Gluten Proteins Research Articles

Effect of fluorescence dyes on wet gluten structure studied with fluorescence and FT-Raman spectroscopies

Fluorescence spectroscopy coupled with FT-Raman spectroscopy were used to determine effect of two fluorescent dyes (fluorescein and rhodamine B) on the structure of wet gluten (hydrated gluten). Additionally, PCA analysis was applied to find correlations between fluorescence and Raman parameters. The fluorescent dyes, regarded as model representatives of phenolic compounds, were added to model dough in six concentrations (0.05%–0.5%). Wet gluten samples and starch slurries (as a residue after washing out gluten) were excited by two wavelengths – one assigned to tryptophan, and the second to the particular dye. Fluorescence and UV-VIS analysis of starch slurries show that the dyes can be completely bound to gluten proteins because of their absence in the slurries. Analysis of the spectroscopic results indicate that fluorescein and rhodamine B interact with gluten proteins in different ways depending on the type of functional groups present in the dye structure. The fluorescein molecules, due to the presence of hydroxyl and carboxyl groups may incorporate into gluten network by forming hydrogen and/or covalent bonds, whereas rhodamine B with four methyl groups may be enclosed in hydrophobic pockets formed by gluten polypeptide chains. These differences can be related to the type of functional groups present in the dye structure (fluorescein has one hydroxyl group, rhodamine B has four methyl groups). PCA analysis showed correlations between dye fluorescent parameters (maximum wavelength and band intensity) and some structural parameters (presence or absence of bands assigned to α-helices, β-turns and S S bonds conformations). The PCA results also suggest that mechanism of interactions gluten – dye depends on type of functional groups present in the dye molecule. • Interactions between gluten and dyes depend on functional groups present in dye. • Fluorescein with hydroxyl and carboxyl groups can incorporate into gluten network. • Rhodamine B with four methyl groups may be enclosed in hydrophobic pockets. • Structural changes observed in gluten network depend on the dye concentration. • Fluorescence spectra of TRP may indicate type of gluten-polyphenols interactions.

S3390 Celiac Disease and Systemic Eosinophilia: A Case Report

Introduction: Celiac disease is an immune mediated reaction to the gluten protein. this disease primarily affects the small intestine.it occurs in population with genetic predisposition, usually resolves with gluten free diet regimen. it was reported the association between eosinophilic gastrointestinal diseases and celiac disease but in the following case will discuss patient with significant peripheral eosinophilia and celiac disease without Eosinophilic gastrointestinal disorder. Case Description/Methods: 45 years old male, with history of hypertension, who presented with progressively worsening intermittent colicky lower abdominal pain for the past 2 months. Associated with recurrent episodes of nausea and vomiting, and non-bloody watery diarrhea.Patient Labs were significant for Hemoglobin 12 gm/dL, WBC’s 26,000 with 62% Eosinophils (16,500 /uL), Platelet of 332 Thou/uL. Peripheral blood smear was negative for parasites, stool was negative for parasites or bacterial infection. Patient went upper GI endoscopy that showed grade A reflux esophagitis, congestive gastropathy, Duodenitis, and non-bleeding gastric ulcer, Biopsies were obtained during the EGD. Pathology showed Duodenal mucosa with mild villous atrophy and focal increased intraepithelial lymphocytes suggestive of celiac disease,chronic gastritis, esophageal biopsy was negative for increased eosinophils. Patient was started on gluten free diet that was resulted in gradual resolution of his symptoms and also normal eosinophilic count after 1 month. (Figure) Discussion: Patient with celiac disease can present with typical gastrointestinal symptoms such as diarrhea, weight loss, bloating, abdominal pain, and also non-gastrointestinal abnormalities such as abnormal liver function test, iron deficiency anemia, and it may be asymptomatic. In this case patient presented with typical symptoms but was associated with significant peripheral eosinophilia, without evidence eosinophilic gastrointestinal disorder.Figure 1.: EGD showing stomach and duodenum.

INFLUENCE OF THE SYSTEMATIC APPLICATION OF FERTILIZERS ON THE INTENSITY OF ACCUMULATION OF NITRATES IN AGRICULTURAL CROPS

This article examines the problems of climate change and the impact of fertilizers on the productivity and quality of winter wheat. As a result of research, it has been established that in recent decades the world has undergone significant climate change, which causes serious problems in the development of agriculture. The results of research show that the yield of winter wheat, which is obtained due to the potential fertility of soils, on average for 3 years was 2,5 t/ha. Systematic application of the fertilizers in crop rotation helped to increase the yield of winter wheat. After the treatment N60P60K60 the additions in 1,0 t/ha to the control have been received. On the plots where winter wheat was tested the aftereffect of manure 30 t/ha in combination with N60P60K60 increases the yield on 1,0 and 1,3 t/ha respectively. The highest yield of winter wheat obtained by application of mineral fertilizers in quantity N120P120K120 was 3,7 t/ha. On the control option the average protein content was 12,13. The record amount of protein observed after N120P120K120 application was 13,28. It should be noted that the quality of the gluten protein content and the winter wheat grain in all these tests is significantly higher compared with controls. The average gluten content in the control test was 20,3, while during the fertilizer using it varied in the range of 23,5–27,3. The highest protein was observed after N120P120K120 application 27,3. Besides that, the nitrate content in the grain and plants of winter wheat after different doses of mineral and organic fertilizers have been examined. It should be noted that the nitrate content in winter wheat grain is independent from the fertilizer and varied from 44,0 to 50,0 mg/kg, in the straw this dependence has been slightly observed. So if the control has 128,6 mg/kg nitrate content, in the fertilized tests it varied from 128,6 to 155,0 mg/kg. Maximum nitrate content was on the plot after the minimum N60P60K60 application and manure usage at 30 t/ha. Comparative study of the influence of mineral and organic fertilizers, as well as their combinations showed that after the application of organic fertilizer fewer nitrates accumulates in plants than after mineral and organic-mineral.

Black rice flour‐induced changes in gluten conformation in fresh, pre‐fermented and frozen dough

SummaryBlack rice flour greatly enriches the nutrition of flour products, and also alleviates the quality deterioration of frozen dough to a certain extent, but the gluten‐influenced mechanism remains unclear. The effects of black rice flour with different particle sizes on protein molecular weight distribution, secondary structure, fluorescence characteristics, thermogravimetric properties, and chemical interaction of the fresh dough (FD), pre‐fermented dough (PD), and thawed dough (TD) were investigated. The addition of black rice flour resulted in the breaking of disulfide bonds in the FD and an increase in the content of total SDS‐extractable protein. However, the depolymerization of large glutenin polymers in the PD and TD of the composite flour system was lower than wheat flour system, especially in the dough with small particle size black rice flour. As the particle size of black rice flour decreased, the intermolecular force of the composite flour dough system is more prominent, of which the hydrophobic interaction force contributes the most considerable value. In addition, TD in the composite flour system has less weight loss than that of wheat flour system. Therefore, adding black rice flour reduced the deterioration of gluten protein, and the small particle size of black rice flour showed advantages.

Characterization of sonicated gluten protein and subsequent rheological properties of model dough and noodles.

The present study aimed to investigate the effects of the thermo-mechanical and rheological properties of a wheat gluten-sonicated model dough and noodles, as well as the effects of ultrasonic frequency (20, 28, 40, 68 and 80 kHz) on the functional properties and structural features of gluten. Water absorption, stability and developmental time, and viscoelastic behavior of gluten-sonicated model dough were all found to be improved. Water absorption, tensile resistance and stretching distance of noodles increased markedly, whereas cooking loss decreased. Ultrasonication at different frequencies also significantly affected gluten structure, including its surface hydrophobicity, micro-network structure, and secondary and tertiary structures. These alterations then caused changes in its functional characteristics. Compared to untreated gluten, sonicated gluten exhibited significantly increased oil and water capacities (8.75-15.26% and 100.65-127.71% higher than the untreated gluten, respectively), foaming and emulsifying properties, and increased solubility (63.46-98.83% higher than control). In addition, these findings indicated that 40 kHz was the likely resonance frequency of the cavitation bubble in the gluten solution. However, sodium dodecyl sulfate-polyacrylamide gel electrophoresis electropherograms revealed that such treatments did not affect the molecular weight of gluten, which was also consistent with its unchanged disulfide bond content. The present study clarified the impact of frequency on the properties of gluten and model dough. The best frequency for modification of gluten was 40 kHz. Collectively, these findings suggest that ultrasonic technology has the potential for use in modifying wheat gluten and commercial noodle processing. © 2022 Society of Chemical Industry.

Research on the Properties of Zein, Soy Protein Isolate, and Wheat Gluten Protein-Based Films Containing Cellulose Nanocrystals.

Plant protein films are a research hotpot in the current food packaging field for their renewable and bio-compatibility, and further improving the physicochemical properties of plant protein films in combination with biodegradable materials is of great significance. In this study, we selected cellulose nanocrystals (CNC) to modify the protein films with soybean protein isolate (SPI), wheat gluten protein (WGP), and Zein, and the physicochemical properties were studied. The results showed that the hardness and opacity of Zein-based films decreased by 16.61% and 54.12% with the incorporation of CNC, respectively. The SPI-based films performed with lower hardness and higher tensile strength. The thickness and opacity of WGP-based films increased by 39.76% and 214.38% after combination with CNC, respectively. Accordingly, this study showed that CNC could largely modify the physicochemical properties of the plant protein films, which provided a reference for the preparation of modified plant protein films using biodegradable materials.

Role of tryptophan content in determining gluten quality and wheat grain characteristics

Gluten protein makes 75–80% of the wheat protein and is of utmost importance because of its unique visco-elastic properties which have significant role in development of various food products especially the baked ones. The quality of gluten protein is determined by its subunit (glutenin and gliadin) number and composition. To determine the effect of amino acid tryptophan on gluten strength and other quality parameters, a set of 34 bread wheat genotypes consisting of 19 lines and 15 checks were estimated in the present study. As per the results obtained in this study, tryptophan, although present in low amounts in gluten, accorded positively with gluten strength. The study also highlights the relation between wheat grain protein, gluten strength and tryptophan content.

Safety Assessment of Foods and Drinks Consumed by People on a Gluten-Free Diet.

Naturally gluten-free foods and processed foods that do not contain information about the potential presence of gluten in them pose a hypothetical threat to people with food allergies and celiac disease. Patients who should follow a strict gluten-free diet do not always do so. Therefore, the aim of this research was to analyze certified “gluten-free” and naturally gluten-free products without labeled “may contain gluten” information in terms of their content of gluten proteins. The enzyme immunoassay AgraQuant Gluten G12 ELISA test kit was used for the analysis. Of all the products used in the research, only 5.8% were found to contain gluten above 20 ppm. Only one product labeled “gluten-free” was contaminated with gluten at 79.3 ppm (cider cake). In addition, our research also examined the gluten content of commercial beers containing barley malt not labeled as “gluten-free”. Research has shown that 60% of samples are not safe for those on a strict gluten-free diet. Our research clearly shows that many manufacturers, although they do not monitor their products for the presence of gluten in them, offer safe products, although they cannot be recommended in a gluten-free diet. Therefore, there is a strong need to increase the frequency of testing by food manufacturers for the presence of gluten in their products, so that the number of products approved for people on a gluten-free diet continues to increase.

Effect of wheat bran dietary fiber on structural properties and hydrolysis behavior of gluten after synergistic fermentation of Lactobacillus plantarum and Saccharomyces cerevisiae.

The effect of synergistic fermentation of Lactobacillus plantarum and Saccharomyces cerevisiae on the structural properties and aggregation behavior of gluten containing different wheat bran dietary fiber (WBDF) levels (0, 3, 6, 9, and 12%) was investigated. The results showed that WBDF addition affected the aggregation behavior of gluten at the molecular level, while WBDF significantly induced depolymerization behaviors in large aggregated gluten proteins (Molecular weight > 130 kDa) under reducing conditions (p < 0.05). In terms of secondary structure, WBDF significantly reduced glutamine side chain levels and reduced antiparallel β-sheet structures from 28.57 to 24.53% (p < 0.05). In addition, WBDF thermal properties and its water holding capacity were the main factors causing changes in thermal properties in the overall gluten system. This study provides new data for the improved production of sourdough whole grain and/or high fiber flour products.

Effects of addition of inulin and β‐glucan on selected physicochemical and thermal properties of ultrasonic modified potato flour

Potato flour has poor processing performance because of gluten free status. The study investigates the effect of the addition of inulin and β-glucan on the process qualities of ultrasonic modified potato flour. Inulin or β-glucan was added respectively in five amounts of 0.1% – 0.5% according to a step of 0.1%. The doughs with inulin or β-glucan were more compact and had a more uniform micromorphology. The thermal properties and the water-holding capacity were all significantly increased particularly at the adding amount of 0.3%. The FTIR spectra showed that inulin and β-glucan were associated with potato flour through hydrogen bonds, which maintained the stability of the structure, and did not differ either between the two types of polysaccharides, or the amount of inulin and β-glucan added. This study provides some theoretical stepstones to improve the processing quality of potato flour by mitigating the disadvantages attributable to being gluten free. Novelty impact statement The present investigation revealed that the addition of inulin or β-glucan following ultrasonic treatment can overcome the disadvantages associated with the loose structure of potato flour caused by a lack of gluten protein, beneficial for either actual or potential use for gluten free food development. The study demonstrated that both inulin and β-glucan can improve the processing quality of ultrasonicated potato flour especially with the amount of 0.3% of inulin or β-glucan by mitigating the disadvantages attributable to the lack of gluten.

Aggregation properties and structure of chia seed gum and gluten protein mixtures after freezing storage

Chia seed gum (CSG) plays an important role in the aggregation and structural properties of gluten protein. The experimental results showed that adding 1.0 % CSG increased the freezing rate and shortened the freezing time by 42.3 % compared with gluten without CSG. At the same time, CSG had no significant effect on the composition of the gluten subunit but could better control the change in binding water and delay the structural deterioration caused by the extension of time (30 d). The viscoelasticity of gluten was increased, but only with the addition of 0.2–0.6 % CSG. In addition, it increased the denaturation transition temperature (Tp) and the degradation temperature (Td) of gluten protein to reduce the occurrence of recrystallization and resist pyrolysis. During frozen storage, gluten can form fine ice crystals and inhibit the transformation of α-helices and β-turns to random coils and β-sheets, which is more conducive to long-term frozen storage.

Evolution of the morphological, structural, and molecular properties of gluten protein in dough with different hydration levels during mixing.

To understand the formation process of dough with different hydration levels upon mixing and the response of dough rheology, the dynamic evolution of gluten protein was tracked and quantified at morphological, structural, and molecular levels. Both macroscopical and microscopic distribution images showed that partial and full hydration induced quick formation of a more compact gluten network compared with limited hydration. Gluten network in highly hydrated samples was more susceptible to the formation and collapse induced by mechanical force. SE-HPLC results indicated significant depolymerization of glutenin macropolymer (GMP) in fully and partially hydrated samples. Sufficient mixing was accompanied by the increase of ionic and hydrogen bonds, while excessive mixing increased exposure of free -SH. Higher hydration level induced more ordered secondary structure. Correlation and principal component analysis revealed the patterns and dynamics of gluten evolution during dough formation with different hydration levels, and their contribution to the changes in dough modulus.

Effect of Auricularia auricula polysaccharide on characteristic structure, rheological properties, and tensile texture in whole wheat dough

In this study, the effects of Auricularia auricula polysaccharide (Aap) on the quality of whole wheat dough (WWD) were investigated. The results showed that compared to the control, the content of ordered structure (β-sheet) of gluten protein improved by 6.81% and the content of free sulfhydryl decreased by 63.73% respectively in WWD with 1% Aap. Furthermore, the content of immobilized water increased up to 94.89% and the moisture distributed in the center of the dough had higher fluidity in WWD with 1% Aap. Moreover, the rheological properties of WWD including storage modulus and loss modulus were significantly increased with the addition of Aap compared to the control. In addition, the tensile resistance and the stretching distance of the WWD with 1% Aap improved by 68.01% and 12.65% respectively. Therefore, 1% Aap significantly improved the quality of WWD by affecting moisture, starch, and protein fractions in the dough. Novelty impact statement In this paper, it was found that Aap could significantly improve the quality of WWD, solving the problems of poor viscoelasticity and low quality of WWD. The application of Aap on WWD provided a theoretical basis and research ideas for the development of high-quality whole wheat food.

Sulfur uptake and distribution, grain yield, and quality of hybrid and inbred winter wheat (Triticum aestivum L.) varieties under early and late waterlogging

AbstractBackgroundWaterlogging at early and later growth stages could affect sulfur (S) uptake, distribution, yield, and quality of winter wheat. We hypothesized that the hybrid winter wheat variety (Hyvento), with a high degree of heterosis and genetic diversity, is likely to uptake and utilize S more efficiently and withstands waterlogging better than the inbred wheat variety (Kredo).AimsThe objective of the present study was to investigate the effect of 2‐week waterlogging at the end of tillering stage (Feekes Stage 6) and/or ear emergence stage (Feekes Stage 10.1) on grain yield, yield components, S‐uptake and its partitioning, and composition of grain storage proteins (glutenins and gliadins) of hybrid (Hyvento) and inbred (Kredo) winter wheat varieties.MethodsPlants were grown in large containers (120 L) in a semi‐controlled greenhouse and harvested three times immediately after each waterlogging treatment and at agronomic maturity. Grain yield, S concentration in different plant organs, total protein content, and patterns of gluten proteins (gliadin and glutenin) and their subunits (by sodium dodecyl sulfate–polyacrylamide gel electrophoresis) in grains were evaluated.ResultsGrain yield of the inbred variety was more negatively affected under early and late waterlogging than the hybrid variety and was associated with reduced grain size. The decline in grain yield was significantly higher under late waterlogging (30%–31%) than early waterlogging (17%–18%). Compared to the hybrid variety Hyvento, the waterlogging‐induced decline in S concentration in grains, husk, and straw was markedly lower in the inbred variety Kredo. While early waterlogging did not affect total grain protein content in either of the varieties, late waterlogging significantly reduced the total grain protein content (18%) in the inbred variety Kredo. Similarly, the grain gliadin content of the hybrid variety was not affected by both waterlogged conditions, whereas 32% and 23% reductions were recorded for the inbred variety under early and late waterlogging, respectively. Nevertheless, waterlogging significantly increased the proportion of S‐poor high‐molecular‐weight glutenin subunits and ω‐gliadin in the inbred variety.ConclusionIt could be inferred from the present study that hybrid winter wheat variety is relatively resistant to waterlogging than the inbred wheat variety, and thereby produces higher grain yield. Efficient uptake and metabolism of S could be one of the mechanisms conferring waterlogging resistance in winter wheat.

Drought and heat stress effects on gluten protein composition and its relation to bread-making quality in wheat

Wheat grain proteins are largely affected by environmental conditions, with drought and heat stress causing considerable changes to gluten composition, resulting in variations in bread-making quality. Size-exclusion high-performance liquid chromatography (SE-HPLC) was used to assess the effects of moderate and severe drought and heat stress on variation in gluten proteins in bread wheat cultivars. Extractable gliadin (exGLi), mixing time (MixT) and total polymeric proteins (TPP) were largely genetically determined, while flour protein content (FPC) and extractable albumins/globulins (exAG) were significantly affected by treatment. The two levels of both heat and drought stress caused differential expression of gluten proteins. The unextractable polymeric proteins were reduced under severe heat stress, while both extractable and unextractable low molecular weight glutenin fractions were increased, leading to a weakening of the dough and deterioration of quality. Severe drought caused increased values of all bread-making related characteristics and loaf volume (LV), coupled with significant increases in unextractable polymeric and monomeric proteins and exGLi. Moderate heat stress caused increases in extractable HMW glutenin, which negatively affected bread-making characteristics. The large and total polymeric proteins were consistently correlated with LV for all treatments, although extractable HMW glutenins were generally negatively correlated with baking characteristics under all treatments.

High-Moisture Shear Processes: Molecular Changes of Wheat Gluten and Potential Plant-Based Proteins for Its Replacement.

Nowadays, a growing offering of plant-based meat alternatives is available in the food market. Technologically, these products are produced through high-moisture shear technology. Process settings and material composition have a significant impact on the physicochemical characteristics of the final products. Throughout the process, the unfolded protein chains may be reduced, or associate in larger structures, creating rearrangement and cross-linking during the cooling stage. Generally, soy and pea proteins are the most used ingredients in plant-based meat analogues. Nevertheless, these proteins have shown poorer results with respect to the typical fibrousness and juiciness found in real meat. To address this limitation, wheat gluten is often incorporated into the formulations. This literature review highlights the key role of wheat gluten in creating products with higher anisotropy. The generation of new disulfide bonds after the addition of wheat gluten is critical to achieve the sought-after fibrous texture, whereas its incompatibility with the other protein phase present in the system is critical for the structuring process. However, allergenicity problems related to wheat gluten require alternatives, hence an evaluation of underutilized plant-based proteins has been carried out to identify those that potentially can imitate wheat gluten behavior during high-moisture shear processing.

The Immunobiology and Pathogenesis of Celiac Disease.

Among human leukocyte antigen (HLA)-associated disorders, celiac disease has an immunopathogenesis that is particularly well understood. The condition is characterized by hypersensitivity to cereal gluten proteins, and the disease lesion is localized in the gut. Still, the diagnosis can be made by detection of highly disease-specific autoantibodies to transglutaminase 2 in the blood. We now have mechanistic insights into how the disease-predisposing HLA-DQ molecules, via presentation of posttranslationally modified gluten peptides, are connected to the generation of these autoantibodies. This review presents our current understanding of the immunobiology of this common disorder that is positioned in the border zone between food hypersensitivity and autoimmunity.

Are Patients With Celiac Disease at Greater Risk of Craniomaxillofacial Fractures?

Celiac disease (CD) is a chronic gastrointestinal disorder characterized by an immune reaction to gliadin, a component of the gluten protein found in wheat and other cereal grains. It primarily affects the small intestine, leading to the classic symptoms of diarrhea, abdominal pain, bloating, weight loss, and fatigue. Chronic malabsorption and inflammation within the intestine also contribute to extra-intestinal manifestations of the disease, including osteopenia and osteoporosis.1,2 There have been no studies investigating the risk of craniomaxillofacial fractures (CMF) in individuals with CD.

Research on a prolonged release system of urea powder potentially applied in sustainable agriculture

&lt;p&gt;A prolonged release system (SLIP) of urea powder encapsulated in a wheat gluten matrix was investigated as a sustainable substitute for use in agriculture with the goal of lowering nitrogen losses in the soil. Thermogravimetry (TGA), Fourier Transform Infrared Spectroscopy (FT-IR), and Scanning Electron Microscopy (SEM) were the methods used to characterize SLIP. The urea release kinetics in water were then assessed. Very porous structures were produced, the thermal stability of SLIP was noted, and interactions between urea and gluten proteins through hydrogen bonds were verified. According to the kinetics, urea was released at a high rate (38%) in the first ten minutes and reached the diffusion equilibrium (86.35%) after 36 hours. There is a chance that urea SLIP will be employed as a sustainable substitute in agriculture.&lt;/p&gt;

Study on moisture migration mechanism of dough during subfreezing storage

AbstractBackground and ObjectivesThe objective of this study was to investigate the effects of subfreezing storage on gluten protein denaturation and water retention. On this basis, the surface hydrophobicity, secondary structure, thermal stability, microstructure, and moisture distribution of gluten protein were measured.FindingsThe results showed that at the end of storage, the hydrophobicity indexes of wheat gluten proteins (−9°C and −12°C) stored under subfreezing conditions were significantly lower than those stored at 4°C and slightly lower than those stored at −18°C. The secondary structure stability of wheat gluten stored at −18°C was similar. P21 stored at −18°C was significantly higher than those stored at 4°C and showed an upward trend. The quality of the dough was similar to those stored at −18°C.ConclusionsThe deformation and water retention of gluten during subfreezing storage are similar to those stored at −18°C.Significance and NoveltyThe changes in dough moisture and gluten protein structure during frozen storage at different freezing temperatures were explored to provide a theoretical basis for the application of subfrozen storage in the frozen flour products industry.