Gluten Extensibility Research Articles

Stabilization of consumer characteristics of bread made from wheat flour with reduced baking properties

The article aims to study the issue of improving the baking properties of wheat flour. This is an urgent task because, according to the agrarians, regardless of the amount of the harvested crop, there are problems with the grain quality. An analysis of the causes of problems with grain and flour was carried out, and ways of solving them from the point of view of bakers were considered. Quality control was carried out for batches of high-grade wheat flour. One sample with low baking properties, namely weak gluten, was selected. Since the gluten frame is the basis for the retention of carbon dioxide in the dough and ensures the formation of pore walls and the shape of bakery products, attention was paid to the conditions of the technological process and the recipe composition of the products, which would contribute to obtaining high-quality products. The possibility of using existing food additives was analyzed to improve the quality indicators of flour semi-finished products and finished products. It was proposed to use an improver of plant origin – fruit and vegetable concentrate. Its positive effect on the elasticity and extensibility of gluten has been established. The optimal dosage of the additive was selected, for which bread with acceptable volume, dimensional stability, porosity, and taste was obtained – 25 % of the flour mass. It has also been established that using this additive allows you to speed up the bread production process. In addition, the concentrate enriches bread with organic acids, biologically active substances that are part of carrots and apples, thereby increasing the nutritional value of bread. It has also been established that using this additive allows you to speed up the bread production process. In addition, the concentrate enriches bread with organic acids, biologically active substances that are part of carrots and apples, thereby increasing the nutritional value of bread.

Incorporation of intermediate wheatgrass (Thinopyrum intermedium) into bread wheat doughs: Effects on pasting and rheological properties

AbstractBackground and ObjectivesIntermediate wheatgrass (IWG), a resilient perennial grain with adaptability to difficult climates, is emerging as a compelling candidate for sustainable food solutions in bakery product applications. This study evaluated the pasting and rheological properties of doughs made from bread wheat flour and blended bread wheat–IWG flours (IWG content: 15%, 30%, 45% and 60%), with the goal of exploring the potential of IWG flour as a nutritious and sustainable ingredient in cereal‐based products.FindingsThe RVA peak, trough, and final viscosity values significantly (p < .05) decreased, and the pasting temperature increased as the IWG substitution level increased. IWG‐containing flour blends had a lower retrogradation tendency compared to the control. As the IWG flour substitution level increased, both empirical (Mixograph, Kieffer dough and gluten extensibility, Glutograph) and fundamental (linear oscillatory frequency sweep and creep–recovery) rheological measurements indicated relatively weaker dough properties imparted by the addition of the IWG flour.ConclusionsThe outcomes of this research will shed light on the impacts of utilizing alternative grains, such as intermediate wheatgrass, in bakery applications. This will provide insights that could inform the development of nutritious and sustainable baked products to meet the demands of health‐conscious consumers.Significance and NoveltyThe dough weakening effect of the IWG flour was tolerated at the 15% IWG flour substitution level. At lower substitution levels, the IWG‐containing flour blends exhibited a lower retrogradation tendency compared to bread wheat flour, which could indicate lower staling of loaves of bread during bread storage without compromising the physical quality of bakery products. Finally, the present research fills a critical gap in the literature as it represents the first application of fundamental rheological methods at known and controlled strain and stresses to evaluate the physical properties of doughs prepared from IWG flour blends.

Processing and Bread-Making Quality Profile of Spanish Spelt Wheat.

Spelt wheat (Triticum aestivum L. ssp. spelta Thell.) is an ancient wheat that has been widely cultivated for hundreds of years. Recently, this species has been neglected in most of Europe; however, the desire for more natural and traditional foods has driven a revival of the crop. In the current study, eighty-eight traditional spelt genotypes from Spain, together with nine common wheat cultivars and one modern spelt (cv. Anna Maria) were grown during a period of two years in Andalucia (southern Spain). In each, several traits were measured in to evaluate their milling, processing, and end-use quality (bread-making). The comparison between species suggested that, in general, spelt and common wheat showed differences for most of the measured traits; on average, spelt genotypes had softer grains, higher protein content (14.3 vs. 11.9%) and gluten extensibility (alveograph P/L 0.5 vs. 1.8), and lower gluten strength (alveograph W 187 vs. 438 × 10-4 J). In the baking test, both species showed similar values. Nevertheless, the analysis of this set of spelt genotypes showed a wide range for all measured traits, with higher values than common wheat in some spelt genotypes for some traits. This opens up the possibility of using these materials in future breeding programs, to develop either new spelt or common wheat cultivars.

Improving the quality of wheat bread by enriching teff flour

The research of the influence of teff flour on the technological process and quality of wheat bread was present in the article. The analysis of the chemical composition of teff flour indicated, that it is a valuable raw material for enriching wheat bread. However, its dosage in the quantity of 10 and 20 % to the weight of wheat flour leads to decrease in the amount, springy and extensibility of gluten in the dough. Alveograph studies also confirmed that dosage of 20 % of teff flour the most decreases springy of the dough and it becomes more plastic. The improvement of the structural and mechanical parameters of bread with teff was applied the biotechnological method of preparation on sourdough that created on the pure cultures of lactic acid bacteria “Biolight”. The experimental studies were proving that utilizing of teff flour in the quantity of 10 % and sourdough improved both the quality and nutritional value of wheat bread. In particular, the specific volume of bread increased by 4.0 %, acidity ‒ by 2.9 % compared to the control; and the product was distinguished by a pleasant "nutty" taste and aroma. Close correlations between the percentage of teff addition and the spread of the dough ball were established, r=0.98 (n=10, p≤0.05) and the form stability of the bread, r=(‒0.95) (n=10, p≤0.05). It allowed establish that wheat bread with teff addition need to make in the mould. It was calculating that consumption of the daily norm of bread with 10% teff the consumer will be receiving a sufficient quantity of valuable food nutrients. Thus, the need of protein was covered by 42.9 and 49.8 %; iron ‒ by 32.3 and 28.5 %; vitamin B5 ‒ by 17.6 and 24.2 %, respectively, for men and women; and the need for phosphorus ‒ by 26.7 %, for both groups. The technology of wheat bread with teff of high quality for mass consumption that recommended for wide industrial implementation has been develop

Characterization and regeneration potential of vital wheat gluten treated with non-thermal plasma

Non-thermal plasma (NTP) technology is an emerging physical process that has attracted the interest of researchers owing to its promising effects in food processing. This study aimed to determine the effect of NTP treatment at atmospheric pressure on vital wheat gluten (VG) properties. VG treated at powers of 50 W, 100 W, and 150 W and flow rates of 3, 5, and 8 L/min was characterized, and the empirical rheology of flours enriched with these VGs was determined. NTP promoted greater water absorption capacity, higher wet gluten content, and gluten index, and greater resistance to extension when 50 W and 5 L/min were applied. When power and flow rate were increased, resistance to extension decreased, and gluten extensibility increased. Under optimal VG treatment conditions, the rheological properties of the enriched wheat flours revealed an improvement in the development time and stability of dough. Based on the results obtained with the power and flow rate ranges tested herein, NTP can be used to modulate the functionality of VG.

Heat mediated physicochemical and structural changes of wheat gluten in the presence of salt and alkali

To understand the heat mediated cross-linking mechanism of gluten in the presence of salt and alkali, the effects of heating on the physicochemical and structural changes of gluten protein was comparatively investigated in this study. Our results showed that the G′ value of gluten was mediated by heating, while alkali delayed the transition temperature by approximately 20 °C. Salt increased the extensibility of gluten. However, alkali improved gluten strength and toughness. Fluorescence spectroscopy, surface hydrophobicity, and AFM images demonstrated that hydrophobic interactions and aggregations of protein molecular chains were enhanced by both salt and alkali, and heating further promoted these interactions. In addition, alkali reduced the aggregation temperature of large glutenin polymers from 95 to 75 °C according to SE-HPLC profiles. RP-HPLC patterns confirmed that α- and γ-gliadin subunits were more susceptible to heat and polymerized after heating at 95 °C with alkali. QCM-D results showed that alkali promoted protein-protein interactions in gluten, which was positively correlated with temperature. This study consummates the understanding of heating mediated cross-linking mechanisms of gluten with salt and alkali and provides a more comprehensive theoretical basis for the control of gluten properties and quality of wheat products.

The effects of Cephalaria syriaca flour on physical, rheological and textural properties of sunn pest (Eurygaster integriceps) damaged wheat dough and bread

The aim of this study was to investigate the effects of Cephalaria syriaca flour (CSF; 0.5, 1.0 and 1.5%) on the physical, textural and rheological characteristics of dough and bread obtained from sunn pest-damaged wheat (SPDW; 5, 10 and 15%). An increased CSF level significantly decreased the stickiness and volume loss values of dough and the firmness and chewiness values of bread for all SPDW levels. The dough stickiness and bread firmness values were considerably increased by the addition of SPDW at the 15% level (1.05 N and 29.76 N), whereas these values were reduced by the addition of 1.5% CSF (0.6439 N and 22.56 N). In general, the stress relaxation, gas retention and gluten extensibility parameters of dough; and the specific volume, colour, cohesiveness, springiness and resilience values of bread significantly increased depending on the increasing level of CSF. Especially, the 1.5% CSF level significantly improved the quality of the dough and breads. The results of the present study revealed that CSF addition to SPDW flour positively affected the stickiness, gas retention and stress relaxation of dough and the specific volume and instrumental textural properties of bread.

Persimmon tannin changes the properties and the morphology of wheat gluten by altering the cross-linking, and the secondary structure in a dose-dependent manner

The effects of persimmon tannin (PT) on the texture, viscoelasticity, thermal stability, and morphology of gluten were studied and the underlying mechanisms were also explored. The results showed that PT increased the hardness and viscoelasticity but lowered the cohesiveness and extensibility of gluten in a dose-dependent manner. Additionally, PT increased the denaturation temperature and enthalpy of gluten, and induced the formation of gluten with compact structure. High concentration of PT (8%) significantly increased the hardness and viscoelasticity of gluten, and induced the formation of compact structure of gluten by disturbing the conformation of gluten, and interfering gluten cross-linking through decreasing disulfide bonds, free sulfydryl groups, and free amino groups. In contrast, low concentration (0.25%) of PT slightly altered the gluten properties and morphology. Our work extended the study on the supplementation of phenolic compounds in wheat flour-based products.

Rheology Methods as a Tool to Study the Impact of Whey Powder on the Dough and Breadmaking Performance of Wheat Flour

Considering the nutritional value, whey is an excellent ingredient for the development of food products, in line with the concept of a circular economy for the reuse of industry by-products. The main objective of this work was to evaluate the impact of the whey addition on the rheology of wheat flour dough and breadmaking performance, using both empirical and fundamental methods. Different levels of commercial whey powder (0%, 12%, 16% and 20% w/w) were tested in a bread formulation previously optimized. Dough mixing tests were performed using Micro-doughLab and Consistograph equipment, to determine the water absorptions of different formulations and evaluate empirical rheology parameters related to mixing tolerances. Biaxial extension was applied by the Alveograph to simulate fermentation during the baking process. Fermented doughs were characterized in a Texturometer using penetration and extensibility tests, and by small amplitude oscillatory shear (SAOS) measurements, a fundamental rheology method, in a Rheometer applying frequency sweeps. Loaf volume and firmness were used to study the breadmaking quality. Despite a negative impact on the empirical rheology parameters of the dough and poorer baking results, the use of this by-product should be considered for nutritional and sustainability reasons. In addition, significant correlations (r2 > 0.60) between the dough rheology parameters obtained from the empirical measurements were established. Changes in the gluten structure were not accurately detected by the SAOS measurements and Texture Profile Analysis of the doughs, and a correlation between fundamental and empirical measurements was not found. Consistograph or Micro-doughLab devices can be used to estimate bread firmness. Extensional tests in the Texturometer, using SMS/Kieffer Dough and Gluten Extensibility Rig, may predict loaf volume.

Preliminary characterization for grain quality traits and high and low molecular weight glutenins subunits composition of durum wheat landraces from Iran and Mexico

Durum wheat landraces from Iran and Mexico were evaluated for important grain traits, gluten quality characteristics and ultimate baking performance. It was also characterized by SDS-PAGE for high and low molecular weight glutenins composition. Substantial phenotypic variation was observed for most traits, with promisingly useful variability identified for attributes that typically limit durum wheat from being used in industrial bread-making processes, such as gluten extensibility and actual baking performance. Promising genotypes with atypically enhanced extensibility and/or baking performance, independently, from high protein content were identified and can be considered as valuable parental stocks to be exploited in durum breeding programs targeting the widening of the end-uses of this grain. A significant number of novel glutenins subunit and/or subunit combinations were described. The Iranian group was found to be more diverse than the Mexican group, which is consistent with their respective evolution histories: The Mexican Creoles wheats represents a small sample of the variability that was present in the Iberian Peninsula when they were moved to Mexico while the Iranian landraces evolved very close to the center of Origin of durum wheat, maintained most of the variability that was developed in the region from the early days of durum wheat evolution.

Cloning and characterization of high molecular weight glutenin gene from Triticum aestivum cultivar Dacke

<p class="abstract"><strong>Background:</strong> High molecular weight (HMW) glutenin protein plays a crucial role in determining dough viscoelastic properties that determines the quality of wheat flour. The aim of the present study was to isolate, clone and analyze (<em>in silico</em>) the HMW glutenin gene of <em>Triticum aestivum</em> cultivar Dacke.</p><p class="abstract"><strong>Methods:</strong> Primers were designed to amplify a 2445 bp fragment of HMW glutenin gene. Ax type HMW glutenin gene from <em>Triticum aestivum</em> cultivar Dacke was isolated using PCR and it was sequenced by primer walking. </p><p class="abstract"><strong>Results:</strong> Amplified HMW glutenin gene was designated as HMWGAx. Sequence analysis revealed a complete open reading frame encoding 815 amino acid residues with N- and C terminal non-repetitive domain and a central repetitive domain. The calculated molecular weight of the deduced HMW glutenin protein was ~88 kDa and the number of cysteine residues in the HMWGAx was four, in accordance with other x type HMW glutenin proteins. Phylogenetic analysis revealed 100% homology to the previously studied Ax2* type HMW glutenin gene from cultivar Cheyenne. Predicted secondary structure results showed that it was similar to1Ax1 type of common wheat (<em>Triticum aestivum</em>), having superior flour milling quality.</p><p><strong>Conclusions:</strong> Sequence analysis suggests that HMWGAx protein significantly and positively correlates with the properties of elasticity and extensibility of gluten. </p>

The physiochemical properties and shelf-life of orange-fleshed sweet potato puree composite bread.

Value addition of orange‐fleshed sweet potato (OFSP) increases diversified utilization of this crop, which is rich in provitamin A carotenoids. OFSP bread, in which 30%–45% of wheat flour is replaced with OFSP puree, has been successfully commercialized in Kenya. However, the effect of this substitution on the bread's physiochemical properties and its shelf‐life are currently unknown. This study was designed to determine the physiochemical properties and shelf‐life of OFSP puree‐wheat flour composite bread (30% puree), compared to standard, 100% wheat flour, bread. Freshly baked bread samples were stored at 7, 20, 25, and 30°C, and monitored for moisture content, water activity, color, texture, volume, carotenoids, and microbial load. The moisture content, β‐carotene content, and color of bread significantly decreased with increase in storage temperature and time (p < 0.05). Bread made with OFSP puree had a longer shelf‐life, showing spoilage on day six compared with the white bread, which spoiled on the fourth day. This is attributed to the significantly higher water activity in white bread than in the OFSP bread. The substitution of wheat with OFSP puree resulted in reduced extensibility of gluten, thus, specific volume of white bread was significantly (p < 0.05) higher than that in OFSP puree bread. Refrigeration increased crumb firmness, chewiness and cohesiveness in both types of bread. In conclusion, OFSP puree increases the water binding capacity of the bread, which reduces water activity and increases its shelf‐life.

How leaf rust disease and its control with fungicides affect dough properties, gluten quality and loaf volume under different N rates in wheat

The unique viscoelastic properties of gluten make bread wheat (Triticum aestivum L.) a staple food. The specific balance between gluten fractions, together with grain protein content (GPC), defines nutritional and end-use properties. The leaf rust (Puccinia triticina Eriks.) and its control using succinate dehydrogenase inhibitors (SDHIs) fungicides together with nitrogen (N) fertilization could alter the GPC and its composition during the grain-filling period, modifying dough properties. The aim of this study was to investigate the effects of leaf rust, its control using fluxapyroxad (SDHI) and the interaction with N fertilization on breadmaking quality of wheat. Two field experiments were conducted during 2014 and 2015 in a split-split plot design with three fungicide treatments as main plots and three N fertilization rates as subplots using a susceptible cultivar. Leaf rust reduced GPC and modified its composition. The disease shortened the grain-filling period and reduced gluten content. Gluten tenacity (AlvP) was more affected than gluten extensibility (AlvL) resulting in doughs with lower AlvP/L ratio, minor gluten strength and inferior loaf volume. The treatment containing fluxapyroxad showed better levels of disease control and it also evidenced additional beneficial effects in most of the evaluated parameters compared to the treatment without this active ingredient.

Enhancing dough-making rheological performance of wheat flour by transglutaminase and vital gluten supplementation

The aim of this study was to optimize dough formulation using flours of different strength, through the supplementation of different levels of transglutaminase (TG) and vital gluten (VG). For this purpose, the experimental design took into consideration different factors including 3 different flour strengths (weak, medium and strong), 4 levels of TG (0, 0.05, 0.1 and 0.2% of flour weight), two levels of VG (0 and 1% of flour weight) and 4 different resting times (45, 70, 90 and 135 min). The rheological behavior of the obtained doughs was assessed using the SMS/Kieffer Dough and Gluten Extensibility Rig fitted to a texture analyzer. Multivariate analysis showed that dough resistance (R) and extensibility (E) were significantly (p ≤ 0.05) affected by all the studied factors, particularly flour strength and resting time. Considering data analysis results, the combinations enabling an increase in R for each flour type were identified: for strong flour (RT = 45min, TG = 0.2%, VG = 1%), medium flour (RT = 45min, TG = 0.1%, VG>1%) and weak flour (RT = 45min, TG>0.2%, VG>1%). Overall, results indicated that even low supplementation of TG and VG changed dough rheological quality of the flours strongly, suggesting further work to assess their influence on bread-making quality.

Optimization of micro-scale extension tests for wheat dough and wet gluten

Micro-scale extension tests to determine the viscoelastic properties of wheat dough and wet gluten based on 10 g of flour each are useful methods to predict baking performance, but there is no official standard method. The experimental procedure was optimized by varying rest periods and test speeds and the results were evaluated considering repeatability, discrimination of different samples and duration of analysis. In both tests, dough was prepared by mixing to the respective optimum consistency followed by a 15 min rest period at 22 °C and measurement at a test speed of 3.3 mm/s for dough. For wet gluten, the subsequent steps involved removal of starch by washing, centrifugation of the gluten strands (3060 × g, 10 min, 22 °C), resting for 30 min at 22 °C and measurement using the same test speed (3.3 mm/s) with the SMS/Kieffer Dough and Gluten Extensibility Rig fitted to a texture analyzer. Correlation analyses revealed, inter alia, that the maximum resistance to extension and the area under the curve of wet gluten extension tests were suitable to predict micro-rapid-mix test loaf volumes. In combination with the micro-scale extension test for rehydrated vital wheat gluten, these methods are deemed suitable for international validation.

Milling, processing and end-use quality traits of CIMMYT spring bread wheat germplasm under drought and heat stress

The CIMMYT wheat breeding program aims to develop bread wheat (Triticum aestivum L.) genotypes that have superior grain yields, disease resistance and stress tolerance, along with appropriate quality to satisfy all stakeholders of the wheat value chain. Grain quality for wheat consists of a combination of many defined parameters including grain morphological characteristics, dough and final products properties, all of which are defined by the genotype, the environment and their interactions. Our current approach for improving grain quality is to study grain samples obtained under high yield potential environments with optimum management. To assess the effect of this strategy on quality under stressed environments, 54 genotypes were evaluated for two years under six environmental conditions, including drought and heat stress. Grain morphology (grain density and size), protein content and flour yield were severely affected by the environment, as drought and heat stress had a strong negative effect on all of these characteristics except protein content. Gluten quality (strength and extensibility) was defined more by the genotype, although the environmental effects and the interactions were also important, particularly for gluten extensibility. The current selection strategy for quality traits carried out under optimum conditions was found to be suitable to ensure high quality characteristics across several environments for most of the parameters with an overall positive outcome.

Structural properties of gluten modified by ascorbic acid and transglutaminase

ABSTRACTThe effect of transglutaminase (TG) and ascorbic acid (AA) on the physicochemical properties of gluten was studied. The results showed that TG increased the gluten yield, storage modulus, and particle size distribution by forming a G-L bond in the protein structure. TG changes the three-dimensional structure of gluten by forming a G-L bond in the protein chains and partly preventing disulfide bond formation. However, in the high concentration of the enzyme, by reducing the ratio of lysine to glutamine, TG catalyzes the deamidation of glutamine residues and thus the K′, gluten yield, and particle size decrease significantly. The rheological behavior of glutenin macropolymer (GMP) gel was changed and the gluten extensibility increased. AA leads to an improvement in the aggregation of gluten and increases the particle size distribution. The results showed that AA leads to an increase in the disulfide bond formation and the strength of the gluten network. Adding AA reduced the delta value and increased G’ compared with the control.

Genetic improvement of grain quality traits for CIMMYT semi-dwarf spring bread wheat varieties developed during 1965–2015: 50 years of breeding

The Global Wheat Program, now managed by the CGIAR consortium and led by CIMMYT, initiated wheat breeding about 70 years ago in Mexico. Currently, the key objectives are to develop wheat cultivars that have superior grain yield, durable disease resistance, drought and heat tolerance and meet the processing and end-use quality needs for diverse worldwide processing conditions and products. In this study, the genetic gains in grain quality of semi-dwarf spring wheat cultivars developed from 1965 to 2015 by CIMMYT and related breeding programs of national partners in the target areas were examined. Genetic gains for test weight, thousand kernel weight, grain hardness, flour yield, gluten extensibility and protein content were non-significant, and these traits remained stable despite grain yield increase over years. Positive genetic gains were found for dough strength related parameters mixograph mixing time (0.026min. per year), torque (0.93 per year) and alveograph W (2.31J*10–4 per year), and bread-making quality (loaf volume, 1.32mL per year). We concluded that genetic gains for grain yield of CIMMYT spring wheat cultivars demonstrated by previous studies were not at the expense of processing and end-use quality traits. Both types of traits have been improved in the last 50 years through direct selection ensuring the acceptability of CIMMYT germplasm in the target countries by all wheat value chain stakeholders.

Rheological properties and microstructure of xylanase containing whole wheat bread dough.

The present research work was undertaken to investigate the effect of xylanase, produced by Penicillium citrinum, on rheological behavior of whole wheat bread dough at large and small deformation respectively. Dough attributes including textural properties (penetration) and structure related characteristics (oscillatory tests) were evaluated. Change in visco-elastic properties of xylanase containing dough was evaluated by oscillatory and creep measurements. The flow experiments were conducted under steady-state condition with shear rate ranging from 0.01 to 100s-1. Frequency sweep experiments were performed between 0.01 and 10Hz. It revealed that in both control and xylanase containing dough formulation, the elastic modulus was higher than viscous modulus in the entire range of frequency. Our results represent the adequacy of fitting of dynamic moduli in Power law model and week gel model. Peleg model as well as six element Kelvin model described well the creep behaviour of control and xylanase-containing dough. Uniaxial extensibility was assessed by Kieffer dough and gluten extensibility rig. Lyophilized powder of untreated and xylanase treated doughs were tested under scanning electron microscope. FTIR spectra of lyophilized powder of untreated and xylanase treated dough were recorded in the range of 600-4000cm-1.

Effect of Condensed Tannin Profile on Wheat Flour Dough Rheology.

Proanthocyanidins (PA) cross-link proteins and could expand wheat gluten functionality; however, how the PA MW or gluten profile affect these interactions is unknown. Effect of PA MW profile (sorghum versus grape seed PA) on dough rheology of high versus low insoluble polymeric protein (IPP) wheat flour was evaluated using mixograph, large (TA.XT2i) and small (HAAKE Rheostress 6000) deformation rheometry. Sorghum PA (93% polymeric) more effectively (p < 0.05) strengthened both glutens than grape seed PA (45% polymeric), without reducing gluten extensibility. These effects were higher in low IPP (weak gluten) flour, e.g., sorghum PA doubled IPP, increased mix time by 75%, dough elasticity by 82%, and peak angle by 17° versus control. Grape seed PA increased IPP by 75% and elasticity by 36%, but reduced peak angle by 15°, indicating reduced mixing tolerance. Sorghum PA, but not grape seed PA, increased (p < 0.05) all above parameters in high IPP dough. Polymeric PA more effectively strengthened gluten than oligomeric PA, likely via more efficient protein cross-linking to overcome strong antioxidant effect of PA. High MW PA may be useful natural gluten strengtheners for diverse applications.