Glutenin Subunits Research Articles

Influence of high-molecular-weight glutenin subunits and salt types on dough rheology and gluten aggregation: A combined experimental and computational approach

This study investigates the impact of various salts (NaCl, KCl, CaCl₂, MgCl₂) on gluten aggregation, with an emphasis on the role of high-molecular-weight glutenin subunits (HMW-GS) in modulating these impacts. The results demonstrated that NaCl significantly improved dough springiness and adhesiveness, while divalent salts like CaCl₂ and MgCl₂ had a greater effect on increasing dough hardness, with KCl showing the least impact among all salts. Differential responses were observed in HMW-GS deletion lines, where Bx7 was more responsive to NaCl and CaCl₂, whereas By8 showed stronger interactions with KCl and CaCl₂. The observed reductions in zeta potential and decrements in ionic bond content during salt-induced gluten aggregation supported the 'electrostatic shielding' mechanism, with hydrophobic interactions and hydrogen bonding emerging as key contributors to aggregate stability. Molecular dynamics simulations further corroborated these findings, revealing stronger Coulomb-SR interactions and enhanced binding affinities for divalent ions, in agreement with experimental data. These insights provide a theoretical foundation for optimizing low-sodium formulations in wheat-based products.

Unveiling the mechanism of high-molecular-weight glutenin subunit deletions at the Glu-B1 locus affecting gluten deterioration during dough frozen storage and freeze-thaw cycles: An integrative experimental and in silico study

This study explored how high-molecular-weight glutenin subunits (HMW-GS) at the Glu-B1 locus impact gluten deterioration during dough frozen storage and freeze-thaw (F/T) cycles. Using deletion lines, we found that the deletion of specific HMW-GS, particularly Bx7, led to a greater reduction in glutenin macropolymer (GMP) wet weight during storage, especially under F/T cycles. The frozen conditions triggered more dissociation of hydrogen and disulfide bonds, generating more protein monomers and resulting in severe gluten deterioration in the Bx7 deletion. Additionally, protein structures in these lines were more vulnerable to damage during F/T cycles due to temperature fluctuations. In silico analysis further confirmed that Bx7 had better stability and antifreeze activity compared to By8, explaining why its deletion had a more pronounced effect on gluten stability. These findings offer significant implications for the food industry, particularly in enhancing the quality, shelf-life, and commercial viability of frozen dough products by providing a deeper understanding of the mechanisms behind gluten deterioration, specifically the role of high-molecular-weight glutenin subunits.

Effect of sulfur and potassium foliar applications on wheat grain protein quality

ContextThe effects of sulfur and potassium fertilizers on wheat yield and quality have been well studied, but most of them are used as basal fertilizers. However, the root system is senescent at the later stages of wheat growth and cannot absorb sufficient sulfur and potassium fertilizers plant needed. It is still unclear whether sulfur and potassium foliar applications at the later stages can affect wheat yield and quality. ObjectiveThis experiment was conducted to investigate the changes of sulfur and potassium accumulation and transport, protein synthesis and flour processing quality after foliar application of sulfur and potassium fertilizers, transport and the relating physiological mechanisms. MethodsIn 2020–2021 and 2021–2022, a three-factor split plot experiment was carried out in the middle and lower reaches of Yangtze River, with wheat variety, concentration of sulfur fertilizer and potassium fertilizer served as main factor, subfactor and sub-subfactor respectively. ResultsIn the study from 2020 to 2022, the albumin protein content of both varieties decreased in the nutrient spraying treatment, particularly in the high potassium level. However, there was no significant effect on the globulin content. Moreover, the gliadin protein content decreased in the sulfur spraying treatment alone, but significantly increased the wheat gluten content, and thereby the total protein content. We also found significant genotypic differences in the composition and content of high molecular weight wheat glutenin subunits (HMW-GS) between the two varieties. The foliar spraying of sulfur and potassium fertilizers significantly increased the content of subunits 1 and 8 in Yangmai (YM15) and subunits 7 and 12 in Yangmai (YM16), and the effect of mixed spraying was better than single-nutrient spraying, especially the amount of 0.2 % sulfur and 0.3 % potassium fertilizer treatment. ConclusionsThe superimposed effect of sulfur and potassium effectively increased the total protein content by promoting the accumulation of sulfur in transit to the seeds, increasing the substrate supply level, and enhancing enzyme activity. Although sulfur and potassium combination can improve the grain protein quality and flour processing quality, too high spraying concentrations can decrease the flour processing quality. ImplicationsSpraying the appropriate amount of 0.2 % sulfur and 0.3 % potassium fertilizer can serve as an optimization measure for high-quality and efficient production of different types of wheat varieties.

The association of glutenin subunit composition to baking quality traits of spring and winter wheat in Estonia

In Estonian local mills, protein content (PC) and wet gluten content (WGC) are among the main indicators considered and evaluated when purchasing grains. Protein composition also significantly affects baking quality. The baking quality of ten winter wheat (WW) and spring wheat (SW) varieties was studied at the Center of Estonian Rural Research and Knowledge (METK). PC, WGC, gluten index (GI), and dough stability time (DST) were higher in SW varieties. PC was positively correlated with WGC and loaf volume (LV) in both wheat types. PC and WGC were negatively correlated with GI and positively correlated with DST only in WW. The viscoelastic properties of dough are linked to its high- and low molecular weight glutenin subunits (HMW-GS and LMW-GS). The allelic composition of the glutenin genes was determined using DNA markers. All the studied varieties had the allele Glu-D1d and additional allele Glu-D1a was found in the variety ‘Voore’. Fourteen varieties had Glu-A1a and b alleles associated with improved backing quality. Alleles Glu-B1с and Glu-B1b were found in WW varieties. SW varieties carried alleles Glu-B1al, b, с and h. The average QS was higher in SW. Eight varieties had null alleles Glu-A1c, Glu-A3e, and Glu-B3j, which negatively affected bread-making quality.

Molecular Mechanism of Egg White Protein for Strengthening the Cross‐Linking Properties of Heat‐Induced Wheat Gluten Gel

AbstractThe chemical interaction between egg white protein (EWP) and wheat gluten (WG) is significantly influenced by the amount of EWP added. Therefore, the effects of EWP addition on the gelling properties and chemical interactions of heat‐induced WG–EWP gels are thoroughly examined. The results demonstrate that the enhancement in gel strength of WG–EWP gels is positively correlated with the amount of EWP added. EWP addition improves protein–protein interactions by reducing the freedom of water. The enhanced aggregation between WG and EWP is likely due to a decrease in surface hydrophobicity and an increase in β‐sheet content. EWP enhances cross‐linking with low molecular weight glutenin subunit (LMW‐GS), high molecular weight glutenin subunit (HMW‐GS), and gliadin (Gli). Specifically, EWP primarily cross‐links with ω‐, α‐, and γ‐Glis through S–S bonds and interacts with GS through hydrophobic interactions and S–S bonds. This study provides a theoretical foundation for improving the WG network structure in wheat‐based food production.

Identification and mechanism of wheat protein disulfide isomerase-promoted gluten network formation.

Formation of the gluten network depends on glutenin crosslinking via disulfide bonds, and wheat protein disulfide isomerase (wPDI) plays an important role in this process. Here, we identify a substrate gluten protein of wPDI and the mechanism underlying wPDI-promoted glutenin crosslinking. Farinographic, rheologic, and alveographic analysis unambiguously proves that wPDI improves gluten network formation, which is directly observed by 3D reconstruction of the gluten network. Protein analysis and LC-MS/MS reveal that glutenin subunit 1Dx5 is primarily recruited by wPDI to participate in gluten network formation, and its cysteine-containing N-terminal domain (1Dx5-NTD), which harbors three cysteine residues for crosslinking, is purified. 1Dx5-NTD interacts with wPDI in both redox states, possibly folded by reduced wPDI and then catalyzed by oxidized wPDI, as further evidenced by wPDI-promoted self-crosslinking. Consistent with macroscopic observations, our results suggest that wPDI folds 1Dx5-NTD into β-strand structure that favors disulfide bond formation.

The High-Molecular-Weight Glutenin Subunits of the T. timopheevii (AuAuGG) Group.

Polyploid wheats include a group of tetraploids known as Timopheevii (AuAuGG), which are represented by two subspecies: Triticum timopheevii ssp. timopheevii (cultivated) and Triticum timopheevii ssp. araraticum (wild). The combined use of electrophoretic (SDS-PAGE) and chromatographic (RP-HPLC) techniques carried out on high-molecular-weight glutenin subunits (HMW-GSs) permitted the association of different x- and y-type subunits to the A and G genomes and the assessment of allelic variation present at corresponding loci. The results also revealed that in both subspecies, accessions are present that possess expressed y-type subunits at the Glu-A1 locus. Genes corresponding to these subunits were amplified and amplicons corresponding to x- and y-type genes associated with the A genome were detected in all accessions, including those without expressed x- and y-type subunits. The comparison with genes of polyploid wheats confirmed the structural characteristics of typical y-type genes, with the presence of seven cysteine residues and with hexapeptide and nonapeptide repeat motifs. The identification of wild and cultivated T. timopheevii with both x- and y-type glutenin subunits at the Glu-A1 and Glu-G1 loci represents a useful source for the modification of the allelic composition of HMW-GSs in cultivated wheats with the ultimate objective of improving technological properties.

Grain albumin content is affected by 1BL/1RS translocation and alters the processing quality of wheat (Triticum aestivum L.).

Grain albumin is highly nutritious and closely related to the processing quality of wheat. However, few studies have explored the grain albumin content (GAC) in wheat. This study aims to uncover quantitative trait loci (QTLs) linked to wheat GAC by analyzing a doubled haploid (DH) population derived from common wheat cultivars ShanNong23 and ZhouMai17. We detected six QTLs controlling GAC on chromosomes 1B, 5A, and 6D, with individual QTL explaining 5.78% to 22.29% of the GAC variation. The effect of QGac.cau-1B.1 on GAC is attributed to the presence of the 1BL/1RS translocation, indicating that the 1BL/1RS translocation increase of GAC compared with the non-1BL/1RS translocation lines. The higher GAC observed in 1BL/1RS lines could be primarily attributed to the increased accumulation of omega-secalin, omega-gliadin, low molecular weight glutenin subunit and ribosomal protein content. Additionally, we also found that the SDS-sedimentation value of whole wheat flour was decreased by adding albumin solution. These results advance our understanding of the genetic basis of GAC and offer novel perspectives for enhancing wheat quality through genetic enhancements.

High‐molecular‐weight glutenin subunit profiles of eastern US soft winter wheat desirable for making soft‐bite white salted noodles

High‐molecular‐weight glutenin subunit profiles of eastern US soft winter wheat desirable for making soft‐bite white salted noodles

Image-assisted quantification of high and low molecular weight glutenin fractions in wheat by SDS-PAGE

Gluten quality in bread wheat is mainly determined by gluten strength and protein content. Traditionally gluten quality has been predicted based only on allelic variation for HMW-GS characterized by SDS-PAGE- The ratio of high to low molecular weight glutenin subunits has received less attention despite its influence on gluten properties is acknowledge. That is mainly because accurate quantification of glutenin fractions is made by RP-HPLC, a more complex, expensive and time-consuming technology. In the present study, a methodology to estimate HMW/LMW glutenin subunit ratio by SDS-PAGE results was assessed. We used a segregating population derived from a cross between two Spanish bread wheat landraces (Richela Blanca and Jeja Pardilla) showing striking differences according to SDSS tests. Quantification of prolamins by RP-HPLC confirmed a wide range of variation in the HMW/LMW glutenin subunit ratio within the population. Then, we selected 22 lines that represented the available variation. Subsequently, we obtained high-quality SDS-PAGE images following a standard protocol to characterize glutenin allelic variants. Estimation of HMW/LMW-GS ratio was obtained by analyzing the intensity of HMW-GS and LMW-GS gel bands. Correlation between RP-HPLC and SDS-PAGE values was greater than 0.85 proving the suitability of the much simpler and cheaper electrophoretic-based alternative.

Development of a germplasm master set covering variability of high molecular weight glutenin subunits for the GLU-A1 locus in Triticum sp.

Gluten quality is an important characteristic of wheat. Gluten is a viscoelastic protein network that is formed after hydrating and mixing wheat flour. This protein network is mainly composed of glutenins (High and Low Molecular Weight Glutenins (HMW-GS and LMW-GS, respectively)) and gliadins. HMW-GS are codified by the loci GLU-A1, GLU-B1 and GLU-D1 in common wheat. For the GLU-A1 locus, many alleles have been described and collected in the Wheat Gene Catalogue (WGC). Many of those alleles have not been compared in conjunction and it is not possible to know if the current GLU-A1 variability described is real or it is overestimated. This study has focused on collecting all the germplasm associated with GLU-A1 variability, to verify the GLU-A1 allele of each accession and if the current variability described in the WGC is real. It was possible to collect and compare by SDS-PAGE most of the germplasm described in the WGC. The identity of many alleles was confirmed while there are other cases that should be reviewed in more detail. This study contributes to the correct classification of the GLU-A1 diversity and will promote the use of different alleles in future breeding programs aiming to improve gluten quality.

Genetic basis of an elite wheat cultivar Guinong 29 with harmonious improvement between multiple diseases resistance and other comprehensive traits

Fungal diseases, such as powdery mildew and rusts, significantly affect the quality and yield of wheat. Pyramiding diverse types of resistance genes into cultivars represents the preferred strategy to combat these diseases. Moreover, achieving collaborative improvement between diseases resistance, abiotic stress, quality, and agronomic and yield traits is difficult in genetic breeding. In this study, the wheat cultivar, Guinong 29 (GN29), showed high resistance to powdery mildew and stripe rust at both seedling and adult plant stages, and was susceptible to leaf rust at the seedling stage but slow resistance at the adult-plant stage. Meanwhile, it has elite agronomic and yield traits, indicating promising coordination ability among multiple diseases resistance and other key breeding traits. To determine the genetic basis of these elite traits, GN29 was tested with 113 molecular markers for 98 genes associated with diseases resistance, stress tolerance, quality, and adaptability. The results indicated that two powdery mildew resistance (Pm) genes, Pm2 and Pm21, confirmed the outstanding resistance to powdery mildew through genetic analysis, marker detection, genomic in situ hybridization (GISH), non-denaturing fluorescence in situ hybridization (ND-FISH), and homology-based cloning; the stripe rust resistance (Yr) gene Yr26 and leaf rust resistance (Lr) genes Lr1 and Lr46 conferred the stripe rust and slow leaf rust resistance in GN29, respectively. Meanwhile, GN29 carries dwarfing genes Rht-B1b and Rht-D1a, vernalization genes vrn-A1, vrn-B1, vrn-D1, and vrn-B3, which were consistent with the phenotypic traits in dwarf characteristic and semi-winter property; carries genes Dreb1 and Ta-CRT for stress tolerance to drought, salinity, low temperature, and abscisic acid (ABA), suggesting that GN29 may also have elite stress-tolerance ability; and carries two low-molecular-weight glutenin subunit genes Glu-B3b and Glu-B3bef which contributed to high baking quality. This study not only elucidated the genetic basis of the elite traits in GN29 but also verified the capability for harmonious improvement in both multiple diseases resistance and other comprehensive traits, offering valuable information for breeding breakthrough-resistant cultivars.

Genetic Diversity of HMW-GS and the Correlation of Grain Quality Traits in Bread Wheat (Triticum aestivum L.) in Hubei Province, China

High-molecular-weight glutenin subunits (HMW-GS) are an important component of total cereal proteins in wheat. It is closely related to the processing quality of flour. Here, we analyzed allelic variations at the Glu-1 locus in 163 wheat accessions from Hubei Province, China with SDS-PAGE. Among the 15 alleles detected, alleles 1, 7+8, and 2+12 were the major alleles, and 7, 6+8, and 2+10 were rare alleles. The breeding lines had higher genetic diversity than the commercial varieties. Alleles 7 and 6+8 significantly reduced the grain protein content and wet gluten content of wheat. The “1, 7+9, 5+10” and “1, 14+15, and 2+12” allelic combinations significantly increased the grain protein content, hardness index, test weight, and wet gluten content of wheat. Alleles 7+9, 14+15, and 5+10 were identified as alleles related to high wheat quality. The “1, 7, 5+10”, “1, 6+8, 5+10”, “null, 7+9, 2+12”, “1, 14+15, 2+12”, and “1, 7+9, 5+10” allelic combinations had greater effects on wheat grain quality traits. These results demonstrate the effects of HMW-GS on wheat grain quality traits and provide a reference for the genetic improvement of wheat quality.

Development of PCR-based markers for identification of wheat HMW glutenin Glu-1Bx and Glu-1By alleles

BackgroundIn common wheat (Triticum aestivum L.), allelic variations in the high-molecular-weight glutenin subunits Glu-B1 locus have important effects on grain end-use quality. The Glu-B1 locus consists of two tightly linked genes encoding x- and y-type subunits that exhibit highly variable frequencies. However, studies on the discriminating markers of the alleles that have been reported are limited. Here, we developed 11 agarose gel-based PCR markers for detecting Glu-1Bx and Glu-1By alleles.ResultsBy integrating the newly developed markers with previously published PCR markers, nine Glu-1Bx locus alleles (Glu-1Bx6, Glu-1Bx7, Glu-1Bx7*, Glu-1Bx7OE, Glu-1Bx13, Glu-1Bx14(−), Glu-1Bx14(+)/Bx20, and Glu-1Bx17) and seven Glu-1By locus alleles (Glu-1By8, Glu-1By8*, Glu-1By9, Glu-1By15/By20, Glu-1By16, and Glu-1By18) were distinguished in 25 wheat cultivars. Glu-1Bx6, Glu-1Bx13, Glu-1Bx14(+)/Bx20, Glu-1By16, and Glu-1By18 were distinguished using the newly developed PCR markers. Additionally, the Glu-1Bx13 and Glu-1Bx14(+)/Bx20 were distinguished by insertions and deletions in their promoter regions. The Glu-1Bx6, Glu-1Bx7, Glu-1By9, Glu-1Bx14(−), and Glu-1By15/By20 alleles were distinguished by using insertions and deletions in the gene-coding region. Glu-1By13, Glu-1By16, and Glu-1By18 were dominantly identified in the gene-coding region. We also developed a marker to distinguish between the two Glu-1Bx14 alleles. However, the Glu-1Bx14(+) + Glu-1By15 and Glu-1Bx20 + Glu-1By20 allele combinations could not be distinguished using PCR markers. The high-molecular-weight glutenin subunits of wheat varieties were analyzed by ultra-performance liquid chromatography and sodium dodecyl sulfate–polyacrylamide gel electrophoresis, and the findings were compared with the results of PCR analysis.ConclusionsSeven Glu-1Bx and four Glu-1By allele detection markers were developed to detect nine Glu-1Bx and seven Glu-1By locus alleles, respectively. Integrating previously reported markers and 11 newly developed PCR markers improves allelic identification of the Glu-B1 locus and facilitates more effective analysis of Glu-B1 alleles molecular variations, which may improve the end-use quality of wheat.

RNA-Seq transcriptome profiling of immature grain wheat is a technique for understanding comparative modeling of baking quality

Improving the baking quality is a primary challenge in the wheat flour production value chain, as baking quality represents a crucial factor in determining its overall value. In the present study, we conducted a comparative RNA-Seq analysis on the high baking quality mutant “O-64.1.10” genotype and its low baking quality wild type "Omid" cultivar to recognize potential genes associated with bread quality. The cDNA libraries were constructed from immature grains that were 15 days post-anthesis, with an average of 16.24 and 18.97 million paired-end short-read sequences in the mutant and wild-type, respectively. A total number of 733 transcripts with differential expression were identified, 585 genes up-regulated and 188 genes down-regulated in the “O-64.1.10” genotype compared to the “Omid”. In addition, the families of HSF, bZIP, C2C2-Dof, B3-ARF, BES1, C3H, GRF, HB-HD-ZIP, PLATZ, MADS-MIKC, GARP-G2-like, NAC, OFP and TUB were appeared as the key transcription factors with specific expression in the “O-64.1.10” genotype. At the same time, pathways related to baking quality were identified through Kyoto Encyclopedia of Genes and Genomes. Collectively, we found that the endoplasmic network, metabolic pathways, secondary metabolite biosynthesis, hormone signaling pathway, B group vitamins, protein pathways, pathways associated with carbohydrate and fat metabolism, as well as the biosynthesis and metabolism of various amino acids, have a great deal of potential to play a significant role in the baking quality. Ultimately, the RNA-seq results were confirmed using quantitative Reverse Transcription PCR for some hub genes such as alpha-gliadin, low molecular weight glutenin subunit and terpene synthase (gibberellin) and as a resource for future study, 127 EST-SSR primers were generated using RNA-seq data.

Composition of high-molecular-weight glutenin subunits and gluten quality in wheat lines with alien genetic material

Background. High-molecular-weight glutenin subunits (HMW-GSs) make the greatest contribution to the formation of baking properties in bread wheat (Triticum aestivum L.). Glutenin polymorphism of bread wheat relatives is significantly richer than in cultivated varieties. The objective of this work was to identify the HMW-GS composition and assess the gluten quality of bread wheat lines with introgressions of alien genetic material.Materials and methods. We studied the parental varieties of spring bread wheat, accessions of the tetraploid and hexaploid Triticum L. species, and 19 introgressive lines produced with their participation. Glutenins were separated using sodium dodecyl sulfate polyacrylamide gel electrophoresis and HMW-GSs were identified using the Payne nomenclature system. Gluten quality was determined in accordance with GOST 13586.1-68 (the 2017–2019 and 2021–2022 growing seasons). Data processing was performed using the Statistica 10.0 and MS Excel software packages.Results and conclusion. HMW-GSs uncharacteristic of T. aestivum cultivars were identified in the studied accessions of T. dicoccoides (Körn. ex Aschers. et Graebn.) Schweinf., T. spelta L., and T. kiharae Dorof. et Migusch. These HMW-GSs are of interest for enriching the wheat gene pool. HMW-GSs of related species were found in 10 out of 19 introgressive lines. A five-year observation period revealed that wheat relatives on average significantly exceeded common wheat cultivars in gluten quality, and introgressive lines did not differ significantly from the parental genotypes. Lines with high rheological properties of gluten had, as a rule, HMW-GSs of related species in their composition.

The benefits of experimental breeding research genotypes for the genetic resources of spring durum wheat

AbstractOur study aimed to incorporate 60 newly acquired spring durum wheat genotypes into the Prague Gene Bank collection, focusing on 54 experimental breeding research genotypes and their technological quality contributions for conservation and future use. We analyzed a total of 11 field and 6 technological parameters of grain quality. Additionally, we identified the composition of high molecular weight glutenin subunits (HMW-GSs) in 13 accessions with contrasting technological characteristics. Two different extraction procedures were employed to detect HMW-GSs: one based on total protein extraction and the other on gliadin pre-extraction. The tested parameters exhibited a significant range of variability, with the relative standard deviation ranging from 2.1% for starch content to 96.7% for the gluten index. Additionally, six breeding research genotypes exhibited high technological grain quality comparable to the two modern durum wheat cultivars. Two accessions: M90-99–2 and IG 142076 showed above-average Zeleny sedimentation values, probably positively influenced by the presence of HMW-GSs A1: (2*). Genotypes PI 675012 and IG 142039 displayed the highest grain stability in technological parameters. Both extraction methods also detected the specific subunit B1: (6 + 8*) in the genotype IG 142039. Preserving these genotypes thus represents a substantial expansion of genetic resources in the genebank.

Rapid analysis of wheat gluten composition using a triple ELISA.

Gluten composition is an important quality parameter of wheat flour. Reversed-phase high-performance liquid chromatography (RP-HPLC) is a state-of-the-art method for its analysis. As this is a very labour-intensive and time-consuming procedure, alternative faster methods are desirable. Enzyme-linked immunosorbent assay (ELISA) is a high-throughput method often used for the analysis of gluten traces in gluten-free products. In this proof-of-principle study, we introduce an experimental triple ELISA for the relative quantitation of gliadins, high-molecular-weight glutenin subunits (HMW-GS) and low-molecular-weight glutenin subunits (LMW-GS) of one wheat flour extract. The results of 80 common wheat flour samples obtained from the triple ELISA and RP-HPLC were correlated. The results for gliadins (r = 0.69) and HMW-GS (r = 0.81) showed a medium and high correlation, respectively. Only a very weak correlation of ELISA and RP-HPLC results was observed for LMW-GS (r = 0.49). Results for glutenins (r = 0.69) and gluten (r = 0.72) had a medium correlation. The gliadin/glutenin ratio (r = 0.47) and LMW-GS/HMW-GS ratio (r = 0.40) showed a weak or no correlation. The gliadin, LMW-GS and gluten contents were lower and the HMW-GS content was higher in the ELISA measurement compared to RP-HPLC. The quantitation of gliadins and HMW-GS by the experimental triple ELISA showed comparable results to RP-HPLC, whereas no strong correlation between the results from the two methods was found for LMW-GS. Overall, the experimental triple ELISA is suitable for relative gluten quantitation, especially for the analysis of large sample sets. Further work will focus on improving the experimental procedure of the ELISA. © 2024 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Effect of Microwave Treatment on Protease Activity, Dough Properties and Protein Quality in Sprouted Wheat.

In this study, the effects of microwave treatment on protease activity, dough properties and protein quality in sprouted wheat were investigated. Microwave treatment led to a significant (p < 0.05) reduction in protease activity in sprouted wheat. Proteases with a pH optimum of 4.4 (cysteine proteinases) were more susceptible to microwave heating, which contributed mostly to protease inactivation. Significant improvements (p < 0.05) in the dough properties and gluten quality of sprouted wheat were observed, which are probably attributable to the synergistic effectiveness of protease inactivation and heat-induced gluten cross-linking. After microwave treatment, the decrease in the solubility and extractability of protein in sprouted wheat indicated protein polymerization, which was induced by intermolecular disulfide bond cross-linking. The changes in gliadin were less pronounced due to the relatively low temperature of the microwave treatment. The cross-linking in sprouted wheat that occurred after microwave treatment seemed to mainly involve glutenin, especially B/C low-molecular-weight glutenin subunits (B/C-LMW-GSs) in the range of 30-50 kD.

Manipulation of the post-flowering source/sink ratio differentially affects protein composition and gluten quality in contrasting bread wheat genotypes

Studies of the impact of assimilate availability during grain filling on protein composition and gluten quality of bread wheat are scarce. Therefore, this work aimed to analyze the responses of wet gluten percentage, SDS sedimentation index, and protein composition to changes in the source/sink (S/S) ratio (post-flowering growth per grain) in six Argentinean wheat genotypes contrasting in baking aptitude (three quality groups), as well as to evaluate its interaction with early nitrogen-sulfur fertilization. For two years, rainfed field trials were carried out in the Humid Pampas in Southern South America, applying manipulative S/S treatments (shading, defoliation, thinning, and trimming). Gluten percentage showed a negative linear trend against the increase in S/S ratio with differences among genotypes even within the same quality group (slope range: −0.0248 to −0.6566). The associations between the main protein fractions (i.e., GLI/GLU, HMW/LMW) with the S/S ratio were not significant, while the proportions of specific high molecular weight glutenin subunits were relevant, such as Glu-A1x/HMW (slope range: −0.00027 to −0.00147) and Glu-D1y/HMW (0.00029–0.00139). Early nitrogen-sulfur fertilization increased the influence of the S/S ratio on gluten percentage while stabilizing the sedimentation index. These results apport another approach, based on S/S ratio, to understanding the determination of grain quality under changing contexts.