Search

Inflammation and oxidative stress are two mechanisms involved in the pathogenesis of celiac disease (CD). Since the direct effect of gliadin on the intestinal epithelia is less studied, the aims of this study were the development of a specific cellular model based on the use of gliadin as a pro-inflammatory stimulus and the evaluation of the potential antioxidant and anti-inflammatory properties of extracts from different black rice in the framework of CD. The rice extracts were in vitro digested, characterized in terms of phenolic compounds and antioxidant capacity, and tested on Caco-2 cells to investigate their inhibitory effect on Reactive Oxygen Species, the NF-κB transcription and the CXC chemokines (sICAM-1, IL-8, and CXCL-10). In addition, the role of the extracts in modulating the activation of epithelial cells in CD was confirmed by applying the K562(S) agglutination test. The black rice extracts showed inhibitory effects on the production of the oxidative and the inflammatory mediators considered, with particular reference to lymphocyte-attracting CXCL-10 both before and after digestion. The presence of anthocyanins and their digestion metabolites may account for the observed anti-inflammatory activity after in vitro digestion. This work provided preliminary data supporting the use of black rice as a healthy food or ingredient of food supplements for celiacs.

Background and objectives: Determination of different grain protein fractions in wheat cultivars is an important task in analyzing bread baking quality. In many laboratories, the Bradford assay is used to determine protein concentrations in solutions. In any protein assay (including Bradford), the ideal protein to use as a standard is the purified protein being assayed. In the absence of such an absolute reference, protein another protein must be selected as a relative standard such as bovine serum albumin (BSA) which is widely used. The aim of this work was to find conversion factors for BSA to determine correct albumin–globulin, gliadin, and glutenin concentrations, because these purified wheat grain protein fractions are mostly not available to be used for calibration purposes. Findings: In case of BSA calibration, gluten concentration was underestimated (50%–54%) compared to calibration with the respective purified wheat proteins (65%–70%) in extracts of wheat grain samples. This result is explained with the different amino acid composition of BSA and wheat protein fractions leading to a more intense signal with BSA in the Bradford assay. Calibration of the Bradford assay using BSA as well as purified wheat protein fractions allowed to calculate the conversion factors of 2.11 for BSA/albumin–globulin, 4.25 for BSA/gliadin, and 3.42 for BSA/glutenin. Application of these conversion factors proved to accurately adjust protein concentrations of wheat fractions originating from ten cultivars, determined with BSA calibration of the Bradford assay. Conclusions: BSA calibration of the Bradford assay in combination with the conversion factors can be used to determine protein concentration of wheat grain fractions. Significance and novelty: Findings of this study make a contribution toward the correction of a common method, to provide a basis for better comparability of research results from different laboratories. [ABSTRACT FROM AUTHOR]

While individuals diagnosed with autism spectrum disorders (ASD) have higher levels of antibodies directed towards gliadin, a component of wheat gluten, no study has examined anti‐gliadin antibodies (AGA) in etiologically relevant periods before diagnosis. The objective of this study was to investigate if maternal levels of AGA, during pregnancy and at the time of birth, are associated with ASD in offspring. We analyzed AGA in archived neonatal dried blood spots (NDBS) for 921 ASD cases and 1090 controls, and in paired maternal sera collected earlier in pregnancy for a subset of 547 cases and 428 controls. We examined associations with ASD diagnoses as a group and considering common comorbidities (intellectual disability [ID] and attention‐deficit/hyperactivity disorder). We compared 206 cases to their unaffected siblings to examine the potential for confounding by shared familial factors. Odds of ASD tended to be lower among those with the highest levels (≥90th percentile) of AGA compared to those with low levels (<80th percentile; OR 0.78, 95% CI 0.56–1.09, measured in NDBS). This pattern was more apparent for ASD with comorbid ID when measured in NDBS (0.51, 0.30–0.87), with a similar trend in maternal sera (0.55, 0.24–1.29). High levels of AGA were similarly associated with lower odds of ASD in the sibling comparison. In summary, we found little association between maternal antibodies raised against components of gluten and risk of ASD in general. Exposure to high levels of AGA in the pre‐ and perinatal periods may be protective in terms of risk for ASD with ID. Lay Summary: There is a debate among both scientists and community members as to whether an immune reaction to gluten exposure could be considered a cause of autism. We examined antibodies that are directed against gliadin, a part of gluten, in samples collected from pregnant mothers and their newborn babies. We did not see any major differences in the antibody level among those children diagnosed with ASD or their mothers compared to children who were not diagnosed with ASD. High levels of the antibodies were in fact associated with a somewhat lower risk of ASD with co‐occurring intellectual disabilities, though we cannot tell from this study why that might be the case. Lay Summary: There is a debate among both scientists and community members as to whether an immune reaction to gluten exposure could be considered a cause of autism. We examined antibodies that are directed against gliadin, a part of gluten, in samples collected from pregnant mothers and their newborn babies. We did not see any major differences in the antibody level among those children diagnosed with ASD or their mothers compared to children who were not diagnosed with ASD. High levels of the antibodies were in fact associated with a somewhat lower risk of ASD with co‐occurring intellectual disabilities, though we cannot tell from this study why that might be the case. [ABSTRACT FROM AUTHOR]

Copyright of Food & Machinery is the property of Food & Machinery Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Food Research & Development is the property of Food Research & Development Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Celiac disease (CeD) is a T-cell-dependent enteropathy with autoimmune features where tissue transglutaminase (TG2)-mediated posttranslational modification of gliadin peptides has a decisive role in the pathomechanism. The humoral immune response is reported to target mainly TG2-deamidated γ-gliadin peptides. However, α-gliadin peptides, like p57-68, playing a crucial role in the T-cell response, and p31-43, a major trigger of innate responses, also contain B-cell gliadin epitopes and γ-gliadin like motifs. We aimed to identify if there are anti-gliadin-specific antibodies in CeD patients targeting the p31-43 and p57-68 peptides and to examine whether deamidation of these peptides could increase their antigenicity. We explored TG2-mediated deamidation of the p31-43 and p57-68 peptides, and investigated serum antibody reactivity toward the native and deamidated α and γ-gliadin peptides in children with confirmed CeD and in prospectively followed infants at increased risk for developing CeD. We affinity-purified antibody populations utilizing different single peptide gliadin antigens and tested their binding preferences for cross-reactivity in real-time interaction assays based on bio-layer interferometry. Our results demonstrate that there is serum reactivity toward p31-43 and p57-68 peptides, which is due to cross-reactive γ-gliadin specific antibodies. These γ-gliadin specific antibodies represent the first appearing antibody population in infancy and they dominate the serum reactivity of CeD patients even later on and without preference for deamidation. However, for the homologous epitope sequences in α-gliadins shorter than the core QPEQPFP heptapeptide, deamidation facilitates antibody recognition. These findings reveal the presence of cross-reactive antibodies in CeD patients recognizing the disease-relevant α-gliadins. [ABSTRACT FROM AUTHOR]

Copyright of Food & Machinery is the property of Food & Machinery Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The present study evaluated an enzyme strategy for eliminating the gliadin in the flour in order to produce part-baked (PB) frozen bread for celiac patients. At first, tissue transglutaminase with lysine methyl ester transamidated the gliadin and hydrolyses gliadin protein. The deamidated dough was used for producing the PB bread and then stored as the frozen storage at – 18 °C for 15 days, followed by investigating physicochemical, rheological, and sensory properties. The SDS-PAGE result demonstrated that transamidating wheat flour with a tissue transglutaminase and L-lysine methyl ester break down the gliadin protein. The PB frozen bread with the absence of gliadin had lower specific volume, porosity, firmness, and color index (P < 0.05) but adding 0.8% guar gum could improve these factors and recompense the absence of gliadin (P < 0.05). The PB frozen bread with 0.8% guar gum had physicochemical properties such as fresh bread which produced with untreated wheat flour (P < 0.05). [ABSTRACT FROM AUTHOR]

FT-Raman spectroscopy was applied to study interactions between wheat gliadins and three flavonoids and their glycosides. Complexes gliadins-flavonoids/glycosides were extracted from the model wheat dough. As flavonoids were used quercetin, naringenin, hesperetin and their glycosides rutin, naringin, hesperidin in the amount of 0.05%, 0.1% and 0.2%. The analysis of the FT-Raman spectra showed that the tested compounds caused changes in the secondary and tertiary structure of gliadins. In the case of gliadins, these changes concerned mainly α-helices. Quercetin induced a different type of structural changes compared to naringenin and hesperetin, which was probably due to the presence of a double bond on the C ring and an additional OH group on the B ring in the structure of this molecule. On the other hand, the interactions of glycosides with gliadins were affected by the place of attachment of the sugar part in the structure of the glycoside. Flavonoids/glycosides significantly increased the content of disulfide bridges in the g-g-g conformation. Changes in the amino acid microenvironment (tyrosine and tryptophan) indicate the formation of a more ordered structure in gliadins. [Display omitted] • Flavonoids and their glycosides caused changes in the structure of gliadins. • Quercetin induced a different type of structural changes compared to other flavonoids. • The added flavonoids/glycosides significantly changed the conformation of SS bonds. • Quercetin caused the greatest changes in the tyrosine environment. [ABSTRACT FROM AUTHOR]

The structure and functional properties of wheat gluten have fascinated cereal chemists for over a century and a range of approaches have been taken to understand the structures and interactions of the gluten protein complex and how these are established. Nevertheless, our knowledge is still far from complete. We therefore review the current state of our knowledge and identify gaps and priorities for future research. The evidence for the forces that determine the interactions of the individual proteins in the gluten complex is re-evaluated, which allows us to define the relative contributions of covalent disulphide bonds and non-covalent forces (hydrogen bonds, hydrophobic and electrostatic interactions) and to relate these interactions to the amino acid sequences, structures and properties of the individual protein subunits. We also discuss the evidence for the pathway of gluten protein synthesis, deposition and assembly in the developing grain and how the assembly may be modified during the maturation of the grain. [Display omitted] • We review our current knowledge of gluten protein structure and assembly. • We discuss the forces that stabilise protein:protein interactions in gluten. • Hydrophobic and electrostatic forces stabilise gliadin interactions. • Hydrogen bonds stabilise loops and trains formed between HW-GS in polymers. • Outstanding questions and priorities for future research are identified. [ABSTRACT FROM AUTHOR]

We conducted an investigation into the foam and interface properties of wheat aqueous phase protein (WAP) along with its ethanol-soluble fraction (ES) and non-ethanol-soluble fraction (NES). The results reveal that the ES component exhibits exceptional foamability at both pH 5 and 7, whereas the NES component demonstrates relatively lower foamability but excels in foam stability at pH 5 and 7. The ES component shows a higher initial surface pressure, indicating stronger surface activity and, consequently, superior foamability. In contrast, the NES component exhibits a faster adsorption rate. The surface dilatational modulus of all three proteins increases over time and with varying frequencies, forming an interface layer primarily characterized by elastic behavior. Notably, the NES component displays heightened sensitivity to oscillations, suggesting its enhanced capacity to form a stable adsorption layer at the interface, thereby contributing to foam stability. Within WAP, the combined interactions of the ES and NES components dictate its foam properties, with the ES component primarily influencing foamability and the NES component playing a more significant role in foam stability. This study offers valuable insights into the intricate behavior of wheat proteins at gas-liquid interfaces, thereby enhancing our comprehension of the formation and stability mechanisms of dough aqueous phase foams. [Display omitted] • Wheat aqueous phase proteins affects foam and interfacial properties. • Wheat aqueous proteins split into ethanol-soluble and non-ethanol-soluble parts. • Ethanol-soluble part of wheat aqueous phase proteins contribute to foam capacity. • Non-ethanol-soluble part of wheat aqueous proteins contribute to foam stability. [ABSTRACT FROM AUTHOR]

In this study, the effects and mechanisms of different ratios of glutenin/gliadin (Glu/Gli) and calcium ions (Ca2+) on the gel properties of wheat gluten under heat induction were investigated. It was revealed that a high ratio of Glu (6:4∼10:0) improved the elasticity of wheat gluten gel and reinforced the gluten network skeleton, but the gel strength was reduced. A high ratio of Gli (0:10∼5:5) increased gel strength and water-holding capacity (WHC) of the wheat gluten gel, enhancing the gel properties and network structure. The gluten strength, WHC and gel strength responses revealed that a Glu/Gli ratio of 4:6 resulted in the best gel properties of wheat gluten and the strongest water binding ability. Incorporation of 0.004 g/mL Ca2+ significantly promoted the cross-linking between Glu and Glu-Gli, enhanced the binding ability of Gli with water, and strengthened the gel network structure and reaching its peak effect. Intermolecular forces and secondary structure analysis revealed that Ca2+ increased the disulfide bonds in Glu, hydrogen bonds in Gli, and β-sheet content. This indicated that an appropriate amount of Ca2+ formed a Ca2+-gluten protein barrier network through electrostatic shielding, which improved the continuity and compactness of the wheat gluten gel network. Excessive Ca2+ retarded wheat protein cross-linking and hydration capacity, leading to decrease in gel properties. Therefore, by adjusting the Glu/Gli ratio and adding an appropriate amount of Ca2+, the structure and gel properties of wheat gluten can be better controlled, thereby improving the quality of wheat-based products. [ABSTRACT FROM AUTHOR]

Patients with psoriasis have been shown to have a higher prevalence of other autoimmune diseases including celiac disease, a condition marked by sensitivity to dietary gluten. A number of studies suggest that psoriasis and celiac disease share common genetic and inflammatory pathways. Here we review the epidemiologic association between psoriasis and celiac disease and perform a meta-analysis to determine whether patients with psoriasis more frequently harbor serologic markers of celiac disease. We also examine whether a gluten-free diet can improve psoriatic skin disease.

The paper describes the stages of studying the biochemical heterogeneity of gluten proteins of wheat grain as an important factor in the baking quality of flour. It has been shown that the biochemical heterogeneity of gluten proteins is caused by genetic factors. Modern electrophoretic methods on gel carriers make it possible to study the component protein composition of varieties, biotypes, lines, split hybrids and to identify the Mendelian units of the spectrum (genes, alleles). The application of the idea of the genetic nomenclature of the hereditary unit of gliadins (a block of components) is over 40 years old, and it was proposed by domestic scientists (Kopus, Poperelya, Sozinov). This made it possible to compile catalogs of blocks of components (alleles), to study their correlation with quality, frost resistance and other traits, to develop a scale for combining gliadin blocks in the spectrum of varieties for the breeding assessment of samples from agro-nurseries. It has been established that electrophoregrams of prolamins serve as a reliable criterion to identify seed genotypes of commercial varieties by laboratory methods.

Abstract Background In wheat-dependent exercise-induced anaphylaxis (WDEIA), cofactors such as exercise, acetylsalicylic acid (ASA), alcohol or unfavorable climatic conditions are required to elicit a reaction to wheat products. The mechanism of action of these cofactors is unknown, but an increase of gliadin absorption has been speculated. Our objectives were to study gliadin absorption with and without cofactors and to correlate plasma gliadin levels with factors influencing protein absorption in healthy volunteers. Methods Twelve healthy probands (six males, six females; aged 20–56 years) ingested 32 g of gluten without any cofactor or in combination with cofactors aerobic and anaerobic exercise, ASA, alcohol and pantoprazole. Gliadin serum levels were measured up to 120 min afterwards and the intestinal barrier function protein zonulin in stool was collected before and after the procedure; both were measured by ELISA. Stool microbiota profile was obtained by 16S gene sequencing. Results Within 15 min after gluten intake, gliadin concentrations in blood serum increased from baseline in all subjects reaching highly variable peak levels after 15–90 min. Addition of cofactors did not lead to substantially higher gliadin levels, although variability of levels was higher with differences between individuals (p

Abstract Familial loss-of-function mutations of the gene coding for the cystic fibrosis transmembrane conductance regulator (CFTR) channel protein cause cystic fibrosis (CF), the most frequent inherited life-threatening disease in the Caucasian population. A recent study indicates that the gluten/gliadin-derived peptide (P31–43) can cause CFTR inhibition in intestinal epithelial cells, thus causing a local stress response that contributes to the immunopathology of celiac disease (CD). Accordingly, an increased prevalence of CD has been observed in several cohorts of CF patients. CD is characterized by a permanent intolerance to gluten/gliadin proteins occurring in a proportion of susceptible individuals who bear the human leukocyte antigen (HLA) DQ2/DQ8. In CD, perturbations of the intestinal environment, together with the activation of the innate immune system by P31–43, are essential for rendering other immunodominant gliadin peptide fully antigenic, thus triggering an adaptive immune response with an autoimmune component. P31–43-induced CFTR inhibition elicits the danger signals that ignite the epithelial stress response and perturb epithelial proteostasis. Importantly, potentiators of CFTR channel gating, such as the FDA-approved drug Ivacaftor, prevent P31–43 driven CFTR inhibition and suppress the gliadin-induced stress response in cells from celiac patients, as well as the immunopathology developing in gliadin-sensitive mice. Thus, CFTR potentiators may represent a novel therapeutic option for celiac patients.

The construction of the 28-chromosome karyotype of Dasypyrum breviaristatum was undertaken using multicolor non-denaturing fluorescent in situ hybridization (ND-FISH) and Oligo-FISH painting protocols. A novel wheat-D. breviaristatum line D2138 contained 44 chromosomes including a pair of D. breviaristatum 6VbS.2VbL translocation chromosomes. Individual F2 and F3 progenies of a cross between D2138 with wheat lines CM62, MY11 and JM22, respectively, were characterized using ND-FISH and molecular markers. A relatively high chromosome alteration rate within wheat and D. breviaristatum 6VbS and 2VbL was observed in the three progeny populations, suggesting that chromosome 6VbS.2VbL has a gametocidal-like gene. The different types of translocation and deletion lines allowed localization of D. breviaristatum-specific gliadin coding genes on sub-telomeric regions of 6VbS by PCR and acid polyacrylamide gel electrophoresis analysis. The positive effect of the D. breviaristatum 6VbS on agronomic and quality characters was also demonstrated. The new wheat-D. breviaristatum 6VbS and 2VbL translocation lines will be useful as novel germplasm for breeding purposes.

Wheat cultivars grown in North -India were evaluated for their protein characteristics using a modified Osborne fractionation and SDS-PAGE. Gliadin and glutenin subunits and their proportion were also analyzed. The protein content of wheat cultivars varied from 9.32 to 12.60%. Glutenin was found to be the largest fraction comprising of 28.92–49.72% of total protein. SDS- PAGE of albumin resolved into 9–17 bands with a molecular weight range of 6.5–75.1 kDa. Globulin showed polypeptides in the molecular weight range of 3.5–109.7 kDa with the number of bands varying from 15 to 22. Gliadin resolved into polypeptides ranging from 12.5 to 88.4 kDa having some non-gliadin components. Gliadin subunits (α-, β-, and γ-) were the most abundant and varied from 72.16 to 84.46% among different wheat cultivars. A low concentration of ω-gliadins was found in all wheat varieties. The glutenin polypeptides ranged from 11.1 to 128.7 kDa among wheat cultivars. HMW-GS varied significantly (p ≤ 0.05) from 9.82 to 32.95% of the total extractable proteins. LMW-GS ranged from 40.47 to 84.34% among different cultivars. D, B, and C type LMW-GS showed a significant difference (p ≤ 0.05) among wheat cultivars. Correlation established showed a significant relationship between different parameters which can result in affecting the overall quality of the final products.

Gluten sensitivity contributes to various degrees of neurological manifestations and neurodegenerative immunological changes. We investigated the experimental features of anti-gliadin immune responses in the central nervous system (CNS) of mice. Female C57BL6 mice were divided into three groups. Mice immunized with complete Freund's adjuvant (CFA) or gliadin emulsified in CFA, and the control group received phosphate-buffered saline (PBS). Immunohistochemistry, hematoxylin-eosin, and Luxol fast blue staining were performed on the sections. The serum levels of interleukin (IL)-17 and interferon-gamma (IFN-γ) were measured using enzyme-linked immunosorbent assay (ELISA). Reverse transcriptase-polymerase chain reaction (RT-PCR) was used to assess the mRNA levels of chemokine (C-X-C motif) ligand-2 (CXCL-2), C-C motif chemokine ligand-2 (CCL-2), and CXCL-10. In gliadin+CFA immunized mice, the microscopic lesions included perivascular edema, focal-microgliosis, and acute neuronal necrosis in the cortex, subcortical, Purkinje cell layer, and ventral horn of the spinal cord. While extravasation of anti-IgG antibodies and selective targeting of Purkinje cells were observed in gliadin+CFA immunized mice. A significant increase in serum IL-17 and IFN-g levels (p

Celiac disease is an autoimmune disease with genetically determined HLA class II binding DQ2 or DQ8 characterized by intestinal T cell responses to wheat gluten proteins in the diet. The unique a2-gliadin peptide fragment, gliadin-33mer, is considered to be the most important immunogenic sequence in gluten, this peptide is completely resistant to gastrointestinal peptidases and is completely specific for prolamins. Gliadin 33-mer is a stimulator of CD4-T cells after deamidation by tissue transglutaminase. The only proven treatment for celiac disease is a lifelong gluten-free diet, and several new therapeutic approaches are currently being developed. The enzymatic cleavage of gluten by glutenases with a focus on the cytotoxic gliadin 33-mer has been verified in a number of clinical studies. Detection of gluten immunogenic peptides, gliadin 33-mer, in faeces and urine is becoming a new non-invasive biomarker and offers a new simple and objective way to assess gluten intake and verify compliance with a gluten-free diet in patients with celiac disease. In the diagnosis of celiac disease allows you to reliably verify non-responsive celiac disease. [ABSTRACT FROM AUTHOR]

The aim of the study was to asses the genetic variation in 22 accessions of Triticum spelta L. on the basis of quality characteristics and A-PAGE markers. Eleven quality characteristics of grain and whole spelt wheat flour were included in the study. The results of analysis of variance showed high significant differences between spelt wheat accessions. Phenotypic coefficient of variation (PCV) was greater than genotypic coefficient of variation (GCV) for all the traits. High PCV and GCV were observed for sedimentation and fermentation values. High heritability coupled with high genetic advance as percentage of mean was recorded for vitreousness, sedimentation value and fermentation value that indicate selection of such traits may be effective. The cluster analys base on studied characteristics using the Between-groups linkage method group the genotypes into four clusters. Genotypes in the fourth cluster BGR 19018 and BGR 28710 were in the highest rate with respect to thousand kernel weight, vitreousness, crude protein content, wet gluten content, dry gluten content, sedimentation value and fermentation value. In total, 51 polymorphic and 2 monomorphic bands and 20 gliadin patterns were identified by A-PAGE. Fourteen different mobility bands and 13 gliadin patterns were identified in the ω-gliadin zone, 17 bands and 18 patterns were noted in the γ-gliadins, 14 patterns and 10 mobility bands were found for β-gliadins and 12 bands with 16 different α -gliadin patterns were determined. The genetic diversity index (H) was the highest for γ-gliadins (0.908), followed by α -gliadins (0.844), respectively and the lowest value was detected in ω-gliadin patterns (0.804). The genetic similarities (GS) among 22 spelt genotypes estimated by Jaccard’s coefficient ranged from 0.103 to 1. The lowest GS was found between genotypes: BGR 26757 and B2000280, respectively, which indicates that the genetic diversity within these pairs of accessions was very high. Three pairs of genotypes had GS equal to 1 (BGR 10978 and BGR 23639; B2000277 and B2000279; BGR 28710 and BGR 10975), which indicated that they are genetically identical and do not differ in their gliadin spectra. Cluster analysis base on gliadin bands data classified genotypes into 11 main groups. [ABSTRACT FROM AUTHOR]

Backgrounds and objectives: The structure of molded frozen dough cannot be reconstructed before baking; therefore, molding directly affects bread quality. The effect of the addition of acid‐soluble wheat protein (ASP), which consists mainly of gliadin, to molded frozen dough on molding conditions was examined. Findings: Molded (unfermented) frozen dough samples were prepared from the same dough batch at different floor times (assumed potential time differences during dividing). Scanning electron microscopy revealed the presence of cracks in the microstructure of the molded dough. The cracks were caused by gluten damage owing to changes in rheological properties and appeared when the floor time was extended from 5 to 20 min. The addition of ASP maintained the uniformity of the gluten sheet regardless of floor time. Conclusions: The added ASP increased shape uniformity of bread rolls prepared from molded frozen dough and also crumb grain structure and crust appearance uniformity. Significance and novelty: The addition of ASP to molded frozen dough improved bread quality and prevented manufacturing problems that can occur during mechanized bread‐making. Therefore, we anticipate that ASP could also be added to pre‐fermented and par‐baked frozen doughs. [ABSTRACT FROM AUTHOR]

BACKGROUND: Polyphenols may interact with protein via covalent bonds and non‐covalent interactions, improving the structures and functional properties of the protein. The cross‐linking between the polyphenol and protein is susceptible to salt (sodium chloride, NaCl) concentrations. Our study investigated the combined effects of quercetin (Q) and NaCl concentrations on wheat gliadin (G) structure and physicochemical properties. RESULTS: Q and NaCl addition resulted in a more compact protein microstructure. The improved foaming and emulsifying properties indicated that the modified G might be potent as a novel surface‐active agent. Differential scanning calorimetry analysis indicated that Q protected the thermal stability from destruction at 50 and 200 mmol L−1 NaCl concentrations, with narrower protein denaturation peaks. Fourier transform infrared and the Raman spectral analyses showed the secondary structural and microenvironmental changes of G. NaCl addition imparted a rearrangement of hydrogen bonds in the polypeptide chain and the disorder of protein structure, whereas Q enhanced the transition from β‐sheets and random coils to α‐helices and β‐turns, forming a more ordered structure. Moreover, the interaction between G and Q resulted in significant disulfide bridges conformational rearrangements in the protein. CONCLUSION: The results showed the benefits of natural food additives in food processing, which might have potential in improving the structure and physicochemical properties of protein‐based foods. © 2020 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

Gliadins from 25 accessions represented by 350 individual seed samples were analysed by acid-polyacrylamide gel electrophoresis (A-PAGE) with the objective of identifying gliadin band patterns and examine the extent of diversity in Triticum polonicum L. collections from Ethiopia. Seventy polymorphic bands and 68 different patterns were identified. Eighteen different mobility bands and 16 patterns were identified in ω-gliadin region, 22 bands and 20 patterns in γ-gliadin region, 12 bands and 22 patterns in β-gliadin region and 18 bands and 10 patterns in α-gliadin region. The average genetic diversity calculated from the data of the four gliadin zones of the analysed samples was 0.15. The γ region have the highest diversity (H = 0.193), followed by ω regions (H = 0.177) and β region (H = 0.168) and the lowest diversity was observed in α region (H = 0.127). Cluster analysis based on genetic distances resulted in grouping of the analysed accessions in to seven main groups. Though the level of diversity was relatively lower than other tetraploid wheat species from Ethiopia, the findings are indicative of the existence of variation in the collections which can be exploited for wheat improvement.

Gluten proteins are responsible for the wheat breadmaking quality. However, gluten is also related to human pathologies for which the only treatment is a gluten-free diet (GFD). GFD has gained popularity among individuals who want to reduce their gluten intake. Tritordeum is a cereal species that originated after crossing durum wheat with wild barley and differs from bread wheat in its gluten composition. In this work, we have characterized the immunogenic epitopes of tritordeum bread and results from a four-phase study with healthy adults for preferences of bread and alterations in the gut microbiota after consuming wheat bread, gluten-free bread, and tritordeum bread are reported. Tritordeum presented fewer peptides related to gluten proteins, CD-epitopes, and IgE binding sites than bread wheat. Participants rated tritordeum bread higher than gluten-free bread. Gut microbiota analysis revealed that the adherence to a strict GFD involves some minor changes, especially altering the species producing short-chain fatty acids. However, the short-term consumption of tritordeum bread does not induce significant changes in the diversity or community composition of the intestinal microbiota in healthy individuals. Therefore, tritordeum bread could be an alternative for healthy individuals without wheat-related pathologies who want to reduce their gluten consumption without harming their gut health.

Celiac disease (CD) is an autoimmune intestinal disorder caused by the ingestion of gluten in people who carry the susceptible gene. In current celiac disease research, wheat gluten is often the main target of attention, neglecting the role played by non-gluten proteins. This study aimed to describe the effects of wheat amylase trypsin inhibitors (ATI, non-gluten proteins) and gliadin in BALB/c mice while exploring the further role of relevant adjuvants (cholera toxin, polyinosinic: polycytidylic acid and dextran sulfate sodium) intervention. An ex vivo splenocyte and intestinal tissue were collected for analysis of the inflammatory profile. The consumption of gliadin and ATI caused intestinal inflammation in mice. Moreover, the histopathology staining of four intestinal sections (duodenum, jejunum, terminal ileum, and middle colon) indicated that adjuvants, especially polyinosinic: polycytidylic acid, enhanced the villi damage and crypt hyperplasia in co-stimulation with ATI and gliadin murine model. Immunohistochemical results showed that tissue transglutaminase and IL-15 expression were significantly increased in the jejunal tissue of mice treated with ATI and gliadin. Similarly, the expression of inflammatory factors (TNF-α, IL-1β, IL-4, IL-13) and Th1/Th2 balance also showed that the inflammation response was significantly increased after co-stimulation with ATI and gliadin. This study provided new evidence for the role of wheat amylase trypsin inhibitors in the pathogenesis of celiac disease.

Gluten sensitivity contributes to various degrees of neurological manifestations and neurodegenerative immunological changes. We investigated the experimental features of antigliadin immune responses in the central nervous system (CNS) of mice. Female C57BL6 mice were divided into three groups. Mice immunized with complete Freund's adjuvant (CFA) or gliadin emulsified in CFA, and the control group received phosphate-buffered saline (PBS). Immunohistochemistry, hematoxylin-eosin, and Luxol fast blue staining were performed on the sections. The serum levels of interleukin (IL)-17 and interferongamma (IFN-γ) were measured using enzyme-linked immunosorbent assay (ELISA). Reverse transcriptase-polymerase chain reaction (RT-PCR) was used to assess the mRNA levels of chemokine (C-X-C motif) ligand-2 (CXCL-2), C-C motif chemokine ligand-2 (CCL-2), and CXCL-10. In gliadin+CFA immunized mice, the microscopic lesions included perivascular edema, focalmicrogliosis, and acute neuronal necrosis in the cortex, subcortical, Purkinje cell layer, and ventral horn of the spinal cord. While extravasation of anti-IgG antibodies and selective targeting of Purkinje cells were observed in gliadin+CFA immunized mice. A significant increase in serum IL-17 and IFN-γ levels (p<0.05), as well as expression of CXCL-2, CCL-2, and CXCL-10 in mice immunized with gliadin+CFA, were monitored versus controls. Our findings indicated that the immune responses directed against gliadin peptides might contribute to blood-brain barrier breakdown, extravasation of serum anti-IgG, gliosis, and acute neuronal necrosis in the cortex and cerebellar Purkinje cells. Anti-IgG antibodies may cause extravasation of blood-born anti-gliadin antibodies and selective targeting of Purkinje cells observed in mice immunized with peptide tryptic (pt) -gliadin in CFA. [ABSTRACT FROM AUTHOR]

Wheat breads share about 50% of human body calories in many developing communities. There are different kinds of breads differ with the different traditions of the society. Gluten and gliadin proteins play a major part of baking quality of wheat bread. Oriental bread is the most sensitive to quality and percent of gluten proteins in grains. Viscosity of dough helps making better oriental bread. Puffing, blisters on breads surface, and palatability of bread could be improved by mixing bread wheat flour with xylanase enzyme, vital wheat gluten, and some other additives. Whole grain wheat breads are more nutritious, for containing high quality of fibers, vitamins, minerals, proteins, antioxidants, and carbohydrates. Mixing an optimum percent of durum wheat flour with poor quality bread wheat enhances the baking quantity so well. The genetics of gluten and gliadin bread wheat is so complex. Polymorphism, multigenes loci, epigenetics and epigenomics play several roles in this complicated trait. Splitted dozes of nitrogen enhances quality of wheat bread, although, it could not increase grain yield when added at anthesis or pre-anthesis. More research is still needed on wheat bread quality on farm, and into the laboratory. [ABSTRACT FROM AUTHOR]

The choice of a (bio)material plays a crucial role in the development of a drug delivery system because it confers specific biopharmaceutical properties to the formulation and modulates the pharmacokinetic and pharmacodynamic features of the entrapped compound(s). In this context, the exploitation of natural raw materials is increasing due to their versatility and safety. Some of them can be recycled from agricultural biomasses and are a way to valorize waste for pharmaceutical and biomedical purposes. In this regard, plant proteins emerge as convenient raw materials because of their wide availability, low-cost and possibility of being chemically modified and degraded into safe by-products. Among them the gliadins, alcohol-soluble prolamins obtained from wheat, are versatile polymers to be used for the development of various systems and for different applications. The aim of this review is to provide a comprehensive overview concerning the use of gliadins as biomaterials useful for furnishing nanoparticles, nanofibers and films with the capacity to retain various active compounds. In addition, the most important pharmaceutical, biomedical, alimentary and cosmetic applications of these formulations will be discussed. Unlabelled Image • Gliadins are a blend of proteins extracted from wheat. • Gliadin-based nanoparticles have peculiar bioadhesive properties. • Chemical modification of gliadin can enhance its solubility. • Gliadin-based films can be employed as biodegradable food-grade packaging materials. • Gliadin nanofibers have potential application for tissue engineering. [ABSTRACT FROM AUTHOR]

Copyright of Acta Agriculturae Slovenica is the property of Biotechnical Faculty of the University of Ljubljana and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Although wheat (Triticum aestivum L.) grain protein content is increased by shade stress, the relationship between the baking quality of wheat flour and protein composition and structure remains unclear. Here, we investigated the effects of shade stress on wheat flour protein composition and structure. The contents of the flour protein, α/β-gliadins and disulfide and hydrogen bonds were significantly increased by shade stress. Glutenins, UPP%, and β-sheet contents also increased, whereas that of α-helices decreased. Spearman correlations revealed that the flour protein content, Glu:Gli ratio, and disulfide, hydrogen, and ionic bonds can predict the specific volume and number of crumb cells in bread, whereas α/β-gliadins content can predict the crumb cell wall thickness and diameter of bread. Under shade stress, variations in protein composition and structure help increase the specific volume and crumb cells number and decrease crumb cell wall thickness and diameter of bread, ultimately leading to improved baking quality., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

This study investigated the effects of ethanol (0 %∼6%) on the dough mechanical properties and quality characteristics of fresh noodles and elucidated the relationship between the above changes and physicochemical, structural, and molecular properties of gluten. Ethanol reduced the water absorption (from 59.00 % to 52.33 %), stability time (from 8.17 min to 3.33 min) and viscoelasticity of dough, and increased the development time, weakening degree and compliance. Ethanol also decreased the fracture stress of dough sheet, and increased fracture elongation and adhesiveness (from 46.15 g·s to 75.88 g·s). Ethanol decreased the noodles' hardness (from 5347.41 g to 4442.34 g), break force, tensile distance, and water absorption, while cooking loss was increased. SEM and CLSM showed that ethanol destroyed the compactness of internal structure and inhibited the formation of gluten network in noodles. According to the results of SE-HPLC and RP-HPLC, ethanol dissolved part of the gliadin and inhibited the polymerization of protein., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

Plant-based adhesives, such as those made from wheat, have been prominently used for books and paper-based objects and are also used as conservation adhesives. Starch paste originates from starch granules, whereas flour paste encompasses the entire wheat endosperm proteome, offering strong adhesive properties due to gluten proteins. From a conservation perspective, understanding the precise nature of the adhesive is vital as the longevity, resilience, and reaction to environmental changes can differ substantially between starch- and flour-based pastes. We devised a proteomics method to discern the protein content of these pastes. Protocols involved extracting soluble proteins using 0.5 M NaCl and 30 mM Tris-HCl solutions and then targeting insoluble proteins, such as gliadins and glutenins, with a buffer containing 7 M urea, 2 M thiourea, 4% CHAPS, 40 mM Tris, and 75 mM DTT. Flour paste's proteome is diverse (1942 proteins across 759 groups), contrasting with starch paste's predominant starch-associated protein makeup (218 proteins in 58 groups). Transformation into pastes reduces proteomes' complexity. Testing on historical bookbindings confirmed the use of flour-based glue, which is rich in gluten and serpins. High levels of deamidation were detected, particularly for glutamine residues, which can impact the solubility and stability of the glue over time. The mass spectrometry proteomics data have been deposited to the ProteomeXchange, Consortium (http://proteomecentral.proteomexchange.org) via the MassIVE partner repository with the data set identifier MSV000093372 (ftp://MSV000093372@massive.ucsd.edu).

The intestinal immune system plays a crucial role in obesity and insulin resistance. An altered intestinal immunity is associated with changes to the gut microbiota, barrier function, and tolerance to luminal antigens. Lipid metabolism and its unbalance can also contribute to acute and chronic inflammation in different conditions. In celiac disease (CD), the serum phospholipid profile in infants who developed CD is dramatically different when compared to that of infants at risk of CD not developing the disease. In a mouse model of gluten sensitivity, oral wheat gliadin challenge in connection with inhibition of the metabolism of arachidonic acid, an omega-6 polyunsaturated fatty acid, specifically induces the enteropathy. Recent evidence suggests that gluten may play a role also for development of life-style related diseases in populations on a high fat diet (HFD). However, the mechanisms behind these effects are not yet understood. Exploratory studies in mice feed HFD show that wheat gliadin consumption affects glucose and lipid metabolic homeostasis, alters the gut microbiota, and the immune cell profile in liver., (© 2024 Wiley‐VCH GmbH.)

Unsaturated fatty acids present in fish oil offer various physiological benefits to the human body. However, their susceptibility to oxidation severely limits their potential applications. The purpose of this study was to develop Pickering emulsions stabilized from a composite of resveratrol-loaded gliadin nanoparticles and oxidized chitin nanocrystals (GR/OC) to protect fish oil from oxidation. The effects of the GR/OC composite on the characterizations of fish oil Pickering emulsions were investigated, including the microstructure, physicochemical properties (stability and rheological behavior), and digestion properties in vitro. The results revealed that an increased concentration of the GR/OC composite significantly reduced the droplet size and improved the ambient stability of the emulsions (in terms of pH, ionic strength, temperature, and storage time). Confocal laser scanning microscopy images depicted that the GR/OC nanoparticles were uniformly dispersed at the interface between water and fish oil (W-O interface). This distribution formed a protective envelope around the droplets. Remarkably, the addition of 2% GR/OC nanoparticles stabilized the Pickering emulsions and showed the most positive effect on the antioxidant capacity compared to that of the control group. These stabilized emulsions maintained lower peroxide values and acid values, which were 1.5 times less than those of the blank control during the 14 day accelerated oxidation experiment. Furthermore, the Pickering emulsions stabilized by GR/OC nanoparticles exhibited the ability to protect fish oil from contamination by gastric juices and facilitate the intestinal absorption of omega-3 polyunsaturated fatty acids. The findings suggest that these GR/OC-stabilized Pickering emulsions offer a promising alternative for delivering fish oils in various industries, including the food industry.

Objective: Food products with <20 mg/kg gluten can be labeled 'gluten-free' according to international regulations. Several antibodies-based ELISAs have been develop to track gluten traces in food products. Among them, R5 and G12 antibody-based ELISAs are the frequently used methods. However, these antibodies have certain limitations. We evaluated the accuracy of G12/A1 antibody-based 'Glutentox ELISA Rapid G12' and compared the results with the current reference method i.e., R5 antibody-based 'Ridascreen R5 ELISA'., Methods: In the first step, the performance of Glutentox ELISA Rapid G12 kit was inspected by determination of the threshold value i.e., > or <20 mg/kg gluten in different food products. In the second step, quantification accuracy was assessed by quantification of gluten in gluten-free food products spiked with gliadin reference material., Results: In total 47 food products (naturally and labeled gluten-free, and food with traces of gluten) were included. Of them, 29 products were quantified with <20 mg/kg, and 18 with a low level of gluten by both the kits. Six out of 29 gluten-free products were used for the recovery test at different spike levels. Gluten concentration and mean recovery rates of individual kits showed consistency., Conclusion: GlutenTox Rapid G12 ELISA could be an appropriate choice for detecting gluten in food products but needs more in-house validation and collaborative tests., (Copyright © 2024 Wolters Kluwer Health, Inc. All rights reserved.)

Celiac disease is a gluten-induced hypersensitivity reaction that requires a lifelong gluten-free diet. Gluten-free foods must not contain more than 20 mg/kg gluten as laid down by Codex Alimentarius. Measuring the presence of gluten with routine immunoanalytical methods in food is a serious challenge as many factors affect accurate determination. Comparability of the results obtained with different methods and method validation are hindered by the lack of a widely accepted reference material (RM). The core questions of RM development from wheat are the number of cultivars to be included and the format of gluten (i.e., flour, gluten, or gliadin isolates) to be applied. Therefore, the aim of our work was to produce an appropriate gluten RM from wheat. For this, five previously selected wheat cultivars and their blend were used to produce flours, gluten and gliadin isolates under laboratory conditions. Protein content, protein composition and responses to different ELISA methods were compared and widely evaluated in our study. The protein contents of the flours were 12.1–18.7%, those of the gluten isolates 93.8–97.4% and those of the gliadin isolates 72.7–101.9%. The gluten and gliadin isolates had similar protein profiles as the source flours. By comparing the different wheat cultivars and their protein isolates, we found that the isolation had a smaller effect on protein composition than genetic variability. The choice of a blend would be more suitable for the production of a RM in case of flours and also isolates. The immunoanalytical results showed that the isolation had an effect on the analytical results, but its extent depended on the ELISA method. The use of flour would be more applicable in this regard, but handling of the material and long-term stability should also be considered in the final decision of gluten RM production.

Ingestion of gluten proteins (gliadins and glutenins) from wheat, barley and rye can cause coeliac disease (CD) in genetically predisposed individuals. The only remedy is a strict and lifelong gluten-free diet. There is a growing desire for coeliac-safe, whole-grain wheat-based products, as consumption of whole-grain foods reduces the risk of chronic diseases. However, due to the large number of gluten genes and the complexity of the wheat genome, wheat that is coeliac-safe but retains baking quality cannot be produced by conventional breeding alone. CD is triggered by immunogenic epitopes, notably those present in α-, γ-, and ω-gliadins. RNA interference (RNAi) silencing has been used to down-regulate gliadin families. Recently, targeted gene editing using CRISPR/Cas9 has been applied to gliadins. These methods produce offspring with silenced, deleted, and/or edited gliadins, that overall may reduce the exposure of patients to CD epitopes. Here we review methods to efficiently screen and select the lines from gliadin gene editing programs for CD epitopes at the DNA and protein level, for baking quality, and ultimately in clinical trials. The application of gene editing for the production of coeliac-safe wheat is further considered within the context of food production and in view of current national and international regulatory frameworks.

Wheat gluten proteins are the known cause of celiac disease. The repetitive tracts of proline and glutamine residues in these proteins make them exceptionally resilient to digestion in the gastrointestinal tract. These indigested peptides trigger immune reactions in susceptible individuals, which could be either an allergic reaction or celiac disease. Gluten exclusion diet is the only approved remedy for such disorders. Recently, a combination of a glutamine specific endoprotease from barley (EP-B2), and a prolyl endopeptidase from Flavobacterium meningosepticum (Fm-PEP), when expressed in the wheat endosperm, were shown to reasonably detoxify immunogenic gluten peptides under simulated gastrointestinal conditions. However useful, these “glutenases” are limited in application due to their denaturation at high temperatures, which most of the food processes require. Variants of these enzymes from thermophilic organisms exist, but cannot be applied directly due to their optimum activity at temperatures higher than 37°C. Though, these enzymes can serve as a reference to guide the evolution of peptidases of mesophilic origin toward thermostability. Therefore, a sequence guided site-saturation mutagenesis approach was used here to introduce mutations in the genes encoding Fm-PEP and EP-B2. A thermostable variant of Fm-PEP capable of surviving temperatures up to 90°C and EP-B2 variant with a thermostability of up 60°C were identified using this approach. However, the level of thermostability achieved is not sufficient; the present study has provided evidence that the thermostability of glutenases can be improved. And this pilot study has paved the way for more detailed structural studies in the future to obtain variants of Fm-PEP and EP-B2 that can survive temperatures ~100°C to allow their packing in grains and use of such grains in the food industry.