Gluten Network Research Articles

Effect of tea polyphenols on the quality of frozen cooked noodles

AbstractBackground and ObjectivesThe growing consumer demand for natural, healthy, and convenient food options has led to the rising popularity of frozen cooked noodles (FCN). Tea polyphenols (TPs), known for their diverse biological activities, are increasingly being utilized as a natural food additive in research and development. Therefore, this study aims to investigate the effects of TPs on the thermal and pasting properties of wheat flour as well as their influence on the quality of FCN.FindingsThe results from differential scanning calorimeter and RVA analyses showed that TPs did not significantly affect the thermal and pasting properties of wheat flour. However, the addition of low‐dose TPs (<1.5%) improved the quality of FCN during storage. Texture and tensile analyses demonstrated an enhancement in hardness, chewiness, resistance, and an increase in resistant starch content in the noodles. Low‐field nuclear magnetic resonance findings revealed an increase in the proportion of strongly bound water, accompanied by a decrease in free water content. Scanning electron microscopy observations illustrated a well‐developed gluten network structure. In contrast, the incorporation of 1.5% TPs adversely affected the quality of FCN.ConclusionsThe appropriate integration of TPs plays a significant role in alleviating the quality degradation of FCN during storage.Significance and NoveltyThis study provides a theoretical basis for the development of polyphenol‐enriched flour products and functional foods.

Effects of interaction between wheat bran dietary fiber and gluten protein on gluten protein aggregation behavior.

Effects of wheat bran dietary fiber (WBDF) as a nutritional additive on flour products quality mainly depends on the interaction between WBDF and gluten protein. In this study, the effects and mechanisms of WBDF with different particle sizes and additive amounts on gluten protein aggregation behavior were investigated. The results showed that the addition of WBDF led to a decrease in free sulfhydryl content, particle size, molecular weight and gluten macromer (GMP) content, an increase in zeta potential and SDS-extractable protein content, and a deterioration in the gluten network morphology compared to the control group, suggesting that the aggregation behavior of gluten protein was inhibited. When WBDF was added at 3 % and 6 %, dilution effect, mechanical shear, steric hindrance, and non-covalent binding were the main mechanisms leading to depolymerization. Further addition of WBDF (9 %, 12 %) inhibited the depolymerization of gluten protein due to competitive hydration and non-covalent binding. However, when WBDF was added at 15 %, the dilution effect, mechanical shear and steric hindrance of WBDF (88 μm < particle size<150 μm) dominated, and their inhibitory of aggregation induced the formation of a loose gluten network structure. In contrast, the weaker mechanical shear and steric hindrance effects of WBDF (particle size<88 μm) mitigated the degradation of gluten network structures by WBDF.

Isolation of ice structuring proteins from winter wheat in frigid region (Dongnongdongmai1) and the effect on freeze–thaw stability of dough

In this study, ice structuring proteins (WISPs) extracted from winter wheat in a frigid region were prepared and added to frozen-thawed dough. The WISPs were characterized, revealing that they contained a higher proportion of hydrophilic amino acids and had a molecular weight of approximately 15 kDa. The highest thermal hysteresis activity (THA) observed was 0.62 °C. The secondary structure of WISPs was determined to be as follows: β-sheet: 49.33 %, random coil: 13.87 %, α-helix: 16.35 %, β-turn: 20.45 %. The study investigated the effects of different additions of WISPs on the water mobility, glass transition temperature, microstructure, rheological properties, and texture analysis of frozen-thawed dough. The results demonstrated that the inclusion of WISPs reduced the fluidity of water and water migration in the dough during the frozen-thawed cycle. This protective effect preserved the internal structure and gluten network of the dough, leading to increased viscosity, elasticity, and improved texture properties of the frozen-thawed dough. Furthermore, the addition of WISPs at concentrations ranging from 0 % to 0.7 % resulted in a 1.8 °C increase in the glass transition temperature (Tg). Overall, these findings suggest that WISPs can serve as a beneficial additive for enhancing the freeze–thaw stability of dough.

Effects of arabinoxylan extracted from vinegar residue on physicochemical and structural properties of gluten proteins obtained from freeze-thaw wheat dough.

Arabinoxylan is commonly used as a hydrocolloid in frozen dough to improve the texture and the sensory qualities of the products. The effects of vinegar residue arabinoxylan (VRAX) on the secondary structures and microstructures of gluten proteins during freeze-thaw storage were studied, and the underlying mechanism governing these effects was clarified. The results revealed that VRAX improved the textural properties of gluten proteins, but had a negative impact on their viscoelasticity. Additionally, the addition of VRAX increased the number of disulfide bonds and also improved the freezing tolerance of the gluten proteins. It was found that the enthalpy of the gluten proteins decreased by 19.78% following VRAX addition. As a result of the use of VRAX, the freezing procedure resulted in reduced formation of ice crystals, protecting the gluten network structure and preserving the dough's elasticity. The network structure of gluten proteins after VRAX treatment was more ordered and integrated relative to that of frozen blank control gluten proteins. Overall, the freeze-thaw stability of the gluten proteins was enhanced by VRAX. These results suggest that VRAX has potential as an effective cryoprotectant in frozen dough. © 2024 Society of Chemical Industry.

Selection of Wheat Miller's Bran Based on the Sub-aleurone Protein Content Allows Increase of the Quality of Bran-Enriched Bread.

Wheat miller's bran negatively affects the gluten network but contains the grain tissue with the highest gluten content, the sub-aleurone. Here, the aim was to investigate how sub-aleurone gluten proteins in miller's bran affect bran-enriched bread quality. A bread-making experiment was performed with six lab-scale-produced bran samples. These strongly differed in protein content (10.8-18.6%) but had a similar particle size (d50: 1266-1330 μm) and strong water retention capacity (0.71-0.80 mL of H2O/g). Bran protein content variation mainly originated from sub-aleurone protein content variation (10.7-26.2%). Incorporating the bran with the highest versus lowest sub-aleurone protein content increased the loaf volume by 22.4%. 99% of loaf volume variation could be explained by sub-aleurone protein content variation. Conclusively, sub-aleurone protein content is the most important factor regarding bran functionality in bread-making. This was strengthened using commercial bran. Therefore, bran selection based on (sub-aleurone) protein content could be a low-cost, low-effort opportunity for bran-enriched bread-making.

Frozen dough steamed products: Deterioration mechanism, processing technology, and improvement strategies.

Fresh dough products lead to instability in product quality, high production costs, and more production time, which seriously affects the industrial production of the food industry. The frozen dough technology mitigates the problems of short shelf-life and easy deterioration of quality during storage and transportation. It has shown a series of advantages in large-scale industrialization, high-quality standardization, and chain operation. However, the further development of frozen dough is restricted by the deterioration of the main components (gluten, starch, and yeast) caused by freezing. This review summarizes the main production process of frozen steamed bread and buns, and the deterioration reasons for the main component of frozen dough. The improvement mechanisms of raw ingredients, processing technology, processing equipment, and additives on frozen dough quality were analyzed from the perspective of improving gluten network integrity and yeast freeze tolerance. From prefermented frozen raw to steamed products without thawing has become the preferred production process to improve production efficiency. Wheat flour mixed with other flour can maintain the gluten network continuity of frozen dough. The freeze tolerance of yeast was improved by treatment with yeast suspension, yeast cell encapsulation, screening hybridization, and genetic engineering. Process optimization and new technology-assisted fermentation and freezing effectively reduce freezing damage. Various additives improve the freeze resistance of the gluten-starch matrix by promoting protein cross-linking and inhibiting water migration. In addition, ice structural proteins and ice nucleating agents have been proven to change the growth morphology and formation temperature of ice crystals. More new technologies and additive synergies need to be further explored.

Effects of Moisture Migration and Changes in Gluten Network Structure during Hot Air Drying on Quality Characteristics of Instant Dough Sheets.

The impact of hot air drying temperature on instant dough sheets' qualities was investigated based on water migration and gluten network structure changes. The results revealed that the drying process redistributed the hydrogen proton, with deeply bound water accounting for more than 90%. The T2 value decreased as the drying temperature increased, effectively restricting moisture mobility. Meanwhile, microstructural analysis indicated that instant dough sheets presented porous structures, which significantly reduced the rehydration time of instant dough sheets (p < 0.05). In addition, elevated drying temperatures contributed to the cross-linking of proteins, as evidenced by increased GMP and disulfide bond content (reaching a maximum at 80 °C), which improved the texture and cooking properties. Hence, the water mobility was effectively reduced by controlling the drying temperature. The temperature had a facilitating impact on promoting the aggregation of the gluten network structure, which improved the quality of the instant dough sheets.

The influence of non-starch polysaccharides on the formation mechanism of wheat dough

The study examined the effects of oat β-glucan (OβG), chitosan (CTS), araboxylan (AX), and fructosan (FOS) on wheat dough formation. Adding 0–7 % OβG, AX, and FOS increased SS content, enhancing gluten stability. D-AX and D-FOS showed higher β-sheet structures, higher air retention and gluten network, smaller pores and denser structures, higher elastic and viscosity moduli. Excessive OβG and CTS could reduce the dough stability, and β-turn and β-sheet ratios, respectively. Therefore, B-7AX and B-7FOS exhibited lower hardness indices during storage, leading to a smoother appearance and more orderly gas chamber distribution. The study provides a theoretical foundation for using non-starch polysaccharides in flour-based products.

Unveiling the binding mechanism between wheat arabinoxylan and different molecular weights of wheat glutenins during the dough mixing process

Water-soluble arabinoxylans (AX) is an important dietary fiber in wheat bran that influence the gluten network. However, a comprehensive understanding of the mechanism remains unclear. This study compared the interactions between AX and high/low molecular weights of glutenin (HMW/LMW) and found that AX-HMW developed a more uniformed structure than AX-LMW. The optimized property was found at 8% AX (AX8-HMW) when the disulfide bonds, foaming and emulsifying properties reaches highest, which is better than the optimized AX4-LMW. However, higher AX ratio led to poor properties due to AX self-aggregation. The enhancement property can be associated with the formation of molecular complexes. Both HMW and LMW can capture and encapsulate AX to form stable structures, with the binding strength of AX-HMW being stronger than that of AX-LMW, resulting in macroscopic properties. Our findings clarify the interaction mechanism between AX and different molecular weight of glutenins which contributes to understand the role of AX in the dough mixing process.

Arbuscular mycorrhizal fungi affected soft wheat quality properties and nutritional index by regulating the composition and secondary structure of protein

Arbuscular mycorrhizal fungi (AMF) inoculation has important regulatory influence on plant growth and nitrogen uptake, which are intimately associated with soft wheat yield and quality. The study aimed to investigate the impact of AMF inoculation on soft wheat grain yield, protein compositions, protein quality, secondary structure of gluten, dough properties and biscuits baking quality. In this study, AMF inoculation significantly increased grain yield. AMF inoculation decreased grain protein content by 5.1%, glutenin content by 8.5%, GMP by 14.3%, and HMW-GS by 8.8% compared with CK. Conversely, AMF inoculation increased the ratio of gliadin/glutenin. Further analysis showed AMF treatment had a looser gluten network than CK, significantly reduced β-sheet and β-turn content, while α-helix content increased. The nutritional index of grain protein was slightly reduced under AMF inoculation, yet the biological value was improved. Reduced wet gluten content, gluten performance index and dough development time under AMF treatment through regulation of soft wheat protein composition and gluten protein structure. Therefore, biscuits in AMF treatment showed reduced thickness, hardness, significantly greater spread ratio and sensory score compared with CK. These indicate that AMF application would be a beneficial agronomic practice to synergistically optimize yield and grain quality in soft wheat.

The Impact of Ganoderma lucidum (Curtis) P. Karst. Supplementation on the Technological, Chemical, and Quality Parameters of Wheat Bread

This study explores the incorporation of Ganoderma lucidum (Curtis) P. Karst. (Reishi mushroom) into wheat bread to develop a functional food with enhanced nutritional value. Reishi powder was added to bread formulations at levels of 3%, 6%, 9%, and 12% to assess its effects on physicochemical, nutritional, and sensory properties. The 12% Reishi supplementation resulted in a twofold increase in total dietary fibre (from 7.21 g to 17.08 g per 100 g dry matter) and significant (p &lt; 0.05) elevations in mineral content, particularly calcium (68%), iron (32%), and manganese (61.9%). Carbohydrate content decreased markedly by 27%, contributing to a 19.33% reduction in caloric value. Reishi addition improved bread yield and reduced baking losses, enhancing production efficiency. However, higher Reishi levels negatively impacted bread volume, possibly due to interference with gluten network formation. An increase in crumb moisture was observed, contributing to extended freshness. Sensory evaluation revealed that loaves of bread containing up to 6% Reishi were acceptable to consumers, whereas higher levels detrimentally affected flavour and aroma. Therefore, Reishi-enriched bread, particularly with 6% supplementation, presents a promising functional alternative to conventional wheat bread, optimising nutritional benefits while maintaining consumer acceptability.

Response of the distribution and molecular transition of gluten proteins and quality of Chinese steamed bread to different hydration levels

This study systematically explored how different hydration levels (45 %, 50 %, and 55 % water addition) affect the evolution of gluten network morphology, distribution, conformational and molecular transition, and moisture migration during the processing of Chinse steamed bread (CSB), and their impact on quality formation. Higher hydration levels resulted in a more uniform distribution and fibrous structure of the gluten network during mixing. However, excessive hydration (55 %) caused gluten fibers to rupture during fermentation. This increased the specific volume but decreased the chewiness and stickiness of CSB. MRI results highlighted that differences in moisture migration and internal structure among samples with different hydration levels were enlarged after steaming. AFM images revealed the increase in both protein molecular chain height and width with increasing hydration level, particularly after steaming. Moreover, high hydration levels promoted the depolymerization of glutenin macropolymers during mixing, fermentation, as well as repolymerization during cooking. These results indicated that both macroscopic qualities and molecular structure of gluten protein became more sensitive to the physical and biochemical processes during CSB processing. These dynamic transitions play a crucial role in determining dough rheological properties and CSB's overall quality. This research offers theoretical insights for precise dough product regulation and understanding underlying mechanisms.

Comparison of different colored barley hordein/glutelin techno-functional and its ratio modulation on the improvement of reconstituted dough's dynamic thermal processing behavior: A mechanistic investigation

Aiming to boost the high-value utilization of colored barley resources and to broaden its processing depth in cereal products. This study compared the techno-functional characteristics of hordein/glutelin, a key component for gluten in white (W), blue (B), and black (BK) barley, and attempted to modulate their ratios for enhancing reconstituted dough thermal processing suitability. Results indicated that white barley's hordein/glutelin techno-functional profiles are more adapted for dough processing. During dough thermal processing, C2-C3 interval changes were mainly reflected in morphological structure, water distribution, rheological behavior, and textural properties, while the C3-C4 interval variations were interpreted as protein secondary/tertiary structural transitions and intermolecular interactions. Notably, “hordein: glutelin = 50:50″ was a crucial factor in determining the barley dough quality, i.e., low hordein ratio (25:75) was unfavorable for gluten matrix and continuous network formation, whereas its excessive ratio (75:25) weakened the protein aggregation behavior and gluten interaction with starch. Correlation analysis showed that the gluten network's connection density/porosity, protein's secondary structure, and ionic bond strength are key factors modulating dough processing suitability. Therefore, by rationally regulating the hordein/glutelin ratio, barley dough products can be produced with various edible characteristics for consumption. Also, attention should be focused on breeding high hordein ratio barley kernels to improve their gluten profile and thus promote its potential application in cereal processing.

Effect of different gliadin/glutenin on the oil content of fried dough sticks: insights obtained from macroscopic to microscopic scales.

Fried dough sticks, widely enjoyed in southeast Asia, are made by frying a mixture of wheat flour and water at high-temperature. With the move towards industrial production, there is an increasing demand for healthier versions. Understanding the key properties of fried dough sticks and how the ingredients interact is crucial for meeting these health-focused consumer preferences. In this study, the connections between the dough's rheological and thermal properties, alongside the interactions between gluten proteins and the oil content in fried dough sticks, were examined and analyzed at varying gliadin to glutenin mass ratios (Gli/Glu). The results indicated that a general decrease in the viscoelastic properties of the dough was associated with an increase in the Gli/Glu ratio. Furthermore, a heightened concentration of gliadin was observed to augment the mass loss of gluten proteins, thereby engendering a spatially sparse network structure. Additionally, this excessive presence of gliadin precipitated the thermal instability within the dough, necessitating an augmented chemical force to preserve the stability of the gluten network structure. At the Gli/Glu ratio of 5:5, the gluten protein exhibited enhanced thermal stability and minimal mass loss. At this specific ratio, the gluten network was characterized by a comparatively high prevalence of extended gluten films and short-chain structures, which resulted in the production of fried dough sticks possessing minimal structural oil content. The study provided a theoretical basis for identifying the Gli/Glu ratio as an effective approach to modulate the oil content in fried dough sticks. © 2024 Society of Chemical Industry.

Effect of wheat flour particle size on the quality deterioration of quick-frozen dumpling wrappers during freeze-thawed cycles

To reveal the effect of wheat flour particle size on the quality deterioration of quick-frozen dumpling wrappers (QFDW) during freeze-thawed (F/T) cycles, the components and physicochemical properties of wheat flours with five different particle sizes were determined and compared, along with the changes in texture and sensory properties, water status, and microstructure of QFDW during F/T cycles. Results showed that as particle size decreased, the damaged starch content and B-type starch content increased, the water absorption increased, and the gluten strength decreased. Furthermore, F/T cycles negatively impacted the quality of QFDW, evidenced by decreased texture properties and sensory evaluation score, water redistribution, higher freezable water content, and disruption of gluten network. Notably, QFDW made from larger particle size wheat flours required the shortest duration when traversing the maximum ice crystal formation zone. The QFDW made from larger particle size wheat flours formed a more stable starch-gluten matrix, which resisted the damage caused by ice recrystallization, demonstrating better water binding capacity and F/T resistance. The results may provide theoretical guidance for the study of QFDW quality and the moderate processing of wheat flour in actual production.

Identification and mechanism of wheat protein disulfide isomerase-promoted gluten network formation.

Formation of the gluten network depends on glutenin crosslinking via disulfide bonds, and wheat protein disulfide isomerase (wPDI) plays an important role in this process. Here, we identify a substrate gluten protein of wPDI and the mechanism underlying wPDI-promoted glutenin crosslinking. Farinographic, rheologic, and alveographic analysis unambiguously proves that wPDI improves gluten network formation, which is directly observed by 3D reconstruction of the gluten network. Protein analysis and LC-MS/MS reveal that glutenin subunit 1Dx5 is primarily recruited by wPDI to participate in gluten network formation, and its cysteine-containing N-terminal domain (1Dx5-NTD), which harbors three cysteine residues for crosslinking, is purified. 1Dx5-NTD interacts with wPDI in both redox states, possibly folded by reduced wPDI and then catalyzed by oxidized wPDI, as further evidenced by wPDI-promoted self-crosslinking. Consistent with macroscopic observations, our results suggest that wPDI folds 1Dx5-NTD into β-strand structure that favors disulfide bond formation.

Effects of heterotrophic Euglena gracilis powder on dough microstructure, rheological properties, texture, and nutritional composition of steamed bread

This study investigated the effects of incorporating different levels of Euglena gracilis microalgae powder (MP) on the dough properties, rheology, and quality attributes of Chinese steamed bread (CSB) for the first time. Moderate levels of MP (2%) reinforced the gluten network and improved protein structure, while higher levels (4–8%) adversely affected the gluten network and rheological properties. The addition of MP decreased the specific volume, pore number, and pore density of CSB, but increased pore size, hardness, and chewiness. It also imparted a yellow color to the CSB and slowed down moisture loss during storage. Notably, MP effectively increased the protein and lipid content of CSB, enhancing its nutritional value. The results suggest that optimizing the MP level is crucial to achieve nutritional enhancement while maintaining desirable texture and sensory attributes. An addition of 2% MP can strike a balance between nutrition and the overall quality of the final product.

Enhancing freeze-thaw stability of frozen dough with deacetylated konjac glucomannan: The role of degree of deacetylation

The effect of different degrees of deacetylation (DDs) of deacetylated konjac glucomannan (DKGM) on the gluten structure, water state, and yeast activity of frozen dough was evaluated. The moderate DKGM group maintained a more continuous gluten network after three freeze-thaw cycles, as evidenced by an 8.67% increase in disulfide bond content and a 15.01% increase in α-helix content compared to the KGM group. DKGM effectively impeded bound water migration, with the moderate DKGM group retaining 8.28% more bound water than the KGM group after three freeze-thaw cycles. The stabilization of gluten structure and water state in frozen dough by DKGM resulted in higher yeast activity in the low and moderate deacetylation groups (DD = 31.31% and 50.24%). Additionally, DKGM enhanced the quality of frozen steamed bread. The results indicate that DKGM with a moderate DD (50.24%) effectively alleviates the quality deterioration of frozen dough. These findings suggest that DKGM has great potential as a novel cryoprotectant for frozen dough, with DD being a crucial factor in its cryoprotective effect.

Unlocking the potential of rice bran oil body as fat replacement in cookies: single and double crosslinked binary emulsion-filled gels based on lutein-loaded rice bran oil body emulsion.

Rice bran oil body is rich in nutritional value, which is a byproduct of rice processing. The aim of this study is to develop a novel emulsion-filled gel with lutein-loaded rice bran oil body and investigate its functionality as a fat replacer in cookies. The effects of incorporating structured oil body in the form of emulsion-filled gel instead of butter in cookies with a ratio of 0, 10, 20 and 50 wt% formulation were determined by measuring appearance, texture, thermodynamic properties, moisture distribution and microstructure. The results demonstrated the relationship between geometry, moisture and structure. The 20 wt% emulsion-filled gel substitution ratio yielded mobility and distribution abilities of melted fat and sugar in the cookies that were closest to those of butter. The addition of emulsion-filled gel increased the L* value and decreased the a* value, while the b* value of the cookie increased due to the advanced delivery of lutein by oil body. By controlling the addition ratio, the texture of the cookies can be adjusted. Starch granules were separated due to colloidal particles, reducing saturated fat content and decreasing cookie gelatinization enthalpy. The fat coating on starch particles enhanced the binding capacity of free water, improving air entrapment and forming a constrained gluten network structure. These findings provide a theoretical basis for rice bran oil body as a novel substitute for butter in the development of healthy, high-quality cookies. © 2024 Society of Chemical Industry.

Contribution of yeast freezing to the quality of frozen dough: Rheological properties, protein depolymerization, gluten conformation and water state

The present study has comparatively investigated the variation in yeast leachates in frozen suspension and dough systems and assessed the effects of leachate released from frozen yeast cells on dough rheology, protein molecular weight distribution, gluten conformation, and water state. The results revealed that yeast in the dough was more susceptible to freezing than that in the suspension and released more low-molecular-weight metabolites (e.g., trehalose, glutathione, and amino acids) into the dough matrix. Dynamic rheological measurements showed that frozen yeasted dough had weaker viscoelastic properties than non-yeasted dough. Fourier transform infrared spectroscopy revealed a high fraction of β-turns and random coils at the expense of α-helices and β-sheets, demonstrating a flexible protein secondary structure and increase in weakened hydrogen bonds in the gluten network. The presence of yeast in the frozen dough facilitated dough depolymerization via the cleavage of interchain disulfide bonds of gluten protein and softened the gluten network structure. Yeast leachates released from frozen yeast cells caused water redistribution in the dough and increased water release from the weakened gluten network, increasing freezable water content. This study has revealed the essential role of yeast freezing in gluten depolymerization and the deterioration of dough quality.