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The effect of puroindolines (PINs) on structural characteristics of wheat proteins was investigated in Triticum turgidum ssp. durum (cv. Svevo) and Triticum aestivum (cv. Alpowa) and in their respective derivatives in which PIN genes were expressed (Soft Svevo) or the distal end of the short arm of chromosome 5D was deleted and PINs were not expressed (Hard Alpowa). The presence of PINs decreased the amount of cold-SDS extractable proteins and the accessibility of protein thiols to specific reagents, but resulted in facilitated solvation of gluten proteins, as detected by tryptophan fluorescence measurements carried out on minimally mixed flour/water mixtures. We propose that PINs and gluten proteins are interacting in the grain or flour prior to mixing. Hydrophobic interactions between PINs and some of the gluten proteins modify the pattern of interactions among gluten proteins, thus providing an additional mechanistic rationale for the effects of PINs on kernel hardness.

The Gluten FriendlyTM Technology is an innovative method that induces structural changes in gluten proteins. In this paper a synbiotic fermented milk, containing Lactobacillus acidophilus La-5 and Gluten Friendly Flour (GFF), was proposed. A mixture design was used to combine flour, temperature and probiotic to study the effects of these variables on the acidification. The experiments were done on both GFF and control flour (CF). Thus, the following conditions were chosen to produce the fermented milk: L. acidophilus at 6.5 log cfu/ml; flour at 2.5 g/l; temperature at 37°C. Then, the fermented milk was produced and stored at 4°C for 90 days. The most important result was the positive effect of GFF on the viability of the probiotic, with a prolongation of the shoulder length to 20 days (12–13 days in the control). Moreover, GFF did not act on the sensory scores and on the physico-chemical parameters.

Dietary fibres are regarded as the source of polysaccharides and antioxidants such as polyphenols. However, addition of dietary fibre to bread causes significant reduction in its quality. The bread quality is connected with the structure of gluten proteins. For this reason, Fourier transform Raman spectroscopy was applied to determine changes in structure of gluten proteins modified by seven dietary fibres. The fibres were added to model flour reconstituted with wheat gluten and wheat starch. The model flour was used to provide gluten proteins of definite structure. The obtained results showed that six out of seven fibres caused similar changes in β-turn structures. The appearance of the band at 1642 cm−1 and the shift toward lower wavenumbers of the band at 1670 cm−1 in the difference spectra indicated hydrogen bonding of carbonyl groups in β-turns leading to protein folding/aggregation. Addition of fibre preparations caused also changes in conformation of disulfide bridges (S–S), corresponding to transformation to trans-gauche-gauche and trans-gauche-trans conformations at the expense of the stable gauche-gauche-gauche conformation. The S–S bonds in less stable conformations were formed inside the protein complex as well as between protein complexes in the form of β-structures. Generally, the observed changes in gluten proteins after addition of dietary fibres were results of interactions between fibre polysaccharides and gluten proteins rather than between polyphenols and gluten proteins. Copyright © 2015 John Wiley & Sons, Ltd.

The network-forming attributes of gluten have been investigated for decades, but no study has comprehensively addressed the differences in gluten network evolution between strong and weak wheat types (hard and soft wheat). This study monitored changes in SDS protein extractability, SDS-accessible thiols, protein surface hydrophobicity, molecular weight distribution, and secondary structural features of proteins during mixing to bring out the molecular determinants of protein network formation in hard and soft wheat dough. Soft wheat flour and dough exhibited greater protein extractability and more accessible thiols than hard wheat flour and dough. The addition of the thiol-blocking agent N-ethylmaleimide (NEM) resulted in similar results for protein extractability and accessible thiols in hard and soft wheat samples. Soft wheat dough had greater protein surface hydrophobicity than hard wheat and exhibited a larger decrease in surface hydrophobicity in the presence of NEM. Formation of high-molecu...

Wheat gluten contains peptide sequences, which activate specific T cells causing a chronic inflammation of the small intestine in celiac disease patients. It is well established that next to wheat gluten, the gluten-like proteins in barley and rye are similarly harmful to celiac disease patients whereas oat is generally considered safe. This study focuses on the development of an ELISA method for the detection of native and processed gluten proteins. The developed test utilizes a monoclonal antibody specific for the DQ2.5-glia-α3 T cell epitope present in the α-gliadins, which are part of wheat gluten that triggers celiac disease. The developed competitive ELISA uses a synthetic DQ2.5-glia-α3 peptide standard for calibration. The conversion from the measured DQ2.5-glia-α3 peptide concentration to gliadin content is achieved by using the experimentally determined multiplication factor of 250. The gluten content can be then calculated by multiplying the gliadin concentration by a factor of 2. A simple sample preparation method with 60% ethanol is used to extract the disease-causing proteins from cereals and processed foods. The assay was found to be specific for the detection of gluten from wheat, barley and rye with no cross-reaction with 8 tested oat varieties. The LOD and LOQ for gliadin were calculated based on the results obtained for 60 blank oats samples and they were 2.9 and 3.6 ppm, respectively. The assay could detect as little as 0.01% wheat gluten and gluten-like proteins from rye and barley in oats. The ELISA was also found to be applicable to the analysis of a range of processed food such as sauces, beers, soups and bread. In conclusion, the developed assay is a sensitive, specific and cost-effective tool for screening cereals and processed foods for the presence of harmful wheat gluten and gluten-like proteins from barley and rye.

Celiac disease, characterized by autoimmune reactions to dietary gluten, affects up to 3 million in the US and approximately 0.5%–1% globally. A strict, lifelong gluten-free diet is the only treatment. An economic, simple, accurate, rapid and portable gluten testing device would enable gluten-sensitive individuals to safeguard their food safety. We developed a novel solution, Nima™, a gluten sensor that integrates food processing, gluten detection, result interpretation and data transmission in a portable device, detecting gluten proteins at or below the accepted 20 ppm threshold. We developed specific monoclonal antibodies, an optimized lateral flow immunoassay strip, and one-step aqueous extraction. Compared with reference R5, Nima TM antibodies (13F6 and 14G11) had 35- and 6.6-fold higher gliadin affinities, respectively. We demonstrated device performance using a comprehensive list of foods, assessing detection sensitivity, reproducibility, and cross-reactivity. Nima™ presented a 99.0% true positive rate, with a 95% confidence interval of 97.8%–100%.

Among the three major food crops (rice, wheat and maize), wheat is unique in accumulating gluten proteins in its grains. Of these proteins, the high and low molecular weight glutenin subunits (HMW-GSs and LMW-GSs) form glutenin macropolymers that are vital for the diverse end-uses of wheat grains. In this work, we developed a new series of deletion mutants lacking one or two of the three Glu-1 loci (Glu-A1, -B1 and -D1) specifying HMW-GSs. Comparative analysis of single and double deletion mutants reinforced the suggestion that Glu-D1 (encoding the HMW-GSs 1Dx2 and 1Dy12) has the largest effects on the parameters related to gluten and dough functionalities and breadmaking quality. Consistent with this suggestion, the deletion mutants lacking Glu-D1 or its combination with Glu-A1 or Glu-B1 generally exhibited strong decreases in functional glutenin macropolymers (FGMPs) and in the incorporation of HMW-GSs and LMW-GSs into FGMPs. Further examination of two knockout mutants missing 1Dx2 or 1Dy12 showed that 1Dx2 was clearly more effective than 1Dy12 in promoting FGMPs by enabling the incorporation of more HMW-GSs and LMW-GSs into FGMPs. The new insight obtained and the mutants developed by us may aid further research on the control of wheat end-use quality by glutenin proteins.

peer-reviewed, The aim of this study was to compare efficiency of RP-HPLC (Reversed-Phase High-Performance Liquid Chromatography) and LOC (Lab-on-Chip) methods for wheat gluten protein quantification regarding clustering of wheat cultivars according to the genetic similarity (HMW-GS combinations), as well as to explore relations of these two methods to wheat quality parameters. For that purpose, wheat quality parameters (protein content, falling number, wet gluten content, gluten index, Farinograph, Extensograph, and Amylograph), as well as amounts of gliadin and glutenin fractions by RP-HPLC and LOC methods were determined in two different sets of wheat cultivars (Croatian and Serbian). The percentages of gluten proteins and the values of quality parameters were used to characterize the samples by principal component analysis (PCA). Gluten protein quantification performed by method based on the protein fraction separation by molecular weights (LOC) was better for grouping of genetically similar wheat cultivars than quantification of proteins separated by their different solubility in specified solvent gradient (RP-HPLC). LOC method showed higher potential in wheat quality prediction., This work was supported by the Ministry of Education, Science and Technological Development of the Republic of Serbia within the Project of technological development No. TR 31007 and bilateral cooperation between Serbia and Croatia — Genetic polymorphism of gluten proteins and its relationship to bread-making quality of wheat (Triticum aestivum L.). Dr. Nikola Hristov from Institute of Field and Vegetable Crops (Novi Sad, Serbia) is also acknowledged for providing one set of examined cultivars

This study investigated the effects of water-extractable arabinoxylan (WEAX) on gluten by thermal treatment. Fourier transform infrared spectroscopy (FTIR) results showed that heating significantly decreased β-sheets and β-turn structures in gluten proteins between 25 and 55 °C. The addition of WEAX caused a transition from β-turn to β-sheets at >55 °C. The ratio of weakly hydrogen-bonded β-sheets to strongly hydrogen-bonded β-sheets demonstrated an increasing trend with temperature increasing, but WEAX can hinder this process. FT-Raman results revealed that a hydrophilic environment was developed with 5% WEAX at 25 °C, and phenolic hydroxyl on ferulic acid can form new H-bonds with the phenyl groups of the nondissociated Tyr residues. A 5% WEAX content is helpful for gluten to maintain its original gauche–gauche–gauche conformation of disulfide bond upon heating. In addition, WEAX can reduce the elasticity of gluten and form a soft texture at 25, 55, and 75 °C.

A formulation with rice flour as the major component to manufacture white salted noodles was developed. However, rice flour is not suitable for the manufacture of white salted noodles due to the lack of gluten proteins. With the application of transglutaminase (TGase) to catalyze the formation of covalent cross-linking bonds between protein molecules and with the incorporation of vital gluten and wheat flour to increase the protein content and to mimic the color and sensory characteristics, white salted noodles with rice flour, vital gluten and wheat flour at the ratio of 80:10:10 were obtained. Noodles prepared without TGase showed significantly (p

peer-reviewed, The objective of this study was to monitor the changes in the content of free amino groups during postharvest wheat and flour maturation. The content of free amino groups of wheat flour was analysed immediately after wheat harvest, after 50 days of wheat storage and after 14 days of flour storage varying by wet gluten samples incubation temperatures and incubation times (0, 90 or 135 min at 30 °C and after that 180 min at 37 °C). The results were observed in relation to wheat-bug damaged kernels content, gluten index values, proteolytic activity and electrophoretic properties of gliadins and glutenins. The content of free amino groups increased during postharvest wheat and flour maturation periods. Proteolytic activity values were the highest 50 days after the wheat storage. The electrophoretic determination indicated a macromolecular redistribution of the gluten proteins from the moment of the wheat harvest until the moment of flour stabilisation., This paper is a result of the research within the project TR 31007 financed by the Ministry of Education, Science and Technological Development, Republic of Serbia.

Wheat (Triticum aestivum L.) is the most widely used basic staple for mankind. Wheat is also one of the most important cereals in Hungary with a high economic value. The aim of wheat production is twofold; to provide quantity and quality. Milling and baking quality of wheat is mainly determined by the genetic basis, however it can be influenced by management techniques. Storage proteins account for more than half of the total protein in mature cereal grains and have important impacts on their nutritional quality for humans and livestock and on their functional properties in food processing. Gluten proteins - gliadins and glutenins of wheat determine the quality of the grain for breadmaking and their amount and composition can be influenced by agronomic impacts leading to changes in dough properties and that of baking quality. The present review is dealing with the impact of various agronomic and environmental factors on the performance of storage proteins and within them gluten proteins.

Little if any literature is available on the functionality of gluten proteins in yeast leavened developed dough systems containing high sugar and fat levels. We here studied whether and to what extent gluten proteins impact the different phases of the production of such a system (which contains about 35 parts invert syrup and 70 parts margarine per 100 parts flour) and how these proteins affect its quality. In a first approach, we used model systems based on gluten–starch blends as this allowed specifically altering the gluten levels without altering the gluten quality and/or levels of other wheat flour components. In a second approach flour was heat treated upfront to alter its gluten proteins. Despite the large amounts of sugars and fat, the presence of a developed gluten network in these systems allowed dough pieces to retain gas during fermentation. Also, dough pieces with a developed gluten network could expand faster during subsequent baking than dough pieces without a developed gluten network (i.e. ca. 3.6 vs. 1.9 cm/min, respectively). Remarkably, at a given moment during baking (i.e. between 65 and 105 sec of baking), dough pieces started to shrink in all directions. This was related to the (elastic) protein network present in the system. However, the time at which shrinking occurred was influenced by factors other than the gluten network. Besides the level, the quality of the gluten fraction determined gluten development during mixing of dough systems containing high levels of sugars and fat, and thus, the spread behavior during fermentation and baking and the final product's dimensions.

Enzyme-linked immunosorbent assays (ELISAs) for gluten quantitation use specific antibodies that interact with epitopes of gluten proteins that trigger an immune response in celiac disease patients. To date, four ELISA methods for gluten quantitation have been validated by international collaborative studies. The Skerritt ELISA method was validated in 2001. Three proprietary gluten ELISA methods have since been developed and were validated between 2010 and 2013: the R5 sandwich ELISA, R5 competitive ELISA, and G12 sandwich ELISA kits. In collaborative studies, the R5 sandwich ELISA had a limit of detection (LOD) of 3 mg of gluten/kg and a relative reproducibility standard deviation (RSDR) of 17 to 27% for samples containing intact gluten, whereas the G12 sandwich ELISA had an LOD of 4 mg of gluten/kg and an RSDR of 19 to 33% in 8 of 9 samples containing intact gluten. The R5 competitive assay targets hydrolyzed gluten and was less sensitive (LOD of 10 mg/kg) and showed higher variation (RSDR of 25 to 37%)...

The aim of the present research was to modify wheat gluten by binding methionine to gluten proteins to develop bread for celiac disease (CD) patients. The highest protein content, wet gluten content, dry gluten content and sodium dodecyl sulphate-sedimentation value were shown by the wheat variety AARI-11, therefore, it was selected for gluten modification. The bound methionine to gluten proteins was found increasing along the reaction time as the reaction proceeds and at a maximum near to 60 minutes and then it starts decreasing. The lowest immunoreactivity of the modified gluten was obtained near to 60 min of reaction at pH 10. The results for immunoglobulin A (IgA) index showed that the serum of each patient had positive IgA index to gliadins from unmodified gluten, but just sera of two patients had positive IgA index to gliadins from modified gluten and when these proteins were digested, the sera of no patient's serum had positive IgA reactivity. Among physical characteristics of breads 2 hours after ...

Physical and chemical techniques were applied to characterize the type of interaction between hydrocolloids and the gluten network in wheat dough, with and without NaCl. Modified celluloses (microcrystalline cellulose, MCC; carboxymethylcellulose, CMC, hydroxypropylmethylcelluloses, HPMC) and pectins of low (LMP) and high (HMP) degree of methylation were utilized as hydrocolloids to interact with gluten proteins. Modified celluloses were employed at 1.5% (flour basis) and pectins at 2.0% (flour basis). By microscopy (SEM and CLSM), it could be observed that NaCl induced a more marked crosslinking and orientation of gluten network. On the other hand, the addition of hydrocolloids led to more open matrices. Molecular mobility was evaluated by 1H-NMR assays and significant effects of NaCl addition and hydrocolloid type were found on relaxation times (T2). In presence of salt, significantly higher relaxation times were observed when modified celluloses were added. Hydrocolloid addition strongly affected the secondary conformation of proteins as studied by FT-Raman. In absence of NaCl, control and MCC samples exhibited the higher α-helix conformation percentage (indicating a more ordered and compact structure), followed by dough with HMP, HPMCs, LMP and CMC. In general, doughs with modified celluloses and NaCl showed a decrease of α-helix conformation. CMC dough showed the smallest percentage of α-helix conformation, and the highest contributions of more unfolded structures. Doughs with pectins and NaCl showed similar percentages of α-helix to control one but an increase of random coil structure was observed. Electrophoresis assays confirmed that the presence of certain hydrocolloids (CMC) during gluten formation could affect protein interaction promoting subunits lability from the matrix. Fil: Correa, María Jimena. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Universidad Nacional de la Plata. Facultad de Ciencias Exactas. Centro de Investigación y Desarrollo en Criotecnología de Alimentos; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Exactas; Argentina; Argentina Fil: Evelina Ferrer. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Química Inorgánica "Dr. Pedro J. Aymonino". Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Química Inorgánica "Dr. Pedro J. Aymonino"; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Exactas; Argentina Fil: Maria Cristina Añón. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Universidad Nacional de la Plata. Facultad de Ciencias Exactas. Centro de Investigación y Desarrollo en Criotecnología de Alimentos; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Exactas; Argentina; Argentina Fil: Ferrero, Cristina. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Universidad Nacional de la Plata. Facultad de Ciencias Exactas. Centro de Investigación y Desarrollo en Criotecnología de Alimentos; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Exactas; Argentina; Argentina

Celiac disease is a food-induced enteropathy resulting from exposure to gluten in genetically predisposed individuals. The non-celiac gluten sensitivity (NCGS) is a less known syndrome whose prevalence is under-estimated. The last decades have seen changes in the clinical presentation of both diseases. One possible explanation is that changes in the gluten-rich cereals themselves were the principal causes. Celiac-triggering gluten proteins are indeed expressed to higher levels in modern cereals while non-triggering proteins are expressed less. Sophisticated hybridization techniques have been used to produce new strains of modern wheat, the most high-yielding of which have since made their way into human foods in the absence of animal or human safety testing. The dramatic changes in the clinical presentation of celiac disease and NCGS have taken place when new cereal hybrids were introduced into human foods. This is a critical medical and environmental issue which needs to be investigated by appropriate studies.

The interrelations among wheat protein fractions with different solubility and molecular weight properties were studied using multivariate (PCA) analysis and obtained trends were used as the base for investigations related to differentiation of technological quality among wheat cultivars with different combination of protein fractions compositions using univariate statistcs (ANOVA followed by Duncans test) in order to draw out information about interrelations between protein fractions composition in wheat cultivars and their technological quality. Data on protein fractions composition obtained with RP-HPLC and technological quality parameters for 26 wheat cultivars grown in Serbia and Croatia in the region of south Panonian plane were used to form the data base. Analysis based on first four PCA factors which explained 89.04% variability of protein composition in investigated wheat cultivars pointed out at interdependences between: (1) low protein and gluten content and susceptibility to enzymatic processes in dough, (2) high content of albumins and globulins, low gliadins content and gliadins/glutenins ratio, high α- gliadins, low molecular weight glutenins and low α- gliadins share in total protein with low water absorption, high energy and high resistance to extensibility ratio, (3) high albumin and globulin content and high share of omega-gliadins in total protein and low extensograph extensibility, (4) high HMW-GS share in total proteins, high extensograph resistance/extensibility ratio and (5) high gamma- gliadins share in total protein and low extensograph resistance/extensibility ratio. Applied statistical approach confirmed also interdependence between high protein and gluten content and longer dough development time and high extensograph energy.

Gluten proteins composed of gliadins and glutenins are important contributors to the wheat quality properties. 28 winter wheat cultivars differing in bread processing quality were collected at the experimental fields of the Agricultural Institute Osijek, Croatia, in growing season 2006/2007. The HMW-GS composition and gliadins content were determined by SDS-PAGE and RP-HPLC, respectively, with the aim to determine their relationship with wheat quality properties. Based on gliadins and HMW-GS data for 28 wheat cultivars developed are PLS models for prediction of 15 baking quality parameters. Applied is NIPALS algorithm for evaluation of the latent variables and regression coefficient parameters. Obtained 4-th order models have average coefficients of determination R2 =0.80. Determined variable importance in projections (VIP) coefficients revealed that HMW- GS data have the dominant influence on the baking quality parameters. For extensographic and farinographic properties the Glu-D1 locus has the main VIP coefficient while Glu-B1 locus is the most important for the indirect quality parameters. The derived PLS models and VIP coefficients could be used in molecular based wheat selection and breeding program.

Gluten that is present in food as a result of cross-contact or misbranding can cause severe health concerns to wheat-allergic and celiac patients. Immunoassays, such as enzyme-linked immunosorbent assay (ELISA) and lateral flow device (LFD), are commonly used to detect gluten traces in foods. However, the performance of immunoassays can be affected by non-assay-related factors, such as food matrix and processing conditions. Gluten (0-500 ppm) and wheat flour (20-1000 ppm) incurred cornbread was prepared at different incurred levels and baking conditions (204.4 °C for 20, 27, and 34 min) to study the accuracy and precision of gluten measurement by seven immunoassay kits (three LFD and four ELISA kits). The stability and immunoreactivity of gluten proteins, as measured by western blot using three different antibodies, were not adversely affected by the baking conditions. However, the gluten recovery varied depending upon the ELISA kit and the gluten source used to make the incurred cornbread, affecting the accuracy of gluten quantification (BioKits, 9-77%; Morinaga, 91-137%; R-Biopharm, 61-108%; and Romer Labs, 113-190%). Gluten recovery was reduced with increased baking time for most ELISA kits analyzed. Both the sampling and analytical variance increased with an increase in the gluten incurred level. The predicted analytical coefficient of variation associated with all ELISA kits was below 12% for all incurred levels, indicative of good analytical precision.

The composition of protein fractions, particularly gluten protein, determines the nutritional values and baking properties of wheat grain. The baking characteristics of grain are strongly related to the quantity of monomeric gliadins and polymeric glutenins. Their accumulation and proportions impact the viscosity, porosity, and degree of rising in baking. These properties determine the applications of wheat in the baking industry. The changes in protein composition are mainly influenced by the genotype, the environment, and the interactions between the genotype and the environment and fertilization. The presented results of the studies refer to the impact of fertilization using waste products (meat bone meals, MBMs) originating from the recycling industry, in comparison to organic and mineral fertilizers, on the technological quality of spring and winter wheat based on the proportion of gluten proteins. The content of gluten proteins, particularly high molecular weight (HMW) and low molecular weight glute...

To probe the thermal and structural properties of gluten proteins using ultrasound.A new ultrasonic approach for characterizing the quality of wheat gluten proteins is described. Low frequency (50 kHz) longitudinal ultrasonic velocity, v L, measurements were performed on gluten samples extracted from three wheat flours differing in protein content and in wheat endosperm hardness.At room temperature, v L for gluten extracted from soft flowers (Fielder) was found to be (870 ± 92) m/s, while for gluten extracted from extra strong flours (Glenlea) it was found to be (1,940 ± 90) m/s. In the second set of experiments, which aimed at probing thermal properties of gluten proteins, the variation in the numerical value of v L propagating in the wet gluten was found to be substantial (about 1,000 m/s) when the temperature of the gluten was raised from 20 to 90 °C, and also when gluten from different flour types was investigated. A continuous structural phase transition was observed, which was different for glutens extracted from different flours. Upon cooling, the velocity also varied depending on wheat type.These experiments demonstrate that ultrasonic velocity measurements can be used as a selection tool and study changes in properties of wheat proteins, particularly the thermal transitions that are critical to the quality of end products such as noodles, pasta, and bread. It was also shown that v L is sensitive to gluten class (strength or protein content), showing the potential of such measurements as an early-generation selection tool in wheat breeding programs.Sondare le proprietà termiche e strutturali di proteine di glutine che usano l’ultrasuono.Un nuovo approccio ultrasonico per caratterizzare la qualità di proteine di glutine di frumento è descritta. La frequenza bassa (50 kHz) la velocità longitudinale ultrasonica, ilAlla temperatura ambiente, ilQuesti esperimenti dimostrano che le misure di velocità ultrasoniche possono essere usate come uni cambiamenti di attrezzo di selezione e studio nelle proprietà di proteine di frumento, particolarmente le transizioni termiche che sono critico alla qualità di prodotti finiti come i sempliciotti, la pasta ed il pane. È stato anche mostrato che il

PurposeThe purpose of the paper is to study the effect of the gliadin and glutenin fractions of gluten on the cookie quality.Design/methodology/approachTen different wheat varieties were analyzed for the flour physicochemical characteristics, gluten composition and rheological properties. The different flours were baked into cookies. The cookies were analyzed for spread ratio and texture. Relationships of various flour parameters, gluten composition and cookie characteristics were determined.FindingsGluten subfractions, damaged starch, protein, AWRC values were significantly correlated to the cookie spread and texture. Damaged starch (r=−0.638), protein (r=−0.508) and AWRC (r=−0.844) had a negative relationship with the cookie spread. The flours with higher SDS sedimentation value also produced cookies with lower spread ratio and harder texture. The study clearly demonstrated a positive correlation between Gli:Glu ratio (r=0.765) and spread ratio and a negative correlation (r=−0.528) with hardness of the cookies measured in terms of breaking force. Flours with lower dough development time and dough stability performed better as cookie flours.Originality/valueThe gliadins and Gli/Glu ratio had a significant effect on the cookie spread and texture and the prediction equation developed during the study could accurately predict the cookie spread from the Gli/Glu ratio and AWRC values.

The gluten protein composition and expression level influence dough properties and are cultivar and environment dependent. To broaden the knowledge of the durum wheat gluten proteome, three cultivars were compared in two different growing seasons by a proteomic approach. Cultivar-specific and differentially expressed spots in the two years were identified by mass spectrometry. Significant differences were observed among the cultivars: Ofanto showed the lowest protein spot volumes in the high molecular weight (HMW) and low molecular weight (LMW)

Gluten proteins are major determinants of the bread making quality of wheat, but also of important wheat-related disorders, including coeliac disease (CD), and allergies. We carried out a proteomic study using the total grain proteins from two low-gliadin wheat lines, obtained by RNAi, and the untransformed wild type as reference. The impact of silencing on both target and on non-target proteins was evaluated. Because of the great protein complexity, we performed separate analyses of four kernel protein fractions: gliadins and glutenin subunits, and metabolic and CM-like proteins, by using a classical 2D electrophoresis gel based approach followed by RP-HPLC/nESI-MS/MS. As a result of the strong down-regulation of gliadins, the HMW-GS, metabolic and chloroform/methanol soluble proteins were over-accumulated in the transgenic lines, especially in the line D793, which showed the highest silencing of gliadins. Basing on these data, and considering that metabolic proteins and chloroform/methanol soluble proteins (CM-like), such as the α-amylase/trypsin inhibitor family, β-amylase and serpins, were related to wheat allergens, further in vivo analysis will be needed, especially those related to clinical trials in controlled patients, to determine if these lines could be used for food preparation for celiac or other gluten intolerant groups., [Biological significance] Several enteropathies and allergies are related to wheat proteins. Biotechnological techniques such as genetic transformation and RNA interference have allowed the silencing of gliadin genes, providing lines with very low gliadin content in the grains. We report a proteomic-based approach to characterize two low-gliadin transgenic wheat lines obtained by RNAi technology. These lines harbor the same silencing fragment, but driven by two different endosperm specific promoters (γ-gliadin and D-hordein). The comprehensive proteome analysis of these transgenic lines, by combining two-dimensional electrophoresis and RP-HPLC/nESI-MS/MS, provided a large number of spots differentially expressed between the control and the transgenic lines. Hence, the results of this study will facilitate further safety evaluation of these transgenic lines., The Spanish Ministry of Economy and Competitiveness (Projects AGL2013-48946-C3-1-R and AGL2016-80566-P), the European Regional Development Fund (FEDER) and Junta de Andalucía (Project P11-AGR-7920) supported this work. M.D. García-Molina thanks the Spanish Ministry of Economy and Competitiveness the granting of a PhD fellowship.

V svetu in v Sloveniji uporabljamo za hrano predvsem dve vrsti ajde, navadno ajdo (Fagopyrum esculentum) in tatarsko ajdo (Fagopyrum tataricum). Zanimanje za ajdo se je povecalo zaradi njene prehranske vrednosti. Za razliko od žit, pri katerih primanjkuje lizina, so beljakovine ajde zelo kakovostne, s primerno aminokislinsko sestavo glede na potrebe ljudi. Poleg kakovostnih beljakovin je pomembna vsebnost flavonoidov (rutina in kvercetina), vsebnost mineralnih elementov, prehranskih vlaknin, pa tudi zmožnost uspevanja v mejnih obmocjih kmetijske pridelave. Eden od razlogov za priljubljenost pridelovanja ajde je odpornost ajde proti patogenom in boleznim ter uspesno tekmovanje z rastjo plevelov. Torej je ajda primerna za ekolosko pridelovanje. Ajdovo zrnje nima glutena, zato je varno za ljudi s celiakijo, ki lahko uživajo le brezglutensko hrano. Uporaba zrnja in moke tatarske ajde v prehrani se v novejsem casu povecuje zaradi visoke vsebnosti rutina v primerjavi z navadno ajdo. Tatarsko ajdo so vsaj 200 let že pridelovali v Sloveniji, se je pa pridelovanje prenehalo v drugi polovici 20. stoletja. V nekaterih predelih Bosne in Hercegovine ter v mejnem obmocju Islek (severni Luksemburg, Westeifel v Nemciji in obmejno obmocje Belgije) so bila se nedavno edina obmocja v Evropi s pridelavo tatarske ajde za prehrano ljudi. V zadnjih desetih letih se pridelovanje tatarske ajde vraca tudi v Slovenijo. Ajda je pomembna rastlina v prehrani in pri prehranskih navadah v Sloveniji in prav tako v drugih državah srednje Evrope in Azije. V clanku je podan pregled podatkov v znanstvenih objavah, ki so pomembna izhodisca za raziskave vsebnosti flavonoidov, taninov in beljakovin v zrnju navadne in tatarske ajde. Kljucne besede: ajda, proteini, flavonoidi, zdravje, vrednotenje Two species of buckwheat are mainly used around the world and in Slovenia: common buckwheat (Fagopyrum esculentum) and Tartary buckwheat (Fagopyrum tataricum). The renewed interest in buckwheat is based on its nutritional value. Unlike cereals, which are deficient in lysine, buckwheat has excellent protein quality due to a balanced essential amino acid composition. Emphasised are the high protein quality, the concentration of flavonoids (rutin and quercetin), mineral elements and dietary fibre, and the ability to grow in marginal areas. One of the reasons for its popularity is the relative resistance of buckwheat to pest and diseases, and the ability to repress weeds. Buckwheat is thus suitable for ecological cultivation. It does not contain gluten proteins, so it is safe for people who require gluten-free diet (coeliac disease). Tartary buckwheat grain and flour are recently increasingly used in preparing dishes due to its even much higher content of rutin in comparison with common buckwheat. Tartary buckwheat has been cultivated to some extent in Slovenia for centuries, but this ceased before the end of the 20 th century. Some parts of Bosnia and Herzegovina, and the cross-border region Islek - which includes northern Luxemburg, the Westeifel, (Germany) and the border area of the of Belgium - was, not so long ago, the only places in Europe where Tartary buckwheat was still grown for humans. In the last 10 years, Tartary buckwheat has been returning to Slovenian fields. Buckwheat is an important plant and a dish in the cuisine and dietary habits of Slovenians and many other nations, including those of Central Europe and Asia. In the paper, based on the published scientific data, relevant starting points for the study and improvement of content of flavonoids, tannins and crude proteins in grain of common and Tartary buckwheat are presented. Key words: buckwheat, proteins, flavonoids, health, evaluation

The breadmaking quality of wheat is affected by the composition of gluten proteins and the polymerisation of subunits that are synthesised and accumulated in developing wheat grain. The biological mechanisms and time course of these events during grain development are documented, but not widely confirmed. Therefore, the aim of this study was to monitor the accumulation of gluten protein subunits and the size distribution of protein aggregates during grain development. The effect of desiccation on the polymerisation of gluten proteins and the functional properties of gluten were also studied. The results showed that the size of glutenin polymers remained consistently low until yellow ripeness (YR), while it increased during grain desiccation after YR. Hence, this polymerisation process was presumed to be initiated by desiccation. A similar polymerisation event was also observed when premature grains were dried artificially. The composition of gluten proteins, the ratios of glutenin to gliadin and high molecular weight-glutenin subunits to low molecular weight-glutenin subunits, in premature grain after artificial desiccation showed close association with the size of glutenin polymers in artificially dried grain. Functional properties of gluten in these samples were also associated with polymer size after artificial desiccation.

The size distribution assessment of unreduced wheat gluten proteins of commercial Indian wheat varieties was examined using Size-Exclusion Fast Protein Liquid Chromatography. Elution profiles were fractionated into five peaks, with the molecular weights of eluting peaks as 130–30, 55–20, 28–10 and

Celiac disease (CD) is an autoimmune enteropathy initiated and sustained by the ingestion of gluten in genetically susceptible individuals. It is caused by a dysregulated immune response toward both dietary antigens, the gluten proteins of wheat, rye, and barley, and autoantigens, the enzyme tissue transglutaminase (TG2). The small intestine is the target organ. Although routine immunochemical protocols for a laboratory diagnosis of CD are available, faster, easier-to-use, and cheaper analytical devices for CD diagnosis are currently unavailable. This review focuses on biosensors, consisting of a physicochemical transducer and a bioreceptor, as promising analytical tools for diagnosis of CD and other diseases. Examples of recently developed biosensors as well as expectations for future lines of research and development in this field are presented.

Unreduced gluten proteins of Indian wheat varieties viz.C306, DBW16, HI977 and HW2004 were separated using size-exclusion chromatography (SEC). Statistical correlation of area % of eluted peaks with properties of flour, dough and noodles was elucidated. Chromatograms of gluten proteins were classified primarily into five peaks in decreasing molecular size range and relative proportion were expressed in terms of area % of individual peaks which depicts the quantitative variation in protein eluted at different retention times. Cooking time and cooked weight of noodles depicted positive correlation with peak I and negative correlation with peak II which predominantly composed of glutenins and gliadins, respectively. Oil uptake and cooking loss were negatively association with peak I and positively with peak II. Noodle hardness, springiness, cohesiveness and chewiness were positively correlated with peak I and negatively to peak II, though adhesiveness was unaffected by SEC eluted peaks statistically.

Interactions between gluten proteins and dietary fiber supplements at the stage of bread dough formation are crucial in the baking industry. The dietary fiber additives are regarded as a source of polysaccharides and antioxidants, which have positive effects on human health. The fiber enrichment of bread causes a significant reduction in its quality, which is connected with changes in the structure of gluten proteins. Changes in the structure of gluten proteins and their thermal properties induced by seven commercial dietary fibers (fruit, vegetable, and cereal) were studied by FT-Raman spectroscopy and thermogravimetry (TGA), respectively. For this aim the bread dough at 500 FU consistency was made of a blend of wheat starch and wheat gluten as well as the fiber, the content of which ranged from 3 to 18% w/w. The obtained results revealed that all dietary fibers apart from oat caused similar changes in the secondary structure of gluten proteins. The most noticeable changes were observed in the regions connected with hydrogen-bonded β-sheets (1614 and 1684 cm(-1)) and β-turns (1640 and 1657 cm(-1)). Other changes observed in the gluten structure, concerning other β-structures, conformation of disulfide bridges, and aromatic amino acid microenvironment, depend on the fibers' chemical composition. The results concerning structural changes suggested that the observed formation of hydrogen bonds in the β-structures can be connected with aggregation or abnormal folding. This hypothesis was confirmed by thermogravimetric results. Changes in weight loss indicated the formation of a more complex and strong gluten network.

The functional properties of wheat are largely dictated by composition and interactions of the gluten proteins. All flours contain gliadin and glutenin, but produce baked products of varying quality, which provides evidence that gluten proteins from different wheats possess different properties. A common method to study differences in gluten properties, which is utilized in this study, is fractionation/reconstitution experiments to understand how various gliadin to glutenin ratios and how fractions from different wheat sources affect gluten aggregation properties. Gliadin and glutenin from a vital wheat gluten were fractionated with 70% ethanol and reconstituted at various gliadin to glutenin ratios. Gliadin and glutenin from a Canadian eastern soft, eastern hard and western hard wheat (14% moisture) were fractionated and substituted between flours at the native gliadin to glutenin ratio. Gluten combinations were evaluated with a Gluten Peak Tester at constant temperature and mixing. Varying gliadin to glutenin ratio showed that 50:50 is optimal for fast gluten aggregation while amount of glutenin dictates strength. Substitution experiments showed that replacing good quality gluten fractions with those from a lower quality wheat decreases gluten quality, and vice versa. Data also showed that cultivar specific differences in gliadin and glutenin are more important in dictating gluten strength (torque), while gliadin to glutenin ratio dictates aggregation time (PMT) independent of the source of fractions. The study demonstrated the ability of the improved method to evaluate gluten aggregation by controlling for all variables except the one being tested. The data also revealed information about gluten aggregation properties never before seen.

Green tea extract (GTE) was fortified into steamed bread as a functional ingredient to enhance its nutritional values. However, GTE might inhibit α-amylase activity and interact with gluten proteins, causing adverse effects on dough development and final loaf volume. This research investigated the effects of GTE and fungal alpha-amylase (FAA) on rheofermentometer characteristics, dough inflation parameters, and the specific volume of both dough and steamed bread. Rheofermentograph showed that the fortification of GTE did not affect the gassing power of yeast while it slightly inhibited the activity of FAA. Fortification of GTE at the level of 1.0 % decreased the dough inflation parameters and the specific volume of steamed bread. On the other hand, fortification of 60 ppm FAA enhanced the dough inflation parameters and increased the specific volume of steamed bread. Addition of 60 ppm FAA was able to fully compensate for the reduction of specific volume caused by the addition of 1.0 % GTE. Fortification of 0.50 % GTE produced steamed bread whose specific volume was not significantly different from that without GTE.

Wheat, one of the most important cereals, is grown on the largest area in Hungary. During hydration of storage proteins of wheat – gliadin and glutenin – the gluten complex is evolved. The gliadin is responsible for the extensibility of gluten complex as well as the glutenin for the strength of gluten. The structure, composition and rheological properties of gluten proteins influence significantly the baking quality. The gliadin/glutenin ratio and the quality and structure of glutenin fraction play the most important role in evolving gluten complex. Changes in the steps of breadmaking technology also have effect on the quality of product. Several tests proved that the higher glutenin content increases the strength of dough while the higher gliadin content increases the extensibility of dough and decreases maximum resistance to extension. The monomer gliadins play a great part in plasticity of glutenin polymer. The quality of glutenin fraction significantly influences the evolving gluten complex, because of the spiral structure of glutenin which deforms under stress conditions, then the β-spiral structure resumes their original conformation by releasing from stress.The final quality of product evolves as a result of complex characteristics of wheat proteins, so detailed knowledge on the roles of different protein compounds is the base of the quality oriented product development.

Lipids exhibit important functional properties in bread making, although they are present in lower levels than starch or protein. They originate from flour, in which they are endogenously present, or from added shortening and/or surfactants. This review discusses lipid sources and their interactions during the entire process of bread making from dough mixing to fermentation, proofing, baking and the stored product. The focus is on lipid interactions with starch and gluten proteins, their role in gas cell stabilisation and their impact on bread loaf volume, crumb structure and crumb firming. Widely accepted views on lipid functionality, although often opposing, are presented and critically discussed.

Wheat gluten is a widely used ingredient in the food industry due to its unique properties and relatively low price. Modification of wheat gluten makes it a versatile ingredient and, thus, increases its applicability in foods. Therefore, gluten proteins can be found in unexpected sources, and this makes the gluten-free diet challenging to follow. Deamidation is one way to modify protein structure. It increases solubility and surface activity of gluten improving its functionality, but consequently, also influencing the accuracy of quantification by immunoassays. In this study, the effect of deamidation on the antibody recognition with gluten analysis methods based on monoclonal R5, omega-gliadin or G12 antibodies was studied. Random deamidation decreased the intensities to 13–54% of the intensity obtained for the intact peptides. Deamidation representing the transglutaminase deamidation decreased the intensities to 4–8%. Deamidation of gluten proteins abolished the recognition by omega-gliadin and G12 antibodies and decreased the recognition of R5 by 600 times when analyzed by the sandwich method and 125 times by the competitive method. In conclusion, with all of the investigated gluten-specific antibodies, deamidation decreased the affinity of antibodies to gluten peptides and proteins, which needs to be considered when assays and regulations are developed for gluten-free products.

Celiac disease is a T-cell mediated immune response in the small intestine of genetically susceptible individuals caused by ingested gluten proteins from wheat, rye, and barley. In the allohexaploid bread wheat (Triticum aestivum), gluten proteins are encoded by multigene loci present on the homoeologous chromosomes 1 and 6 of the three homoeologous genomes A, B, and D. The effect of deleting individual gluten loci was analyzed in a set of deletion lines of T. aestivum cv. Chinese Spring with regard to the level of T-cell stimulatory epitopes (Glia-α9 and Glia-α20) and to technological properties of the dough including mixing, stress relaxation, and extensibility. Deletion of loci encoding ω-gliadins, γ-gliadins, and LMW-glutenins located on the short arm of chromosome 1D, reduced the number of T-cell stimulatory epitopes and caused minor deterioration of dough quality by increase of elasticity. Deletion of loci encoding α-gliadins located on the short arm of chromosome 6D, resulted in a significant decrease in T-cell stimulatory epitopes. In parallel, the dough became more stiff and less elastic, which is an improvement for ‘Chinese Spring’ dough. We demonstrated that α-gliadins from wheat can largely be compensated by addition of avenins from oat to the flour to meet technological requirements.

Changes in expression and accumulation of gluten proteins were investigated in developing kernels of 2 wheat cultivars, Norin 61 and Fukusayaka. Expression of 7 gluten subunit genes was detectable 7 days after anthesis (DAA) in both cultivars, while changes in expression patterns of these subunits over time were found to be specific to each cultivar. The accumulation of total proteins and ethanol-soluble proteins was analysed by SDS-PAGE and acidic-PAGE, respectively. The band patterns of total proteins in both cultivars changed markedly between 14 and 21 DAA. Ethanol-soluble proteins, which are mainly gliadin proteins, were detected at 21 DAA in Norin 61 and at 14 DAA in Fukusayaka. We investigated the textural properties of dough prepared from the flour of mature and immature Norin 61. The tension test revealed that dough prepared from immature wheat had higher tensile strength and lower extensibility than that prepared from mature wheat.

Coeliac disease (CD) is a long-life intolerance to gluten proteins, with prevalence of 1–2% worldwide and health consequences if not treated. Currently, the treatment is the dietary gluten withdrawal, but commercial gluten-free foodstuffs present undesirable properties. Therefore, attempts are being made to modify the immunogenic sequences of gluten to avoid recognition by the immune system and to prepare safe and acceptable foods. These include long-time fermentation by sourdough and enzymic modification. The present article reviews our current knowledge of the pathogenesis of CD and the advantages and limitations of the current approaches to gluten modification and to develop safer foods for CD patients.

Gluten proteins from wheat can induce celiac disease (CD) in genetically susceptible individuals. Specific gluten peptides can be presented by antigen presenting cells to gluten-sensitive T-cell lymphocytes leading to CD. During the last decades, a significant increase has been observed in the prevalence of CD. This may partly be attributed to an increase in awareness and to improved diagnostic techniques, but increased wheat and gluten consumption is also considered a major cause. To analyze whether wheat breeding contributed to the increase of the prevalence of CD, we have compared the genetic diversity of gluten proteins for the presence of two CD epitopes (Glia-α9 and Glia-α20) in 36 modern European wheat varieties and in 50 landraces representing the wheat varieties grown up to around a century ago. Glia-α9 is a major (immunodominant) epitope that is recognized by the majority of CD patients. The minor Glia-α20 was included as a technical reference. Overall, the presence of the Glia-α9 epitope was higher in the modern varieties, whereas the presence of the Glia-α20 epitope was lower, as compared to the landraces. This suggests that modern wheat breeding practices may have led to an increased exposure to CD epitopes. On the other hand, some modern varieties and landraces have been identified that have relatively low contents of both epitopes. Such selected lines may serve as a start to breed wheat for the introduction of ‘low CD toxic’ as a new breeding trait. Large-scale culture and consumption of such varieties would considerably aid in decreasing the prevalence of CD.