectively. Mixolab parameters showed that WWF water absorption was increased with reduced bran particle size, and the 160 μm group exhibited a higher stability than any other WWF group. A more continuous gluten matrix and a more compact structure were observed in the 160 μm group due to its moderate bran particle size. Protein secondary structure analyses indicated the increased β-sheet conformation and reduced β-turns structure in the 160 μm group, demonstrating a more polymerized and stable gluten network formed. Additionally, 1H NMR measurements showed larger populations of tightly bound water in WWD due to the presence of arabinoxylan, and confirmed the strengthened gluten strength in the 160 μm group by indicating increased water availability to gluten proteins. The results suggest that modifying bran particle size is a potential method for protein polymerization enhancement and gluten formation improvement in WWD, but appropriate bran particle size is needed to strengthen gluten network.

Transglutaminase-set colloidal properties of wheat gluten with ultrasound pretreatments

The low solubility of wheat gluten limits its accessibility. This work aimed to study the impact of ultrasonic pretreatments on the gelation of wheat gluten. The pretreatments included ultrasound combined with alkali, urea, Na2SO3, with or without the addition of transglutaminase (TGase). The gel strength of wheat gluten was 287g/cm2 after treatment with Na2SO3/ultrasound/TGase. The free sulfhydryl and disulfide bond content was significantly affected by ultrasound treatment. After treatments including TGase crosslinking, the molecular weight of wheat gluten complexes became larger. The network formed by the wheat gluten was transformed into a dense and homogenous structure after the pretreatment with Na2SO3/ultrasound/TGase. The content of random coil of wheat gluten increased. The gelation of wheat gluten could also be significantly enhanced by Na2SO3/ultrasound treatment followed by TGase treatment. Using physical and chemical pretreatments to allow TGase to enhance the gelation of wheat gluten may increase its uses as a food additive.

High molecular weight glutenin subunits and the classification used in Brazilian wheat industry.

Industrial wheat quality flour is related to gluten amount in grain. This study aimed to evaluate the relationship between high molecular weight (HMW) glutenins obtained by SDS-PAGE and gluten strength (W) obtained by the alveograph test and cropping environmental effect on wheat flour quality for Brazilian industry. Fifty-one cultivars/breeding lines were evaluated in three environments. The W value and HMW glutenin score were evaluated by SDS-PAGE. The environment effects on wheat flour were also evaluated. There was a relationship between the W value used in wheat flour industrial classification and score 10 of HMW glutenins, but there was no relation with scores 9 or lower. Cultivars/breeding lines with score 10 of HMW glutenin are less susceptible to environmental effects and produce breeding type wheat flour (W value ≥300) of interest for industry. The cultivars/breeding lines with score 10 for HMW glutenins is the main choice for a wheat breeding program.

Frequent occurrence of high molecular weight glutenin subunit (HMWGS) combinations in high yielding popular Indian bread wheat and their impact on end-usages

Grain quality data of 546 high yielding bread wheat entries evaluated in different zones of India during the period 200516 was examined to identify the frequently occurring HMWGS combinations and the ones suited for the endusages. Although 24 HMWGS combinations occurred in the studied material, only six had frequency of more than 5%, namely, 5+10, 2*, 17+18; 2+12, 2*, 17+18; 5+10, 2*, 7+9; 2+12, 2*, 7+9; 5+10, 1, 7+9 and 2+12, 2*, 7+8. Out of these, only two viz., 5+10, 2*, 17+18 and 2+12, 2*, 17+18 had distinction of making good quality bread as well as chapati. Another combination, 2+12, 2*, 7+9 suited well for bread making but it lacked in chapatti quality. Impact of HMWGS combinations could be seen on biscuit quality also as spread factor in 2+12, 2*, 7+8 was significantly higher than all other combinations. Gluten strength and gluten quality was best observed in 5+10, 2*, 17+18 combination. Besides gluten properties and end-products quality, differences were also observed in the inter-product relationship. In the combinations best suited for bread and chapatti i.e., 5+10/2+12, 2*, 17+18; quality of bread and chapati remained unrelated. The well-known inverse relationship between biscuit and bread/chapati could only be observed in 5+10, 2*, 17+18 combination. Negative association between biscuit and bread/chapatti was also observed in the best biscuit suited combination i.e. 2+12, 2* 7+8. Study underlined that spread of HMWGS is not uniform under Indian conditions and only few combinations are needed to facilitate value addition in the country.

A novel compensating wheat-Thinopyrum elongatum Robertsonian translocation line with a positive effect on flour quality.

Wheat flours are used to produce bread, pasta, breakfast cereals, and biscuits; the various properties of these end-products are attributed to the gluten content, produced as seed storage proteins in the wheat endosperm. Thus, genes encoding gluten protein are major targets of wheat breeders aiming to improve the various properties of wheat flour. Here, we describe a novel compensating wheat–Thinopyrum elongatum Robertsonian translocation (T1AS.1EL) line involving the short arm of wheat chromosome 1A (1AS) and the long arm of Th. elongatum chromosome 1E (1EL); we developed this line through centric breakage-fusion. Compared to the common wheat cultivars Chinese Spring and Norin 61, we detected two additional 1EL-derived high-molecular-weight glutenin subunits (HMW-GSs) in the T1AS.1EL plants. Based on the results of an SDS-sedimentation volume to estimate the gluten strength of T1AS.1EL-derived flour, we predict that T1AS.1EL-derived flour is better suited to bread-making than Chinese Spring- and Norin 61-derived flour and that this is because of its greater gluten diversity. Also, we were able to assign 33 of 121 wheat PCR-based Landmark Unique Gene markers to chromosome 1E of Th. elongatum. These markers can now be used for further chromosome engineering of the Th. elongatum segment of T1AS.1EL.

Assessment of chapatti quality of wheat varieties based on physicochemical, rheological and sensory traits.

Fifty wheat varieties were assessed for chapatti quality using grain characteristics, dough rheological properties and pasting characteristics. Results revealed that 88% of wheat varieties studied were medium-hard to hard based on kernel texture. Water absorption and damaged starch were found to be important parameters for chapatti quality as both parameters had significant positive effect on the pliability and puffing height of chapatti. Protein content and gluten strength parameters like SDS sedimentation volume, dough stability and gluten index were found to have a negative impact on chapatti quality. Based on chapatti quality assessment the wheat varieties were classified into four distinct clusters viz. good, acceptable, fair and poor for chapatti making. It was elucidated that 46% of the varieties studied were good to acceptable for chapatti making, while 54% resulted in fair or poor chapatti quality thereby clearly indicating the need to establish and substantiate the development of product-specific varieties.

Microstructural, textural, and sensory properties of whole-wheat noodle modified by enzymes and emulsifiers.

With the utilization of enzymes including endoxylanase, glucose oxidase (GOX) and transglutaminase (TG), and emulsifiers comprising sodium stearoyl lactate (SSL) and soy lecithin, the microstructural, textural, and sensory properties of whole-wheat noodle (WWN) were modified. The development time and stability of whole-wheat dough (WWD) were enhanced by TG due to the formation of a more compact gluten network, and by SSL resulting from the enhanced gluten strength. Microstructure graphs by scanning electron microscopy (SEM) verified that TG and SSL promoted the connectivity of gluten network and the coverage of starch granules in WWN. TG increased the hardness and elasticity of cooked WWN, while two emulsifiers increased the noodle cohesiveness. Additionally, TG and SSL improved the sensory properties of noodle such as bite, springiness, and mouth-feel. The results suggest that TG and SSL are effective ingredients in enhancing the gluten strength of WWD and improving the qualities of WWN.

Quality assessment with HPLC in released varieties of tetraploid (Triticum durum Desf.) wheat from Ethiopia and Spain

Quality of durum wheat is of importance for pasta production. Our aim was to evaluate the quality of released durum wheat at Ethiopia by the use of pheno-quality traits as well as composition and amount and size distribution of proteins; these attributes were also compared with the same ones for Spanish released wheat grown in the same environment. Large variation was obtained among the released durum wheat for all parameters investigated. The evaluation of protein parameters indicated the varieties Klinto, LD-357, Tob-66 and Ude to have suitable protein composition for pasta production, while Tob-66 showed high protein concentration and Tob-66, LD-357 and Yerer showed high gluten strength. The most promising Ethiopian variety for pasta production as to the results from the present study was Tob-66. Also, LD-357 showed promising protein characteristics, although the kernels were white, which is not desired for pasta production. Some of the evaluated varieties might be of interest for production of local leavened bread although the quality is not good enough for pasta production.

GlutoPeak: A Breeding Tool for Screening Dough Properties of Durum Wheat Semolina

A rapid shear‐based test using a GlutoPeak instrument was compared with tests commonly used by durum wheat breeders to assess the potential of this instrument to discriminate between samples. Thirty‐two durum wheat semolina samples were analyzed by mixograph, SDS sedimentation (SDSS), gluten index (GI), and GlutoPeak testing. A subset was also tested for pasta quality. GlutoPeak peak maximum time (PMT) was the best indicator of gluten strength and correlated well with the other tests except SDSS. Samples with higher levels of SDS‐unextractable glutenin (insoluble protein [IP]) had stronger dough and longer PMT, but the GlutoPeak test only correlated with pasta stickiness using a smaller set of samples. The range in mixogram profiles encountered in breeding material was related to the IP content, and the pasta made from the different types was of similar quality, differing more because of protein content rather than mixogram type. The GlutoPeak test is faster than GI and uses less sample, requires little technical skill, and is suitable for evaluating large numbers of breeder's lines. The GlutoPeak test is best suited to discriminating weak from strong dough samples and allows for testing with small samples, thus facilitating quality evaluations at early stages of a breeding program.