Gluten Network Research Articles

Noncovalent Conjugates of Anthocyanins to Wheat Gluten: Unraveling Their Microstructure and Physicochemical Properties.

Intake of polyphenol-modified wheat products has the potential to reduce the incidence of chronic diseases. In order to determine the modification effect of polyphenols on wheat gluten protein, the effects of grape skin anthocyanin extract (GSAE, additional amounts of 0.1%, 0.2%, 0.3%, 0.4%, and 0.5%, respectively) on the microstructure and physicochemical properties of gluten protein were investigated. The introduction of GSAE improves the maintenance of the gluten network and increases viscoelasticity, as evidenced by rheological and creep recovery tests. The tensile properties of gluten protein were at their peak when the GSAE level was 0.3%. The addition of 0.5% GSAE may raise the denaturation temperature of gluten protein by 6.48 °C-9.02 °C at different heating temperatures, considerably improving its thermal stability. Furthermore, GSAE enhanced the intermolecular hydrogen bond of gluten protein and promoted the conversion of free sulfhydryl groups to disulfide bonds. Meanwhile, the GSAE treatment may also lead to protein aggregation, and the average pore size of gluten samples decreased significantly and the structure became denser, indicating that GSAE improved the stability of the gluten spatial network. The positive effects of GSAE on gluten protein properties suggest the potential of GSAE as a quality enhancer for wheat products.

Effect of high-molecular-weight glutenin subunits silencing on dough aggregation characteristics

The qualities of wheat dough are influenced by the high-molecular-weight glutenin subunits (HMW-GS), a critical component of wheat gluten protein. However, it is still unknown how HMW-GS silencing affects the aggregation characteristics of dough. Two groups of near-isogenic wheat were used to study the effects of HMW-GS silencing on dough aggregation characteristics, dough texture characteristics, and dough microstructure. It was observed that the content of gliadin in LH-11 strain significantly increased compared to the wild-type (WT). Additionally, the amount of glutenin macropolymer and the glutenin/gliadin both decreased. The aggregation characteristics and rheological characteristics of the dough in LH-11 strain were significantly reduced, and the content of β-sheet in the dough was significantly reduced. The HMW-GS silencing resulted in a reduction in the aggregation of the gluten network in the dough, which related to the alteration of the secondary and microstructure of the gluten.

Solvent retention capacity as a useful tool for quality evaluation of flours produced from Slovak bred wheat varieties

Abstract Wheat varieties (IS Danubius and MS Luneta) bred in Slovakia were assessed for their bakery potential. It was found that flour produced from IS Danubius was characterised by significantly higher level of wet and dry gluten content (30.91 and 20.53 %, respectively) and exhibited higher gluten swelling capacity (29.3 %) in comparison to commercial wheat flour that is usually available in Slovak markets. Solvent retention capacity (solvation in specific solvents) of the tested flours was also determined. The measurements showed that these parameters significantly differ from those determined for commercially available flour, whereas the flour produced from IS Danubius wheat variety had the highest lactic acid retention capacity (124.15 %). Correlation analysis indicated strong positive correlations between solvent retention capacity values and gluten characteristics. Furthermore, it was found that baked rolls prepared from IS Danubius flour showed significantly higher loaf volume compared to commercial wheat flour. This study proves lactic acid retention capacity and sucrose retention capacity as parameters enabling the prediction of gluten network quality in dough and of qualitative parameters of baked goods. From the sensory evaluation resulted that the highest score for overall acceptance was observed in IS Danubius baked rolls, which significantly differs from both MS Luneta and commercial wheat flour.

The Application and Potential of Oleogels in the Food Industry

This article explores the utilization and potential of oleogels in various food applications, with a specific focus on their incorporation in bread making, meat products, dairy products, and their role in delivering fat-soluble nutrients. In the context of bread production, oleogels successfully alter the properties of the gluten network without impairing its formation, prolonging bread's shelf life and lowering its saturated fatty acid (SFA) content. However, further research is still needed, especially concerning potential changes in texture and flavor. The integration of oleogels in dairy products holds the potential for reformulation to decrease saturated fatty acid content while maintaining the desired texture and nutritional value. Additionally, oleogels are anticipated to revolutionize the delivery of fat-soluble nutrients by enhancing their bioavailability through added protective capabilities. Nevertheless, the full commercialization of oleogels has yet to be realized due to potential alterations in texture, mouthfeel, and flavor, which may impact consumer acceptance. Despite these obstacles, oleogels are widely used, have the ability to lower SFA in food items, and have the capacity to offer critical nutrients. This suggests that integrating oleogels into a variety of food applications is very practical. Continued research is essential to unlock the full potential of oleogels and drive a new era of health-conscious food production.

Potential of microbial and cereal β-glucans as hydrocolloids in gluten-free oat baking

To compensate the absence of viscoelastic gluten network, water-binding and viscosity-forming ingredients, hydrocolloids, are commonly used in gluten-free doughs. Currently, hydrocolloids are often E coded while many consumers prefer “clean-label” alternatives. For instance, microbial and cereal β-glucans are known to produce viscosity. In this study, the technological potential of these β-glucans as natural hydrocolloids was evaluated in gluten-free oat baking. Microbial β-glucan was produced by fermentation with P. claussenii using oat bran concentrate (OBC) as a raw material. Oat β-glucan was studied as various forms of OBC: as untreated OBC, pre-treated OBC suspension, and water-extractable fraction of OBC suspension (oat β-glucan extract). The baking properties after natural hydrocolloid additions were compared to a reference oat bread which was baked with common commercial hydrocolloids (psyllium, HPMC). The levels of hydrocolloids in the doughs were optimised by a test baking method. Among the hydrocolloids studied, the best bread properties were achieved with oat β-glucan extract as a hydrocolloid, as the breads resulted in similar specific volume and 37% lower staling rate compared to oat breads baked with commercial hydrocolloids. Thus, oat β-glucan extract provided a feasible and “clean-label” alternative for commercial hydrocolloids in gluten-free oat baking.

WHEAT FLOUR QUALITY CORRECTION BY USING ENZYME PREPARATIONS

Over the past decade, the flour milling industry has been undergoing active development, with the reconstruction of existing enterprises and increased construction of new flour mills under conditions of declining quality of incoming raw materials, high competition and low profitability of bakery enterprises and flour mills. Therefore, such enterprises should be able to produce not only standard flour but also flour with specified quality indicators. One example is flour with enhanced baking properties intended for special product groups such as loaves, baguettes, buns, etc. Standard Ukrainian flour, produced due to its low protein and gluten content, cannot always be used for these products. The aim of the study was to investigate the effect of a protease-acting enzyme preparation on the gluten network of flour and to develop a complex-acting technological additive. To study the quality of flour, both conventional and innovative evaluation methods were used with the help of the Mixolab device, and trial laboratory baking of samples was carried out. To improve the protein-proteinase complex, the enzyme preparation Neutrase 15 BG was used in three dosages: minimum (0.02 g/kg), medium (0.06 g/kg) and maximum (0.1 g/kg). For complex action, a mixture of enzyme preparations Neutrase 15 BG and Fungamyl 2500 SG in the following dosages: 0.02 g/kg + 0.002 g/kg; 0.02 g/kg + 0.005 g/kg; 0.02 g/kg + 0.01 g/kg. The paper analyses the quality of flour produced by Ukrainian producers, determines the effect of a proteolytic enzyme on the quality characteristics of gluten, evaluates the baking properties of graded flour with a proteolytic enzyme, and develops a technological additive to adjust the protein-proteinase complex of flour. The analysis of previous studies has shown that high-grade flour from the Southern region is characterised by low quality, namely a low gluten content of 24.0-25.2% with excessively resistant gluten properties of 47-60 units, and low amylolytic activity – the falling number is above 460-480 s. It has been established that at the minimum and average dosage of Neutrase 15 BG, the specific volume of bread increased by 0.5% and at the maximum – by 0.2%, with a clear deterioration in organoleptic characteristics. Therefore, it makes sense to use this enzyme in low dosages to prevent stickiness of the dough. According to the results of the influence of the technological additive on bread quality indicators, it has been found that in the sample with the following dosage of Neutrase 15 BG and Fungamyl 2500 SG – 0.02 g/kg + 0.01 g/kg, respectively, the volume and porosity of bread increased by 1.3 times and 1.1 times, respectively.

Effect of partial substitution of wheat flour with kiwi starch on dough rheology, microstructure, the quality attributes and shelf life of Chinese steamed bread

Chinese steamed bread (CSB), a conventional high-GI staple food, with a short shelf life and a single flavor. In this work, 10–20 % kiwi starch (KS) was used to substitute wheat flour for the production of CSB and the effects of different substitution ratios on the quality and shelf life of mixed flour, dough, and CSB were explored. The results showed that the substitution of KS could improve the water binding capacity of mixed flour and lead to easier pasting in the system, lower the cooking power consumption, increase and improve the viscoelasticity and gas holding capacity of the dough, and make the microstructure more compact and uniform. As the substitution ratio increased, the reduction in protein content within the system further affected the formation of the gluten network, leading to a significant decrease in the CSB's specific volume and cohesiveness, whereas the chewiness and hardness were significantly improved. Meanwhile, KS substitution significantly reduced the starch hydrolysis rate and estimated glycemic index of CSB. 10 % KS substitution enriched the aroma and color of CSB, improved its internal organizational structure, and became more popular among consumers. A substitution ratio of 15–20 % was beneficial for extending the shelf life of CSB.

Insights into the mechanisms underlying ethanol-induced changes in the dough mechanical properties and quality characteristics of fresh noodles

This study investigated the effects of ethanol (0 %∼6%) on the dough mechanical properties and quality characteristics of fresh noodles and elucidated the relationship between the above changes and physicochemical, structural, and molecular properties of gluten. Ethanol reduced the water absorption (from 59.00 % to 52.33 %), stability time (from 8.17 min to 3.33 min) and viscoelasticity of dough, and increased the development time, weakening degree and compliance. Ethanol also decreased the fracture stress of dough sheet, and increased fracture elongation and adhesiveness (from 46.15 g·s to 75.88 g·s). Ethanol decreased the noodles’ hardness (from 5347.41 g to 4442.34 g), break force, tensile distance, and water absorption, while cooking loss was increased. SEM and CLSM showed that ethanol destroyed the compactness of internal structure and inhibited the formation of gluten network in noodles. According to the results of SE-HPLC and RP-HPLC, ethanol dissolved part of the gliadin and inhibited the polymerization of protein.

Enhancing the highland barley-wheat dough network structure and bread quality using freeze-dried sourdough powder with inulin as a protectant

In this study, freeze-dried highland barley sourdough powder containing inulin (SPN) was prepared, and its stability during storage, as well as the effects of SPN on dough network structure and bread quality, were investigated. Results showed that SPN retained a higher number of viable lactic acid bacteria and acid-producing ability in comparison to sourdough powder without inulin when stored at 4 °C for 60 d. The use of SPN was advantageous in the formation of gluten network structure in the dough. Bread prepared with SPN (B2) exhibited a larger specific volume and a softer texture than the highland barley-wheat (1:8, w/w) bread prepared without sourdough (B0) (P < 0.05) and the one prepared with fresh highland barley sourdough (B1) (P > 0.05). Sourdough usage decreased in vitro starch digestibility, yet increased protein digestibility and antioxidant activity, with no significant differences between B1 and B2. Ultimately, B2 showed the highest overall acceptability. The positive effects of SPN may provide insights into future innovations in this area.

Effect of high-temperature drying at different moisture levels on texture of dried noodles: Insights into gluten aggregation and pore distribution

In this study, the impacts of high-temperature drying (80 °C) at varying moisture levels HT1 (30%) and HT2 (12%) on texture of dried noodles were investigated by considering the protein aggregation and pore distribution in both dried and cooked noodles. In comparison to medium-temperature drying (45 °C), an increase in protein aggregation was observed in dried noodles obtained under HT1. Additionally, HT1 conditions led to uneven gluten network and significant variations in pore size, which ultimately reduced the bending resistance of dried noodles from 9.45% to 31.82%. Upon cooking, the protein in noodles from HT1 underwent slight depolymerization, resulting in lower protein aggregation as compared to noodles from HT2, which negatively affected the edible quality of products from HT1. Our findings demonstrated that dried noodle qualities under HT2 increased up to 32.73% compared to medium-temperature drying and HT1, due to suitable protein aggregation and smaller pore distribution associated with HT2. Finally, the degree of protein aggregation in cooked noodles is a more accurate quality indicator than analyzing dried noodles.

Comparative study on nutritional and technological properties of two varieties of black wheat flour and their noodle-making potential.

Comparative studies were conducted on physicochemical and technological properties of two black wheat (BW) varieties (cultivated in Shanxi Agricultural University) and their noodle-making potential. Whole-grain BW noodles showed acceptable cooking loss (≤10%) and strong antioxidant capacity. However, their textural quality remains to be enhanced. Regarding refined flour (RF) of the two BW varieties, Yunhei 14207 showed more anthocyanins, brighter color, and greater thermal stability (as reflected by the higher pasting temperature). 16W16 resulted in greater gluten content and better gluten quality of flour and higher dough stability, which contributed to the lower cooking loss and stronger tensile property of noodles. RF noodles of Yunhei 14207 displayed brighter appearance, although they had weaker tensile property. The stronger gluten network in noodles of 16W16 protected phenolics from release and degradation during drying, cooking, and steaming. Despite phenolics loss, RF noodles of Yunhei 14207 showed antioxidant capacity up to 14.97mg TE/100g. This research would promote understanding of characteristics of BW varieties. Considering the stronger gluten network of 16W16, its fortification in common wheat noodles at high proportion (>50%) may be promising to develop antioxidant noodles with further improved sensory quality.

The Role of Gluten in Food Products and Dietary Restriction: Exploring the Potential for Restoring Immune Tolerance.

Wheat is extensively utilized in various processed foods due to unique proteins forming from the gluten network. The gluten network in food undergoes morphological and molecular structural changes during food processing, affecting the final quality and digestibility of the food. The present review introduces the formation of the gluten network and the role of gluten in the key steps of the production of several typical food products such as bread, pasta, and beer. Also, it summarizes the factors that affect the digestibility of gluten, considering that different processing conditions probably affect its structure and properties, contributing to an in-depth understanding of the digestion of gluten by the human body under various circumstances. Nevertheless, consumption of gluten protein may lead to the development of celiac disease (CD). The best way is theoretically proposed to prevent and treat CD by the inducement of oral tolerance, an immune non-response system formed by the interaction of oral food antigens with the intestinal immune system. This review proposes the restoration of oral tolerance in CD patients through adjunctive dietary therapy via gluten-encapsulated/modified dietary polyphenols. It will reduce the dietary restriction of gluten and help patients achieve a comprehensive dietary intake by better understanding the interactions between gluten and food-derived active products like polyphenols.

The influence of carboxymethyl cellulose and hydroxypropyl methylcellulose on physicochemical, texture, and sensory characteristics of gluten-free pancake.

In this study, gluten-free pancakes were prepared using rice flour and potato starch at a ratio of 50:50. Due to a lack of gluten networks in these ingredients, the hydrocolloid gums including carboxymethyl cellulose (CMC) at 0.5%, 1%, and 1.5% and hydroxypropyl methylcellulose (HPMC) at 1%, 2%, and 3% were added to improve the quality of the final products. The effects of these hydrocolloid gums on the physicochemical, textural, and sensory properties of the gluten-free pancakes were evaluated. Pancakes prepared with wheat flour were used as a control sample. The results showed that the addition of both gums decreased the hardness and chewiness of the gluten-free pancakes while increasing the springiness and their moisture content. Increasing the concentration of the gums resulted in an L* value (lightness) reduction, which produced a darker crust on the pancakes. Moreover, the gluten-free pancakes containing CMC and HPMC had higher specific volumes than the gluten-free samples made without CMC and HPMC. From a sensory point of view, the samples containing 2%, 3% HPMC and 1% CMC received the highest overall acceptance score. Thus, CMC and HPMC can be used as improvers in gluten-free pancakes.

Regulation of baking quality and starch digestibility in whole wheat bread based on β-glucans and protein addition strategy: Significance of protein-starch-water interaction in dough

Whole wheat bread has high nutritional value but is characterized by inferior quality and a high glycemic index. Studies have shown that adding β-glucans and protein can improve bread quality. This study investigated the effects of added oat β-glucan, barley β-glucan, or yeast β-glucan on protein synergy and whole wheat dough and bread quality. The mixing properties, rheological properties, and scanning electron microscopy observations showed that the addition of β-glucan promoted the formation of gluten networks, while the synergy between the wheat proteins and β-glucan resulted in a more robust and stable gluten network and a stronger physical starch envelope. Rapid visco-analysis and thermal property evaluations showed that β-glucan addition inhibited the thermal degradation, gelatinization, and retrogradation of starch. Based on the bread quality results, it was found the β-glucan could cause some damage to the bread baking quality. For example, the hardness of samples with oats, barley, and yeast increased to 881.69 g, 952.97 g, and 631.75 g, respectively, compared to samples without β-glucan (317.49 g), whereas the inclusion of yeast β-glucan proved to be less detrimental. Protein and β-glucan both reduced starch digestion to some degree, and showed better synergistic effects, with the lowest estimated glycemic index of 70.08 observed in bread containing added yeast β-glucan and protein. Therefore, yeast β-glucan and protein mixtures could be selected as viable formulations for enhancing the quality of whole wheat bread.

Influence of magnetic field on gluten aggregation behavior and quality characteristics of dough enriched with potato pulp

This study investigated the effect of varying magnetic field intensities (ranging from 0 to 10 mT) on the quality characteristics of dough with 40 % potato pulp substitution (DPP). The results indicated that the DPP fermented with a 4 mT magnetic field exhibited a significant enhancement in the combination of water and substrate, thereby elevating the viscoelastic properties of DPP through reinforcing the stability of gluten network. Meanwhile, DPP treated with a 4 mT magnetic field exhibited the highest amount of disulfide bonds (11.64 μmol SS/g sample). This is accompanied by a prominent cross-linkage structure, as evidenced by SDS-PAGE and CLSM. Notably, the application of a magnetic field substantially augments the dough's capacity to retain gas during fermentation. In addition, the application of magnetic field significantly increased the wet gluten content (20.85 %, P < 0.05) in DPP, which improved tensile properties and an acceptable color profile. The introduction of a magnetic field induces gluten aggregation, which in turn results in heightened particle size distribution and ζ-potential values. In conclusion, this study emphasize the potential of magnetic field technology as a viable method to enhance the overall quality attributes of dough enriched with potato pulp substitution.

The Interactions of Soy Protein and Wheat Gluten for the Development of Meat-like Fibrous Structure.

Consumers who are environmentally and health conscious are increasingly looking for plant-based alternatives to replace animal-based products in their daily diets. Among these alternatives, there is a growing demand for meat analogues that closely resemble the taste and texture of meat. As a result, significant efforts have been dedicated to developing meat analogues with a desirable meat-like structure. Currently, soy protein and wheat gluten are the main ingredients used for producing these meat analogues due to their availability and unique functionalities. This study observed that high moisture extrusion at moisture levels of 50-80% has become a common approach for creating fibrous structures, with soy protein and wheat gluten being considered incompatible proteins. After the structuring process, they form two-phase filled gels, with wheat gluten acting as the continuous phase and soy protein serving as a filler material. Moreover, the formation of soy protein and wheat gluten networks relies on a combination of covalent and non-covalent interaction bonds, including hydrogen bonds that stabilize the protein networks, hydrophobic interactions governing protein chain associations during thermo-mechanical processes, and disulfide bonds that potentially contribute to fibrous structure formation. This review provides case studies and examples that demonstrate how specific processing conditions can improve the overall structure, aiming to serve as a valuable reference for further research and the advancement of fibrous structures.

Effects of water content and resting on rheology and the gluten network formation of Chinese traditional handmade hollow dried noodle dough

Chinese traditional handmade hollow dried noodle (HHDN) is a popular wheat-based food among the Chinese people due to its easy cooking qualities and smooth texture, which are significantly correlated with the rheological characteristics of HHDN dough. The effects of water content (55, 60, and 65%) and resting time (0, 30, 60, 90, and 120 min) on the rheology and gluten network formation of the HHDN dough were investigated. The modulus during stress relaxation reduced from 8.62 Pa to 2.30 Pa as the water content increased from 55% to 65%. With resting time increased from 0 min to 120 min, the extensibility of the 60% water content dough increased from 64.33 mm to 152.67 mm. With the water content decreased and resting time increased, the glutenin macropolymer (GMP) content increased and the free sulfhydryl content decreased. The microstructure study of the dough showed that extending the resting time was beneficial to the formation of the gluten network. The covalent interactions promote the formation of the gluten network and change the rheological properties of the dough. The dough with 60% water content and 60 min resting would result in the desired quality of the dough, ultimately improving the quality of the noodles.

Debranning of wheat: Quality of flour and thermomechanical, microstructural, and extensional properties of dough

This study investigated the impact of debranning degrees (0, 3, 6, 9 and 12% by weight) on the qualities of wheat flour and dough. The physicochemical and pasting properties of wheat flour and thermomechanical, microstructural, extensional and rheological properties of wheat dough with different debranning degrees were assessed. The insoluble dietary fiber, soluble dietary fiber, protein, and ash contents for debranned wheat flour were significantly higher than that of refined flour. The content of protein was the highest when the debranning degree of wheat was 6%. Debranning degree of 6% significantly increased the gluten index for wheat flour and showed better pasting and mixing properties than untreated samples. Debranning treatment increased the L* value and decreased the a* and b* values of the wheat flour. Furthermore, when the debranning degree increased, the protein matrixes were more continuous and compact, and the starch granules were better entrapped in the gluten network. Debranning treatment caused significant increases in the dough's resistance to extension, extensibility, extensibility area, and extensibility rate, and a decrease in the dough's viscoelasticity. The debranning degree of 6% could effectively improve the parameters such as mixing properties, microstructure, and extensional properties of wheat dough.

Comparative molecular conformation, interaction, and network characteristics of wheat gluten modulated by sodium chloride and sodium carbonate

SummaryThe objective of the study was to investigate the configurational changes and aggregation mechanism of wheat gluten induced by sodium chloride (NaCl) and sodium carbonate (Na2CO3). The results showed that NaCl shielded surface charges of gluten, developed more hydrogen bonds with tyrosine, and stabilised the secondary structure, while Na2CO3 promoted significant transition of the secondary structure from random coils and β‐turn to β‐sheet. Both NaCl and Na2CO3 quenched tryptophan fluorescence and promoted the aggregation of gluten subunits, where Na2CO3 induced covalent bond formation other than disulphides and facilitated gluten network development. Atomic force microscopy images confirmed different molecular surface features in gluten network. In conclusion, both NaCl and Na2CO3 demonstrated the ability to promote rheology, aggregation, and network formation of gluten but different molecular mechanisms were involved. This work provides valuable insights for the processing of salted and alkaline noodles.

Effect of different enzymes on thermal and structural properties of gluten, gliadin, and glutenin in triticale whole-wheat dough

Three enzymes promoted the development of the gluten network in triticale whole-wheat noodles (TWWN). To further understand the mechanism of gluten enhancement, the effects of three enzymes on the structure of gluten and its fractions (gliadin and glutenin) were evaluated. The results showed that glucose oxidase (GOD), xylanase (XYL), and laccase (LAC) decreased the content of sodium dodecyl sulfate (SDS) extractable proteins. The content of glutenin subunits was reduced by 17.25 %, 30.60 %, and 20.09 % with the addition of GOD, XYL, and LAC, respectively. Furthermore, GOD and LAC increased the content of glutenin macropolymer (GMP) by 2.64 % and 7.71 %, respectively, suggesting the promotion of glutenin aggregation. The addition of three enzymes decreased the weight loss and increased the degradation temperature of the gluten and its fractions. GOD and XYL decreased the fluorescence intensity of gluten and its fractions, except for XYL which increased the fluorescence intensity of glutenin by 10.50 %. Intermolecular interactions and surface hydrophobicity were enhanced by XYL in gluten and its fractions. GOD and LAC decreased the free sulfhydryl content and increased the β-sheet content, suggesting that the covalent interaction between gluten fractions was enhanced. Therefore, this research can enrich the theoretical study of enzymatic cross-linking.