Gluten Dough Research Articles

Water-assisted extrusion of carbon fiber-reinforced wheat gluten for balanced mechanical properties

Plasticizers turn brittle bio-based and biodegradable highly hydrophilic polymers into tough materials. Unfortunately, it also means that the material becomes softer and weaker. The concept of combining a plasticizer and reinforcing fibers was investigated here on a protein material (wheat gluten) plasticized with glycerol and reinforced with chopped carbon fibers. The carbon fibers showed good interfacial bonding with the gluten matrix and improved both tensile strength and Young’s modulus of the material. The resulting composites also showed reduced elongation at break but still underwent ductile fracture under tension. Water-assisted extrusion, where water was used as a processing aid, was used to manufacture the composites and boost the reinforcement. Water addition significantly reduced the viscosity of the gluten dough and thus decreased fiber breakage during extrusion/compounding. The composites prepared with water-assisted extrusion had much longer fibers and consequently higher stiffness than those prepared without water. Apart from the balanced mechanical properties, the resulting composites showed reduced uptake of moisture (reduced moisture sensitivity) due to the water-impermeable carbon fibers. Hence, a new extrusion method was presented for fiber-reinforced inherently viscous plant-based polymer composites, which enabled good mixing without critical fiber damage and thus improved fiber reinforcement.

Effects of a commercial peptidase on rheology, microstructure, gluten properties of wheat dough and bread quality

Flavourzyme is a commercial peptidase, mainly with exopeptidase activity. In this study, effects of Flavourzyme addition (0–0.16 g/100 g) on properties of wheat dough and bread were systematically studied. Bread with a low concentration (0.01–0.08 g/100 g) of Flavourzyme addition had a large specific volume and soft texture with a uniform cell structure. The optimal Flavourzyme content was 0.04 g/100 g and the specific volume increased from 3.9 mL/g to 4.4 mL/g, the hardness decreased from 21.7 N to 13.3 N. The gas production capacity of yeast increased with low concentrations of Flavourzyme addition, promoting dough expansion. Flavourzyme had a clear hydrolysis effect on wheat gluten in dough and caused the depolymerization and unfolding of gluten structure, thus decreasing the strength and viscoelasticity of dough. Confocal laser scanning microscopy and scanning electron microscopy results further revealed that a low concentration of Flavourzyme had a slight effect on gluten. However, the gluten structure became discontinuous and open, which made the dough easily collapsed during fermentation, resulting in poor bread quality with high Flavourzyme content. The positive effects of appropriate amount of Flavourzyme addition on dough and bread properties indicated the potential of Flavourzyme as a bread improver by substituting chemical additives.

Comparison of quality characteristics of six reconstituted whole wheat flour with different modified bran

The effects of six bran modification treatment (microwaving, steam, extrusion, enzymolysis, fermentation and superheated steam) on the quality characteristics of reconstituted whole wheat flour were compared. As shown by the results, the treatments modified the physicochemical and pasting property, dynamic rheology, mixing characteristics, intermolecular forces and secondary protein structure of the reconstituted flour. The peak viscosity and final viscosity after microwaving were the highest, at 2528.00 and 3154.33 cp, respectively. The tanδ values after fermentation, superheated steam and microwaving were higher than control, indicating improved flour processing quality. Enzymolysis resulted in the longest dough stability time and the shortest dough formation time, as well as the highest disulfide bridge content and ionic bond force in the dough gluten component, which would strengthen the dough gluten network. Microwaving resulted in the highest β-sheet content and the weakest hydrophobic interactions in the gluten, which would also strengthen the dough gluten network. Overall, enzymolysis produced the greatest strengthening of gluten network and improvement in dough rheological properties. These findings advance the understanding of the molecular mechanisms underlying the effects of the bran treatments and will aid future optimization of industrial bran modification.

Interaction between A-type/B-type starch granules and gluten in dough during mixing

To explore the interaction between A/B starch and gluten, the rheological and structural properties of starch-gluten dough with varied A/B starch ratios during mixing were investigated. The G′ and G″ values of under- and overdeveloped dough with an A/B starch ratio of 5:5 were higher than those of dough with other ratios and decreased as the A/B starch ratio increased in optimized dough. B starch enhanced extension resistance and dough firmness. Small B starch granules promoted continuous gluten network formation, while large A starch granules readily separate from the gluten network. B starch promoted GMP polymerization. Covalent bonds were the main force involved in A starch-gluten interactions. Hydrophobic interactions were the main force in the under- to optimum-mixing stages, whereas hydrogen and covalent bonds were involved in B starch-gluten interactions from the optimum- to over-mixing stages. A model describing the interactions between gluten and starch components was proposed.

Combined effect of NaCl and resting on dough rheology of Chinese traditional hand‐stretched dried noodles and the underlying mechanism

AbstractBackground and objectivesChinese traditional hand‐stretched dried noodles (CHDN) have been a staple for thousands of years in China and are increasing popular worldwide. NaCl and resting play key roles in the production of CHDN. This study was designed to investigate the combined effect of salt addition and resting on rheology of CHDN dough.FindingsThe results of our study showed that the storage modulus (G′), loss modulus (G″), Tanδ, and extensional property of dough increased with the increased levels of NaCl and peaked at 4% NaCl. These changes were due to that salt promoted the aggregation of gluten in dough by increasing the hydrogen bonds and hydrophobic interactions among gluten subunits. The resting process resulted in decreased G′, G″, and extensional strength, while it increased Tanδ, extensibility, and the extensional area, and these were caused by gluten relaxation and gliadin aggregation. The increased addition of NaCl accelerated the change in small deformation rheology of dough during resting but decelerated the change in extensional property.ConclusionsIncreased salt additions could increase the extensibility and extensional strength of rested dough and extend the changing time in extensional property of CHDN dough during resting. In conclusion, increased salt addition would enhance the processing property and extend the resting time of dough during the production of CHDN.Significance and noveltyThe combined effect of NaCl addition and resting on the rheology of the dough for CHDN preparation and the underlying mechanisms were investigated. This study provides insights into the production of CHDN.

Effects of Physical and Chemical Factors on the Structure of Gluten, Gliadins and Glutenins as Studied with Spectroscopic Methods.

This review presents applications of spectroscopic methods, infrared and Raman spectroscopies in the studies of the structure of gluten network and gluten proteins (gliadins and glutenins). Both methods provide complimentary information on the secondary and tertiary structure of the proteins including analysis of amide I and III bands, conformation of disulphide bridges, behaviour of tyrosine and tryptophan residues, and water populations. Changes in the gluten structure can be studied as an effect of dough mixing in different conditions (e.g., hydration level, temperature), dough freezing and frozen storage as well as addition of different compounds to the dough (e.g., dough improvers, dietary fibre preparations, polysaccharides and polyphenols). Additionally, effect of above mentioned factors can be determined in a common wheat dough, model dough (prepared from reconstituted flour containing only wheat starch and wheat gluten), gluten dough (lack of starch), and in gliadins and glutenins. The samples were studied in the hydrated state, in the form of powder, film or in solution. Analysis of the studies presented in this review indicates that an adequate amount of water is a critical factor affecting gluten structure.

Influence of wheat flour substitution with potato pulp on dough rheology, microstructure and noodle quality

SummaryThe effects of potato pulp (0–40%) on dough rheology and microstructures, as well as noodle quality, were investigated in this study. Substitution of wheat flour with potato pulp led to a decrease in β‐sheet content, an increase in α‐helix and unordered content for protein in dough, as well as a drop of the storage and loss modulus, which was mainly caused by the weakening of dough gluten strength. Scanning electron microscopy confirmed that the gluten–starch network could no longer to be observed for the formulated dough containing 30–40% potato pulp. Structural damage of dough induced the increases in optimal cooking time, cooking loss and adhesiveness, and a decrease in cohesiveness of cooked noodles. However, the samples with 20% potato pulp addition showed higher values in water absorption, hardness, springiness and chewiness, indicating that noodles with potato pulp content below 20% were acceptable.

Comparative study of rheology and steamed bread quality of wheat dough and gluten: Starch doughs

To explore the interaction between wheat starch and gluten, the thermomechanical, rheological properties, steamed bread quality of wheat flour, and gluten–starch doughs from different varieties were compared. Thermomechanical analysis showed that the stable time and gelatinization viscosity of model dough were higher than that of wheat dough. The results showed that R model dough (the ratio of starch/gluten is consistent with the original flour) had a higher stable time, strength, viscosity, stability, and extension properties than that of C model dough (the protein content is consistent with the original flour). Steamed bread prepared by model doughs exhibited higher hardness, gumminess, and chewiness. The internal structure of R dough steamed bread exhibited more tightly than that of C model dough steamed bread. Optimization of the starch/gluten ratios in wheat flour will be important for wheat breeding and controlling wheat processing aiming to better control the quality of steamed bread. Practical applications Wheat starch and protein are the two main components of wheat flour. Dough is a complex material with a high degree of elasticity and rheological properties of dough play an important role in end-product quality. The processing of dough is the result of the interaction between starch and gluten, and the interaction affects the rheological properties of dough and ultimately the quality of products. In this study, two models of starch–gluten dough were established. First, starch–gluten ratio of dough was consistent with original wheat flour dough; second, the gluten content was consistent with the original dough. The rheological properties and the quality of steamed bread were compared between the original wheat flour dough and the model dough. The information obtained is expected to be important for wheat breeding and wheat dough processing aiming to broaden the application of wheat and wheat flour.

NaCl mediated physicochemical and structural changes of textured wheat gluten

The study focused on the effect of different concentrations of sodium chloride (0%, 0.5%, 1%, 3%, 5%, and 10%; NaCl) on the physicochemical and structural properties, including texture properties, protein polymerization, rheological properties and morphology formation, of extruded wheat gluten. The hardness, chewiness, and resilience of the extrudates were increased by NaCl. The highest value of the degree of texturization was obtained at 3%, but decreased at 5% and 10%. The extrudates exhibited lower bulk density and darker colour when NaCl was added. The sodium dodecyl sulfate (SDS)-soluble protein polymers exhibited a similar trend and the lowest value was obtained at 3% addition, which indicated the highest degree of aggregation. The addition of NaCl (0.5%–3%) showed positive effect on the oxidation of sulfhydryl groups to disulfide bonds. The content of β-sheets showed an increase tendency at 0.5%–3% NaCl addition. The addition of NaCl increased the storage and loss modulus in wheat gluten dough while decreasing that of the extrudates. Microstructure analysis by light microscopy and SEM confirmed that the fibrous structure was enhanced with increasing levels of NaCl, and the 3% treatment showed the best, but that collapsed at 5% and 10% NaCl concentrations.

Processing conditions and transglutaminase sources to “drive” the wheat gluten dough quality

Gluten proteins are highly impacting the quality of various gluten-based products, and transglutaminases (TGs) are used to influence the protein cross-linking. In this study we monitored the interplay of “harsh” and “mild” gluten processing for dough mixing and pasta-like sheet production and TGs from a commercial and newly sourced bacteria (SB6). Despite the harshly separated gluten presenting strongly cross-linked proteins in the beginning of the mixing, similar levels of polymerization were achieved at the optimum mixing time but with differences in the secondary protein structure. TG addition increased polymerization in wheat doughs, possibly as a result of increased glutenin polymerization, while gliadins become more soluble with SB6. This enzyme also dramatically increased polymerization in mild gluten. These results show that an adequate investigation when using TGs and gluten from various origins is necessary to adequately predict the quality in various gluten-based products, thus, of great relevance to the food industry. Industrial relevanceCurrently, there is a mounting trend towards the modification of gluten proteins to improve technological features and functionality. In breadmaking, when weak flour (low protein content) is used or general stabilization is desired for technological purposes, additives can be used to stabilize the gluten protein matrix. The use of transglutaminase (TG) has grown in popularity as they promote specific cross-linking between residues of glutamine and lysine in proteins. Another way of improving dough functionality is by increasing the oxidation of disulfide groups by adding gluten which is a co-product of the starch industry. Industrial production of gluten includes the use of heating and shear forces, which may impact gluten dough-forming ability. Thus, increased understanding of the interplay of gluten processing and the impact of choice of the TG origin in gluten dough quality is highly applicable in food industry.

Advances in present‐day frozen dough technology and its improver and novel biotech ingredients development trends—A review

AbstractBackground and objectivesIn response to the need for product flexibility and fast response to consumer trends, research interest frozen dough technology has continued to increase since its inception in 1970s. Common categories of these products are prefermented, unfermented, and par‐baked frozen dough products, with widely known frozen dough products such as refrigerated cookies and brownies, sweet rolls, biscuits, dinner rolls, and pizza, sold “as if freshly baked” to the consumer. The underlying catalyst for the development and growth of the frozen dough products in the 1970s–1990s is closely related the development of improver technology and increased research efforts to improve frozen dough quality, thus a steady market growth in frozen dough products in the following. Despite increased popularity of frozen dough products, they are still faced with processing challenges such as reduced yeast activity and viability, damaged dough gluten–starch network, and alteration of individual dough components which are induced by freezing and frozen storage treatment. Therefore, increased research efforts by both industry and academic institutions have been vital in understanding and improving processing parameters as well as the end‐product quality of frozen bread‐dough products. This review provides an overview of the effect of ice crystal characteristics on water redistribution and major components (starch and gluten) and ingredient (yeast) during freezing and frozen storage of frozen bread‐dough systems. Additionally, advances in frozen dough improver technology such as use of hydrocolloids, ice structuring proteins, ice‐nucleating agents, and novel fermentation end products and enzymes that alter ice crystal characteristics to improve steamed bread frozen dough quality are suggested and discussed. In addition, due to the recent increase in popularity of frozen steamed products, they are used as a case study and some critical conditions for their processing were suggested.FindingsFreezing and frozen treatment on key components. Gluten: Gluten protein quality is mainly indicated by gluten macropolymer depolymerization during freezing and frozen storage. In frozen steamed dough systems, SH groups, an indicator of S‐S bond disruption, increased in gluten but fluctuated in glutenin fraction during frozen storage. This invariably increases the molecular weight distribution of the glutenin subunits (HMW‐GS and LMW‐GS). Starch: Freezing and frozen storage induces granule structure re‐organization; decline in amorphous state coupled with increase in crystallinity as starch granule materials leach out influences the A‐ and B‐type granules differently. Yeast: Freezing and frozen storage treatment decreases yeast activity and viability in frozen dough systems; with the degree of damage related to the freezing conditions used (e.g., freezing rates, ice crystal size and location, and ice recrystallization) and ability to metabolize different molecules (e.g., glycerol, trehalose, proline, arginine). Despite loss in activity and viability, yeasts are comparatively advantageous to use than chemical leaveners in frozen steamed dough systems. The degree of damage can be related to the freezing conditions used and ability to metabolize different molecules. Hydrated frozen steamed dough: three water sources identified as rigid, confined, and bulk water are found in the dough matrix system and are redistributed differently through ice crystallization and recrystallization in dough, thus affecting component structure and functionality. Bulk followed by confined water crystallizes to ice during freezing. The freezing rate applied will also affect the ice characteristics, thus altering structure and functionality. Hence, studies on water redistribution induced by ice crystallization and recrystallization may give a deeper understanding in the search of solutions to preserve gluten in frozen dough. Improver and cryoprotective technology: Advances in additives improver technology such as the use of hydrocolloids, ice structuring proteins or antifreeze proteins, and ice‐nucleating agents and the use of novel biotech ingredients and enzyme technology were able to (a) increase yeast cell freeze tolerance and (b) enhance gluten and starch functional (rheological, thermal) properties during freezing and frozen storage treatment. Subsequently, the yeast cells in frozen dough have better fermentative capacity, resulting in improved end‐product quality in terms of higher specific volume, lower hardness, and increased shelf life.ConclusionsThis is attributed to the additives ability to alter ice crystallization and recrystallization characteristics in frozen dough. Knowledge on development of ice crystallization and recrystallization during freezing and frozen storage, respectively, is useful to enable optimization of freezing conditions and reduction in temperature fluctuations to maintain yeast viability and frozen dough quality.Significance and noveltyThis overview adds new knowledge and useful insights into (a) use of biotech ingredients for clean label technology in frozen dough and food industry, a consumer demand trend for clean label products, and (b) optimization of frozen dough processing and equipment technology for modern baking and food industry.

Effects of different high hydrostatic pressure-treated potato starch on the processing performance of dough-like model systems

In this study, potato starch (PS) was processed by high hydrostatic pressure (HHP) at 200, 350 and 500 MPa for 30 min at 25 °C. Effects of HHP-treated PS on the processing performance of PS–gluten and PS–hydroxypropylmethylcellulose (HPMC) dough-like model systems were investigated. For PS–gluten doughs, as HHP pressure increasing, total gas production (from 85 to 204 mL), elasticity (from 43.73 to 59.95%) and relaxation time of loosely bond water (from 20.73 to 25.53 ms) increased significantly (P < .05), while retrogradation rate (from 2.65 to 1.15 Nm) decreased, indicating that HHP-treated PS delayed dough retrogradation and increased active yeast metabolism, recovery capacity and water mobility. For PS–HPMC doughs, in addition to the decreased retrogradation rate and increased total gas production and relaxation time of loosely bond water, the retention coefficient (from 89.9 to 95.4%) and amplitude of tightly bond water (from 15.95 to 20.71%) increased, indicating that HHP-treated PS increased gas holding capacity and tightly bond water content of the dough. In conclusion, HHP-treated PS improved the processing performance of PS–gluten and PS–HPMC doughs.

Effects of Starch From Five Different Botanical Sources on the Fermentation and Gelatinization Properties of Starch–Gluten Model Doughs

Wheat, corn, tapioca, sweet potato, and potato starches are independently mixed into starch–gluten model doughs containing 15% (w/w) vital gluten. Fermentation properties, including gas production, and retention capacities, are studied by recording dough height and gas release kinetics through rheofermentometer. Gelatinization properties are investigated by recording changes of heat transition and dynamic moduli with temperature using a differential scanning calorimeter and control stress rheometer, respectively. Wheat starch (WS)–gluten dough has the greatest total gas production (500 mL) and gas retention coefficient (87.6%), lowest viscosity, and highest dough structure hardening during gelatinization, while potato starch–gluten dough has the smallest total gas production (85 mL) and gas retention coefficient (82.1%), highest viscosity, and lowest structure hardening during gelatinization. In addition, the ultrastructure and freezable and non‐freezable water contents are determined to investigate the structural properties of the starch–gluten model doughs. WS–gluten dough shows the most consistent and uniform ultrastructure, and highest non‐freezable water content (42.60%) among all the starch–gluten model doughs. This suggests that WS–gluten dough exhibits a better processing performance compares to the other four starch–gluten model doughs.

Impact of gluten separation process and transglutaminase source on gluten based dough properties

This study evaluated the effect of the wheat gluten (WG) separation process and transglutaminase (TG) microbial source on WG dough quality, and opportunities to use these factors to tailor dough quality. Two types of gluten (harshly and mildly separated), two types of TG (commercial and novel SB6), and three TG concentrations were evaluated for effects on dough mixing properties, protein structure and solubility. Mildly separated gluten improved dough development parameters, resulting into higher values of most compared with harshly separated gluten. Despite more strongly cross-linked proteins being found in the harshly separated gluten, both gluten types showed similar levels of cross-linking at optimum mixing time, although differences in the secondary protein structure were indicated. Thus, disulfide-sulfhydryl exchange reactions were found to be promoted by mixing, although restrictions on establishment of new bonds because of prior cross-links in the material were clearly indicated. Degree of polymerization in doughs made from mildly separated gluten increased to varying extents with TG addition depending on TG source and concentration. Thus, for the first time, we show that an appropriate combination of WG separation procedure and TG source can be used to tailor gluten dough end-use properties.

Characteristics of the chemical processes induced by celluloses in the model and gluten dough studied with application of FTIR spectroscopy

Abstract Fourier transform infrared spectroscopy (FT-IR) was used to study dehydration of the gluten network caused by supplementation of the model and gluten dough by celluloses differing in particle size and chemical structure. Wheat gluten and model flour reconstituted from wheat starch and wheat gluten was mixed with microcrystalline cellulose, Avicel microcrystalline cellulose PH 101 and PH 302, cellulose (20 μm) and 2-hydroxyethylcellulose in five concentrations: 3%, 6%, 9%, 12% and 18%. Analysis of the gluten dough – cellulose spectra shows bands connected with hydrated β-sheets (1594 cm−1) and microvoids (3422 cm−1) which indicate adequate hydration of the gluten network in the gluten dough. Contrary to gluten dough – cellulose, difference spectra of model dough – cellulose shows signs of gluten dehydration e.g. H-bonding in β-turns (1659 and 1665 cm−1) and antiparallel-β-sheets (1683 cm−1). Presence of the bands at ca. 1221 and 1313 cm−1 indicate incorporation of the celluloses into gluten network in the gluten and model doughs. Both phenomenon, incorporation of the celluloses accompanied by a decrease in their crystallinity as well as two-fold reduction of the water addition during preparation of supplemented doughs may contribute to the dehydration of gluten network.

Effects of enzymes to improve sensory quality of frozen dough bread and analysis on its mechanism.

Baking quality of frozen dough is negatively affected by dough weakening and by a reduction in both yeast viability and activity during freezing and frozen storage. The objective of this study was to investigate effects of different enzymes, such as α-amylase, xylanase, celluase, glucose oxidase, and lipase on the texture and sensory quality of bread after frozen storage, as well as on dough properties, in terms of fermentation characteristics, freezable water contents and microstructure. Except for α-amylase, other enzymes improved the bread sensory quality and got higher overall acceptability, especially xylanase. Dough fermentative behavior showed that the maximum heights of frozen dough were increased by 33.2, 19.7 and 7.4%, respectively with xylanase, cellulase and lipase. Cellulase lowered gas holding ability of dough. Thermodynamic properties indicated that addition of enzyme decreased the freezable water contents in frozen dough. Scanning electronic microscopy revealed that freezing and frozen storage disrupted dough gluten network causing separation of starch granules from the gluten matrix. Inclusion of cellulase, xylanase and lipase made the frozen dough having a more continuous gluten network and smoother surface, and glucose oxidase increased the stability of the gluten work.

Effects of starch from five different botanical sources on the rheological and structural properties of starch–gluten model doughs

Wheat, corn, tapioca, sweet potato and potato starches were independently mixed into starch–gluten model doughs containing 15% (w/w) vital gluten. Rheological properties, including linear viscoelasticity region, frequency dependence and recovery capacity, were studied by strain sweep, frequency sweep, and creep and recovery measurements. Structural properties were also investigated by measuring the disulfide bonds (–SS–) content, SDS-PAGE and low-resolution 1H nuclear magnetic resonance. Wheat starch (WS)–gluten dough had the greatest linear viscoelasticity region (0.190%), lowest frequency dependence (0.128) and greatest recovery capacity (67.39%), while potato starch–gluten dough had the smallest linear viscoelasticity region (0.126%), greatest frequency dependence (0.195) and lowest recovery capacity (54.97%). Furthermore, WS–gluten dough showed the highest disulfide bonds (–SS–) content (3.47μmol/g), lowest intensity of extracted glutenin bands and highest bond water content (23.20%). This suggested that WS–gluten dough formed stronger starch–gluten interactions compared with those of the other four starch–gluten model doughs.

Olive leaves extract encapsulated by spray-drying in vacuum fried starch–gluten doughs

Olive leaves extract (OLE) was microencapsulated with inulin (OLE-IN) by spray-drying using a central composite design. Oleuropein encapsulation efficiency and recovery values were over 87% in the OLE-IN microparticles obtained under optimal conditions. OLE or OLE microparticles were added into starch–gluten fried matrices with the aim of studying the effect of microencapsulation and the frying method on the polyphenols content and antioxidant activity, fat content and crispness. Vacuum starch–gluten fried samples absorbed slightly, but significantly, less oil than the atmospheric fried ones (except for the dough with 350mg GAE/kg), but crispness was higher in the atmospheric fried products. Although vacuum fried matrices showed significantly higher content of polyphenols than atmospheric fried matrices, both types of matrices showed similar antioxidant activity, suggesting the formation of antioxidant metabolites derived from the Maillard reaction during the atmospheric frying. The results highlighted the importance of the microencapsulation of OLE to preserve the beneficial effects of polyphenols in processed food.

Impact of Characteristics of Different Wheat Flours on the Quality of Frozen Cooked Noodles

In this study, the impact of characteristics (physicochemical, rheological, and pasting properties) of different wheat flours on the quality of frozen cooked noodles was investigated. In this sample set, results showed the cooking loss of noodles related negatively to flour swelling power. The water absorption of noodles related negatively to the dough stability time, the area, and the resistance to extension. The wheat flour with higher dough development time resulted in frozen cooked noodles with higher hardness, chewiness, and adhesiveness. Springiness of noodles correlated negatively to degree of softening. The tensile properties of frozen cooked noodles were influenced by rheological and pasting properties of wheat flours. The present study indicated high quality of frozen cooked noodles demanded wheat flours with high dough gluten strength, peak viscosity, and final viscosity and with low pasting temperature.

Effect of Barley β-Glucan on the Gluten Polymerization Process in Dough during Heat Treatment.

Barley (Hordeum vulgare L.) β-glucan (BBG) is of interest as a result of its health benefits, but BBG presents significant disruptions on the gluten network, with a negative impact on food texture. To clarify the interaction between BBG and gluten in dough, the dynamic rheological, thermochemical process of gluten and microstructure of dough with BBG during heating were detected. The results showed that BBG delayed the gluten thermopolymerization reaction during heating and affected polymerization of specific molecular weight protein subunits. These impacts depended upon the heating temperature and time. When heating under 25-65 °C, tan δ of the dough reached the highest level at the BBG concentration of 1%. However, under the temperature of 65-95 °C, tan δ was positively correlated with the BBG content (0-3%). The differential scanning calorimetry curves revealed that the peak temperature (TP) of the two endothermic peaks increased by 3.86 and 3.10 °C. Size-exclusion high-performance liquid chromatography analysis showed that BBG mainly affected the peak area of gliadin and glutenin. Furthermore, after 3% BBG was added, the bands of 59.8 and 64.9 kDa in sodium dodecyl sulfate-polyacrylamide gel electrophoresis patterns delayed, vanishing for 120 s when heating at 95 °C. Therefore, BBG delayed the polymerization reaction of specific molecular weight protein subunits rather than all of the proteins.