Influence of gluten and starch granules interactions on dough mixing properties in wheat (Triticum aestivum L.)

Effect of magnetic fields on the structure, properties, baking performance of frozen wheat dough at different frozen stage

As an emerging physical technology, magnetic fields have been used to improve the quality of frozen and refrigerated foods. This study compared the effect of applying a static magnetic field (2 mT) at different stages of freezing and storage on the quality of frozen dough. Results suggested that the magnetic field significantly impacted frozen dough quality. It not only prevented the formation of ice crystals during the pre-freezing stage but also inhibited ice crystal growth during the following frozen storage. This effect helped to maintain the integrity of gluten proteins and their adhesion to starch granules by preventing the breakage of disulfide bonds and the depolymerization of gluten macromolecules. It was also observed that yeast inactivation and glutathione release were reduced, resulting in improved air retention and air production capacity of the dough. This, in turn, led to a more appealing volume and texture quality of the finished bread.

Insights into the enhancement mechanism of immersion resistance of cooked noodles induced by wheat flour post-ripening: The view from protein cross-linking

To overcome the problem that takeaway noodles possessed poor immersion resistance, in this study noodles were prepared from post-ripened wheat flour, and changes in textural properties, protein components, and water status of noodles were determined. The firmness and tensile distance of noodles were gradually increased by 7.40%-35.88% when wheat flour was post-ripened for 20-40 d. Afterwards, noodle textural qualities were slightly decreased. Compared with control groups, contents of glutenin macropolymer (GMP) and disulfide bonds were significantly (p<0.05) increased and protein network was also more compact, whereas the Glutenin/Gliadin ratio and free sulfhydryl groups content were significantly (p<0.05) reduced. Contents of sodium dodecyl sulfate extractable protein (SDSEP) were reduced by 3.22%-6.23%. Meanwhile, the decrease in A23 indicated that wheat flour post-ripening limited water-absorbing capacity of noodles during immersion. In conclusion, wheat flour post-ripening promoted the immersion resistance of noodles by inducing protein cross-linking, and the best post-ripening time was 20-40 d.

Influence of key component interactions in flour on the quality of fried flour products

In the field of food, the interaction between various components in food is commonly used to regulate food quality. Starches, proteins, and lipids are ubiquitous in the food system and play a critical role in the food system. The interaction between proteins, starches, and lipids components in flour is the molecular basis for the formation of the classical texture of dough, and has a profound impact on the processing properties of dough and the quality of flour products. In this article, the composition of the key components of flour (starch, protein and lipid) and their functions in dough processing were reviewed, and the interaction mechanism of the three components in the dynamic processing of dough from mixing to rising to frying was emphatically discussed, and the effects of the components on the network structure of dough and then on the quality of fried flour products were introduced. The analysis of the relationship between dough component interaction, network structure and quality of fried flour products is helpful to reveal the common mechanism of quality change of fried flour products, and provide a reference for exploring the interaction of ingredients in starch food processing.

Moderate regulation of wheat B-starch ratio: Improvement of molecular structure, spatial conformation, aggregation behavior of reconstituted fermented doughs and its processing suitability

Aiming to investigate the changes and effects of different particle sizes of wheat A/B starch during dough fermentation, the present study reconstituted A/B starch fractions in ratios of 100:0, 75:25, 50:50, 25:75, and 0:100, further blended with gluten and subjected to slight (20 min), medium (30 min), and high (60 min) fermentation processes by yeasts. Results showed that fermentation gas production promoted gluten network extension, inducing starch granule exposure and dough surface roughness. Also, fermentation fractured protein intermolecular disulfide bonds and decreased α-helix and β-folded structure content, contributing to GMP, LPP, and SPP content decreases. Moreover, moderately increasing the B-starch ratio in the dough can improve gluten network stability, continuity, and air-holding capacity. The 25A-75B steam bread exhibited optimal processing suitability (better morphology, texture, and quality) due to its higher GMP and polymer protein content with lower free sulfhydryl and monomeric protein content. Further, conformational relationships indicated the key indicators influencing dough products' properties were free sulfhydryl content, GMP content, protein molecular weight distribution, and secondary structure. The obtained findings contributed to understanding the effect of wheat starch granule size distribution on dough processing behavior, and future targeted breeding for wheat cultivars with high B-starch content for improved fermentation pasta product qualities.

A Review of the Impact of Starch on the Quality of Wheat-Based Noodles and Pasta: From the View of Starch Structural and Functional Properties and Interaction with Gluten

Starch, as a primary component of wheat, plays a crucial role in determining the quality of noodles and pasta. A deep understanding of the impact of starch on the quality of noodles and pasta is fundamentally important for the industrial progression of these products. The starch structure exerts an influence on the quality of noodles and pasta by affecting its functional attributes and the interaction of starch-gluten proteins. The effects of starch structure (amylopectin structure, amylose content, granules size, damaged starch content) on the quality of noodles and pasta is discussed. The relationship between the functional properties of starch, particularly its swelling power and pasting properties, and the texture of noodles and pasta is discussed. It is important to note that the functional properties of starch can be modified during the processing of noodles and pasta, potentially impacting the quality of the end product, However, this aspect is often overlooked. Additionally, the interaction between starch and gluten is addressed in relation to its impact on the quality of noodles and pasta. Finally, the application of exogenous starch in improving the quality of noodles and pasta is highlighted.

Effect of starch granule size on the properties of dough and the oil absorption of fried potato crisps

Starch is a key element in fried potato crisps, however, the effect of starch granule size on oil absorption of the product have yet to be fully investigated. The study explored the impact of starch granule size on both the dough characteristics and oil absorption in potato crisps. The dough composed of small-sized potato granules showed more compact and uniform network system. Additionally, X-ray Microscope analysis showed that potato crisps prepared with small-sized potato granules had limited matrix expansion and fewer pores, cracks, and voids. The small-sized potato and small-sized wheat starches granule addition crisps displayed a significantly greater average cell thickness (52.05 and 53.44 μm) than other samples, while exhibiting notably lower average porosity (61.37 % and 60.28 %) compared to other samples. Results revealed that potato crisps with medium and small potato granules had 12.91 % and 21.92 % lower oil content than those containing large potato starch. Potato crisps with B-type wheat starch showed 16.36 % less oil absorption than those with A-type wheat starch. Small-sized starches significantly influence the dough structure and contribute to the reduction of oil absorption in fried products. The generated insights may provide monitoring indexes for cultivating potato varieties with low oil absorption.

Folding during sheeting improved qualities of dried noodles through gluten network proteins

The texture properties after cooking for 12 min were selected to optimize the sheeting parameters, and the results were verified using the comprehensive quality of dried noodles. The distribution of water, characteristics of gluten protein, and interaction between gluten network and starch were analyzed to clarify the mechanism of the quality of dried noodles. Results showed that the optimal folding angle was 45°, under this condition, the largest anti-extension displacement perpendicular to the rolling direction and the smallest cooking loss were obtained. The hardness and smoothness of cooked noodles increased by about 14% to 17%. Further, the transverse relaxation time of strongly bound water significantly decreased, while the relative content and binding strength increased. The hydrogen bonds and α-helix contents increased by about 68.8% and 53.1%, respectively. Folding and sheeting enhanced the combination of starch granules and gluten network causing, decreased in the average length and porosity of the gluten network. It is depicted from the results that the method of optimizing the sheeting process based on the texture of dried noodles cooked for 12 min was feasible. And the 45° folding and sheeting could help to improve the quality of dried noodles.

Effects of oil and heating on the physicochemical and microstructural properties of gluten-starch dough

Oil has crucial applications for improving the quality of some wheat products during dough formation and heat-processing. Herein, the influence of oil modification and thermal-mechanical treatment on dough prepared mainly with wheat starch and gluten was investigated. Oils with different structures addition reduced the hardness but improved the tensile strength of dough and inhibited starch retrogradation. Oil also reduced the disulfide bond, hydrogen bond and hydrophobic interactions whilst changed the rheology of dough. The X-ray diffraction patterns were characterised by new weak peaks at approximately 12.9°, and 19.8°, indicating that thermal-mechanical treatment promoted the formation of V-type complexes. Oil modification impaired dough short-range ordered structure, but prevented part starch granule crystallinity degradation caused by thermal-mechanical treatment. Scanning electron microscopy revealed oil modification and thermal-mechanical treatment synergistically affected starch-gluten agglomeration. Our findings contributed to elucidate the influence of oil modification and thermal-mechanical treatment on dough functionality.

Gluten-starch microstructure analysis revealed the improvement mechanism of Triticeae on broomcorn millet (Panicum miliaceum L.)

Understanding the mechanism by which Triticeae improves the quality of broomcorn millet (BM) is key to expanding the use of this crop to address food crises and food security. This study aimed to explore the effects of Triticeae on the disulfide bonds, secondary structures, microstructure, and rheological properties of BM dough, and to investigate the potential food applications of BM. Gluten protein, intermolecular SS, and β-Sheets content of the reconstituted doughs were significantly improved compared with BM dough, which improved disorderly accumulation of starch and gluten-starch interaction in BM dough. CLSM analysis showed that broomcorn millet-common wheat (BM-CW) and broomcorn millet-durum wheat (BM-DW) also possessed larger protein areas, smaller lacunarities, and better gluten-starch interactions in the reconstituted doughs. Disulfide bonds were positively correlated with the gluten network structure, and more disulfide bonds were formed in BM-CW (3.86 μmol/g), which promoted stronger mechanical resistance in BM-CW. Therefore, the combination of BM flour with CW and DW flours had better dough elasticity and stability. Finally, a potential evaluation and optimization scheme for BM as a cooked wheaten food is proposed to improve the reference for future food security and dietary structure adjustment of residents.

Impact of wheat bran dietary fiber on gluten aggregation behavior in dough during noodle processing

We herein evaluated the impact of adding wheat bran dietary fiber (WBDF) on the aggregation behavior of gluten in dough at various stages of the noodle-making process. Scanning electron microscopy and confocal laser scanning microscopy images confirmed the effective insertion of WBDF particles into the gluten matrix. Importantly, the gap between WBDF and gluten widened during the rolling process. The addition of WBDF led to a reduction in glutenin macropolymer (GMP) content and an elevation in sulfhydryl content, induced the depolymerization behaviors at the molecular level. Additionally, it facilitated the conversion of α-helices and β-turns into β-sheets and random coils within the dough. Moreover, the processing and addition of WBDF contributed to a decrease in weight loss, whereas the degradation temperature remained constant. Resting decreased the sulfhydryl content, whereas sheeting and cutting increased it, further fostering protein depolymerization in the presence of WBDF. These actions significantly increased the β-sheets and random coils content at the expense of β-turns and α-helices content. Significantly, controlled processing emerged as a crucial factor in enhancing gluten depolymerization induced by WBDF in the dough. This comprehensive study provides a nuanced perspective on controlling dough processing to strike a balance between dietary fiber-rich and high-quality foods.

Bioactive Edible Gel Films Based on Wheat Flour and Glucose for Food Packaging Applications

In order to prepare bioactive edible gel films with enhanced properties, the feasibility of using wheat flour as a raw material with glucose added at several concentrations was studied in this investigation. Films were prepared with glucose concentrations of 0.5, 0.7 and 1 g/g of flour and characterized for their physicochemical properties, including water content, solubility, degree of swelling, chemical structure by FT-IR (ATR) spectroscopy, morphology by SEM microscopy, thermal properties by DSC, gas and water vapor permeability and antioxidant activity. Biodegradation studies were also carried out in soil for 27 days and evaluated by weight loss measurements. It was found that the gel film with the higher glucose concentration exhibits a homogeneous and continuous structure with no cracks and no fragility, accompanied by an increased thickness and solubility and a decreased degree of swelling compared to those with lower concentrations. The chemical structure of all films was verified. Moreover, the increase in glucose content leads to better gas barrier properties with lower oxygen, CO2 and water vapor transmission rates and increased water vapor permeability. A slightly elevated melting temperature was observed in the films with higher glucose content. Higher antioxidant activity was also associated with higher percentage of glucose. Finally, the biodegradation of the films ranged from 13 to nearly 70%. Therefore, it can be concluded that the addition of glucose to wheat flour in concentration up to 1 g/g could result in edible gel films with excellent properties to be used in food packaging applications.

Effect of sodium carbonate on the properties of seventy percent of Tartary buckwheat composite flour-based doughs and noodles and the underlying mechanism

The impact of Na2 CO3 on the properties of doughs and noodles containing 70% Tartary buckwheat flour was investigated. Low-field 1 H nuclear magnetic resonance showed the mobility of water in the doughs significantly declined with the addition content of alkali from 0% to 0.9%. Na2 CO3 promoted the transformation from free sulfhydryl groups to disulfide bonds in doughs because the sulfhydryl groups in cysteine preferred to form thiolate anion and then oxidate under alkaline conditions. As for non-covalent chemical interactions, a significant increase of hydrogen bonds and a decrease of hydrophobic interactions were observed after Na2 CO3 addition. Quantitative analysis of microstructure showed that more uniform and denser gluten networks with higher branching rate and shorter average protein length and width formed in the doughs with 0.3%-0.6% of Na2 CO3 . The aggregated glutenin macropolymer and enhanced protein structure led to significantly stronger tensile of Tartary buckwheat dough sheets, which could meet the demand of continuous processing in the factory. Dough with alkali had higher swelling power and pasting viscosities, contributing to higher water absorption, and improved textural attributes of cooked noodles. This study demonstrated the possibility of adding Na2 CO3 at a moderate level for promoting the sheeting, cooking, and eating properties of high Tartary buckwheat flour composite noodles.

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.

Regulating the composition and secondary structure of wheat protein through canopy shading to improve dough performance and nutritional index

Viscoelastic properties of gluten proteins critically determine the biscuit-making quality. However, cultivar genetics and light conditions closely regulate the composition of the gluten proteins. The impact of pre- and post-anthesis shading (60 %) on amino acid profile, gluten protein composition, secondary structure, dough performance, and biscuit-making quality were evaluated using four wheat cultivars that differ in gluten protein composition. Pre- and post-anthesis shading increased the contents of gliadin, by 35.8 and 3.1 %; glutenin, by 27.6 and 7.3 %; and total protein, by 21.7 and 10.6 %, respectively, compared with those of unshaded plants. Conversely, the ratios of glutenin/gliadin, ω-/(α,β + γ)-gliadin, and high-molecular-weight/low-molecular-weight glutenin subunits decreased with shading. Strong-gluten cultivars exhibited smaller declines in these parameters than weak-gluten cultivars. Secondary structure analysis of the wheat protein revealed that shading increased β-sheet content but decreased β-turn content. Changes in protein components and their secondary structures caused an increase in wet gluten content, dough development time, and gluten performance index, thereby decreasing the biscuit spread ratio. Shading stress increased the protein content and nutrition index but decreased the biological value of protein by 2.5 %. Transcriptomic results revealed that shading induced 139 differentially expressed genes that decreased carbohydrate metabolism and increased amino acid metabolism, involved in increased protein content. Thus, canopy shading improves dough performance and nutrition index by regulating the amino acid profiles, protein compositions, and secondary structures. The study provides key insights for achieving superior grain quality under global dimming.

Effects of glutenin and gliadin on the surface tackiness of frozen cooked noodles

The mechanism of glutenin and gliadin on the surface tackiness of recooked frozen cooked noodles (FCNs) is unclear. In this study, the effects of glutenin and gliadin addition on the surface tackiness of FCNs were investigated. The addition of glutenin and gliadin reduced the surface tackiness (3.60 and 3.50 N) of recooked FCNs stored for 0 min. The addition of glutenin increased the rigidity of the gluten network and the compactness of FCNs and made the FCNs have a moisture-distribution with multilayers. The addition of gliadin increased the tensile distance of FCNs, restricted water migration during frozen storage, and increased the membranous structure of the gluten network to wrap starch particles. Glutenin had a stronger effect on reducing the surface tackiness of FCNs than gliadin. In the future, the synergistic effects of different proportions of glutenin and gliadin on the gluten network of FCNs could be further studied.

Starch granules and their size distribution in wheat: Biosynthesis, physicochemical properties and their effect on flour-based food systems

Starch is a vital component of wheat grain and flour, characterized by two distinct granule types: A-type starch (AS) with granules larger than 10 µm in diameter, and B-type starch (BS) with granules measuring no more than 10 µm in diameter. This review comprehensively evaluates the isolation, purification, and biosynthesis processes of these types of granules. In addition, a comparative analysis of the structure and properties of AS and BS is presented, encompassing chemical composition, molecular, crystalline and morphological structures, gelatinization, pasting and digestive properties. The variation in size distribution of granules leads to differences in physicochemical properties of starch, influencing the formation of polymeric proteins, secondary and micro-structures of gluten, chemical and physical interactions between gluten and starch, and water absorption and water status in dough system. Thus, starch size distribution affects the quality of dough and final products. In this review, we summarize the up-to-date knowledge of AS and BS, and propose the possible strategies to enhance wheat yield and quality through coordinated breeding efforts. This review serves as a valuable reference for future advancements in wheat breeding.

Humic acid chelated selenium is suitable for wheat biofortification

BACKGROUND

Selenium rich bread is a good carrier of selenium, but the inorganic selenium used in the actual production process is toxic. It is necessary to develop a new green bread production technology. The extraction and utilization of humic acid chelated selenium from selenium-rich soil is beneficial for reducing resource waste and pollution without destroying the soil ecosystem in selenium-deficient areas. Sodium selenite and nanoselenium were selected as controls because they are commonly used as selenium agronomic enhancers in production.

RESULTS

Humic acid chelated selenium can be absorbed and accumulated by wheat leaves, and humic acid chelated selenium had no significant effect on wheat yield, which was also shown in the treatments with nanoselenium and sodium selenite. Excessive accumulation of selenium in wheat grains can lead to a deterioration of processing quality. Among them, the use of excessive nanoselenium at the filling stage inhibited the accumulation of wheat grain protein, whereas humic acid chelated selenium is beneficial to grain protein accumulation and has the least negative effect on the processing quality. The accumulation of excessive selenium in wheat seeds had a negative effect on seed germination and growth; specifically, the seed vigor of wheat treated with humic acid chelated selenium was higher than that of untreated wheat.

CONCLUSION

Humic acid chelated selenium is particularly suitable for the whole process of Se-enriched bread wheat production. The seed vigour of wheat treated with humic acid chelated selenium, which supplied a moderate amount of selenium, was higher than that of untreated wheat. Conversely, the accumulation of excessive selenium in wheat seeds reduced germination and seedling growth. © 2023 Society of Chemical Industry.

Wheat starch particle size distribution regulates the dynamic transition behavior of gluten at different stages of dough mixing

This study investigated the morphology distribution, molecular structure, and aggregative properties variation of gluten protein during dough mixing stage and interpreted the interaction between starch with different sizes and protein. Research results indicated that mixing process induced glutenin macropolymer depolymerization, and promoted the monomeric protein conversion into the polymeric protein. Appropriate mixing (9 min) enhanced the interaction between wheat starch with different particle sizes and gluten protein. Confocal laser scanning microscopy images showed that a moderate increase in B-starch content in the dough system contributed to forming a more continuous, dense, and ordered gluten network. The 50A-50B and 25A-75B doughs mixed for 9 min exhibited a dense gluten network, and the arrangement of A-/B-starch granules and gluten was tight and ordered. The addition of B-starch increased α-helixes, β-turns, and random coil structure. Farinographic properties indicated that 25A-75B composite flour had the highest dough stability time and the lowest degree of softening. The 25A-75B noodle displayed maximum hardness, cohesiveness, chewiness, and tensile strength. The correlation analysis indicated that starch particle size distribution could influence noodle quality by changing the gluten network. The paper can provide theoretical support for regulating dough characteristics by adjusting the starch granule size distribution.

Changes Induced by Heat Moisture Treatment in Wheat Flour and Pasta Rheological, Physical and Starch Digestibility Properties

Wheat is one of the main crops that is cultivated and consumed in the world. Since durum wheat is less abundant and more expensive than other types, pasta producers can use common wheat by applying various techniques to achieve the desired quality. A heat moisture treatment was applied to common wheat flour, and the effects on dough rheology and texture, and pasta cooking quality, color, texture, and resistant starch content were evaluated. The results revealed that heat moisture treatment temperature and moisture content induced a proportional increase in visco-elastic moduli, dough firmness, pasta cooking solids loss, and luminosity, as they were higher compared to the control. The breaking force of uncooked pasta decreased when the flour moisture content increased, while the opposite trend was observed for resistant starch content. The highest resistant starch values were obtained for the samples treated at the lowest temperature (60 °C). Significant correlations (p < 0.05) were obtained between some of the textural and physical characteristics analyzed. The studied samples can be grouped in three clusters characterized by different properties. Heat moisture treatment is a convenient physical modification of starch and flours that can be employed in the pasta industry. These results underline the opportunity to enhance common pasta processing and final product functionality by using a green and non-toxic technique to develop new functional products.

Superior gluten structure and more small starch granules synergistically confer dough quality for high amylose wheat varieties

High amylose wheat (HAW) has potential health benefits but its dough structure is usually inferior. Wheat dough is a complex mixture and its structure is influenced by the physicochemical properties of gluten and starch. In this study, we investigated the starch granule development, gluten structure, starch properties, pasting, and thermal properties of flour, as well as the rheological properties of dough in wheat variety Xinong 836 with high amylose content (33.57%) and its parents. The results showed that Xinong 836 wheat starch contained more small starch granules, which was consistent with the microstructural results of starch granules in grain filling stage. Moreover, Xinong 836 wheat starch showed highest swelling power and water solubility. Importantly, the flour of Xinong 836 wheat had the highest protein content and wet gluten content and Xinong 836 wheat gluten showed highest β-sheets content and disulfide bond content than its parents Zhengmai 7698 and Xinong 979, which conferring to more compact microscopic networks of dough, thereby contributing to the higher peak viscosity (PV), final viscosity (FV), and setback viscosity (SB) in the flour of Xinong 836. Our finding elucidated that the stability of gluten and properties of starch synergistically affected the pasting and thermal properties of the flour paste, and the presence of more small starch granules contributed to dough with a rather dense structure in HAW Xinong 836. Thus, superior gluten structure and more small starch granules have synergistic effects on enhancing the gluten-starch interaction, thereby contributing to better dough quality.

Variation in Wheat Quality and Starch Structure under Granary Conditions during Long-Term Storage

As a globally distributed cereal, wheat is an essential part of the daily human dietary structure. Various changes in nutrient composition and starch structure can reflect the quality of wheat. In this study, we carried out a series of measurements to reveal the levels of wheat quality during long-term storage. We found that the deterioration of wheat was apparent after two years of storage: (1) the content of fatty acid increased from 12.47% to 29.02%; (2) the malondialdehyde content increased to 37.46%; (3) the conductivity significantly increased from 35.71% to 46.79%; and (4) other indexes, such as the amylopectin content, peak viscosity, and disintegration rate, increased noticeably during storage. Moreover, SEM images revealed a certain degree of damage on the surface of starch granules, and an X-ray diffraction (XRD) analysis showed A-type crystalline starch of wheat. Additionally, FTIR spectra suggested that the ratio of amylose and amylopectin decreased with a decreasing content of amylose and increasing content of amylopectin. The ratio of amylose and amylopectin can lead to variations in wheat machining characteristics. Therefore, wheat should be kept at an average of 20 °C with safe water content for less than two years to maintain reasonable quality.

Disomic 1M (1B) Triticum aestivum-Aegilops comosa Substitution Line with Favorable Protein Properties

Aegilops comosa (2n = 2x = 14, MM) contains many excellent genes/traits for wheat breeding. Wheat-Ae. comosa introgression lines have potential value in the genetic improvement of wheat quality. A disomic 1M (1B) Triticum aestivum-Ae. comosa substitution line NAL-35 was identified by fluorescence in situ hybridization and genomic in situ hybridization analysis from a hybridization cross between a disomic 1M (1D) substitution line NB 4-8-5-9 with CS N1BT1D. The observation of pollen mother cells showed that NAL-35 had normal chromosome pairing, suggesting that NAL-35 could be used for the quality test. NAL-35 with alien Mx and My subunits showed positive effects on some protein-related parameters including high protein content and high ratios of high-molecular-weight glutenin subunits (HMW-GSs)/glutenin and HMW-GS/low-molecular-weight glutenin subunits. The changes in gluten composition improved the rheological properties of the dough of NAL-35, resulting in a tighter and more uniform microstructure. NAL-35 is a potential material for wheat quality improvement that transferred quality-related genes from Ae. comosa.

Shading affects the starch structure and digestibility of wheat by regulating the photosynthetic light response of flag leaves

Heavy haze-induced decreases in solar radiation represent an important factor that affects the structural properties of starch macromolecules. However, the relationship between the photosynthetic light response of flag leaves and the structural properties of starch remains unclear. In this study, we investigated the impact of light deprivation (60 %) during the vegetative-growth or grain-filling stage on the leaf light response, starch structure, and biscuit-baking quality of four wheat cultivars with contrasting shade tolerance. Shading decreased the apparent quantum yield and maximum net photosynthetic rate of flag leaves, resulting in a lower grain-filling rate and starch content and higher protein content. Shading decreased the starch, amylose, and small starch granule amount and swelling power but increased the larger starch granule amount. Under shade stress, the lower amylose content decreased the resistant starch content while increasing the starch digestibility and estimated glycemic index. Shading during the vegetative-growth stage increased starch crystallinity, 1045/1022 cm^-1 ratio, starch viscosity, and the biscuit spread ratio, while shading during the grain-filling stage decreased these values. Overall, this study indicated that low light affects the starch structure and biscuit spread ratio by regulating the photosynthetic light response of flag leaves.

Effect of Mixing Time on Properties of Whole Wheat Flour-Based Cookie Doughs and Cookies

This study investigated if whole wheat flour-based cookie dough's physical properties were affected by mixing time (1 to 10 min). The cookie dough quality was assessed using texture (spreadability and stress relaxation), moisture content, and impedance analysis. The distributed components were better organized in dough mixed for 3 min when compared with the other times. The segmentation analysis of the dough micrographs suggested that higher mixing time resulted in the formation of water agglomeration. The infrared spectrum of the samples was analyzed based on the water populations, amide I region, and starch crystallinity. The analysis of the amide I region (1700-1600 cm^-1) suggested that β-turns and β-sheets were the dominating protein secondary structures in the dough matrix. Conversely, most samples' secondary structures (α-helices and random coil) were negligible or absent. MT3 dough exhibited the lowest impedance in the impedance tests. Test baking of the cookies from doughs mixed at different times was performed. There was no discernible change in appearance due to the change in the mixing time. Surface cracking was noticeable on all cookies, a trait often associated with cookies made with wheat flour that contributed to the impression of an uneven surface. There was not much variation in cookie size attributes. Cookies ranged in moisture content from 11 to 13.5%. MT5 (mixing time of 5 min) cookies demonstrated the strongest hydrogen bonding. Overall, it was observed that the cookies hardened as mixing time rose. The texture attributes of the MT5 cookies were more reproducible than the other cookie samples. In summary, it can be concluded that the whole wheat flour cookies prepared with a creaming time and mixing time of 5 min each resulted in good quality cookies. Therefore, this study evaluated the effect of mixing time on the physical and structural properties of the dough and, eventually, its impact on the baked product.

Characterization of sonicated gluten protein and subsequent rheological properties of model dough and noodles

BACKGROUND

The present study aimed to investigate the effects of the thermo-mechanical and rheological properties of a wheat gluten-sonicated model dough and noodles, as well as the effects of ultrasonic frequency (20, 28, 40, 68 and 80 kHz) on the functional properties and structural features of gluten.

RESULTS

Water absorption, stability and developmental time, and viscoelastic behavior of gluten-sonicated model dough were all found to be improved. Water absorption, tensile resistance and stretching distance of noodles increased markedly, whereas cooking loss decreased. Ultrasonication at different frequencies also significantly affected gluten structure, including its surface hydrophobicity, micro-network structure, and secondary and tertiary structures. These alterations then caused changes in its functional characteristics. Compared to untreated gluten, sonicated gluten exhibited significantly increased oil and water capacities (8.75-15.26% and 100.65-127.71% higher than the untreated gluten, respectively), foaming and emulsifying properties, and increased solubility (63.46-98.83% higher than control). In addition, these findings indicated that 40 kHz was the likely resonance frequency of the cavitation bubble in the gluten solution. However, sodium dodecyl sulfate-polyacrylamide gel electrophoresis electropherograms revealed that such treatments did not affect the molecular weight of gluten, which was also consistent with its unchanged disulfide bond content.

CONCLUSION

The present study clarified the impact of frequency on the properties of gluten and model dough. The best frequency for modification of gluten was 40 kHz. Collectively, these findings suggest that ultrasonic technology has the potential for use in modifying wheat gluten and commercial noodle processing. © 2022 Society of Chemical Industry.

Uncovering the genetic basis for quality traits in the Mediterranean old wheat germplasm and phenotypic and genomic prediction assessment by cross-validation test

The release of new wheat varieties is based on two main characteristics, grain yield and quality, to meet the consumer's demand. Identifying the genetic architecture for yield and key quality traits has wide attention for genetic improvement to meet the global requirement. In this sense, the use of landraces represents an impressive source of natural allelic variation. In this study, a genome-wide association analysis (GWAS) with PCA and kinship matrix was performed to detect QTLs in bread wheat for fifteen quality and agronomic traits using 170 diverse landraces from 24 Mediterranean countries in two years of field trials. A total of 53 QTL hotspots containing 165 significant marker-trait associations (MTAs) were located across the genome for quality and agronomical traits except for chromosome 2D. The major specific QTL hotspots for quality traits were QTL_3B.3 (13 MTAs with a mean PVE of 8.2%) and QTL_4A.3 (15 MTAs, mean PVE of 11.0%), and for yield-related traits were QTL_2B.1 (8 MTAs, mean PVE of 7.4%) and QTL_4B.2 (5 MTAs, mean PVE of 10.0%). A search for candidate genes (CG) identified 807 gene models within the QTL hotspots. Ten of these CGs were expressed specifically in grain supporting the role of identified QTLs in Landraces, associated to bread wheat quality traits and grain formation. A cross-validation approach within the collection was performed to calculate the accuracies of genomic prediction for quality and agronomical traits, ranging from -0.03 to 0.64 for quality and 0.46 to 0.65 for agronomic traits. In addition, five prediction equations using the phenotypic data were developed to predict bread loaf volume in landraces. The prediction ability varied from 0.67 to 0.82 depending on the complexity of the traits considered to predict loaf volume.

Striving for Stability in the Dough Mixing Quality of Spring Wheat under the Influence of Prolonged Heat and Drought

The effects of prolonged heat and drought stress and cool growing conditions on dough mixing quality traits of spring wheat (Triticum aestivum L.) were studied in fifty-six genotypes grown in 2017 and 2018 in southern Sweden. The mixing parameters evaluated by mixograph and the gluten protein characteristics studied by size exclusion high-performance liquid chromatography (SE-HPLC) in dough were compared between the two growing seasons which were very different in length, temperature and precipitation. The genotypes varying in gluten strength between the growing seasons (≤5%, ≤12%, and ≤17%) from three groups (stable (S), moderately stable (MS), and of varying stability (VS)) were studied. The results indicate that most of the mixing parameters were more strongly impacted by the interaction between the group, genotype, and year than by their individual contribution. The excessive prolonged heat and drought did not impact the buildup and mixing time expressed as peak time and time 1-2. The gluten polymeric proteins (unextractable, %UPP; total unextractable, TOTU) and large unextractable monomeric proteins (%LUMP) were closely associated with buildup and water absorption in dough. Major significant differences were found in the dough mixing parameters between the years within each group. In Groups S and MS, the majority of genotypes showed the smallest variation in the dough mixing parameters responsible for the gluten strength and dough development between the years. The mixing parameters such as time 1-2, buildup, and peak time (which were not affected by prolonged heat and drought stress) together with the selected gluten protein parameters (%UPP, TOTU, and %LUMP) are essential components to be used in future screening of dough mixing quality in wheat in severe growing environments.

Evolution of the morphological, structural, and molecular properties of gluten protein in dough with different hydration levels during mixing

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Changes in hydration level induced different gluten evolution patterns and dynamics.

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Appropriate mixing at high hydration levels results in a more uniform gluten network.

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Gluten network in highly hydrated dough was more susceptible to mechanical force.

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High hydration level induced more ordered conformation and depolymerization of GMP.

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PCA and CA revealed that hydration level has more influence than mixing degree.

To understand the formation process of dough with different hydration levels upon mixing and the response of dough rheology, the dynamic evolution of gluten protein was tracked and quantified at morphological, structural, and molecular levels. Both macroscopical and microscopic distribution images showed that partial and full hydration induced quick formation of a more compact gluten network compared with limited hydration. Gluten network in highly hydrated samples was more susceptible to the formation and collapse induced by mechanical force. SE-HPLC results indicated significant depolymerization of glutenin macropolymer (GMP) in fully and partially hydrated samples. Sufficient mixing was accompanied by the increase of ionic and hydrogen bonds, while excessive mixing increased exposure of free -SH. Higher hydration level induced more ordered secondary structure. Correlation and principal component analysis revealed the patterns and dynamics of gluten evolution during dough formation with different hydration levels, and their contribution to the changes in dough modulus.

Delineating the dynamic transformation of gluten morphological distribution, structure, and aggregation behavior in noodle dough induced by mixing and resting

To understand the formation of gluten network and its regulation on noodle qualities upon mixing and resting, the dynamic distribution and molecular transformation of gluten were tracked and quantified. Confocal laser scanning microscopy and scanning electron microscopy images showed that appropriate mixing (8 min) and resting (60 min) induced a compact gluten network with higher gluten junctions. Both height and width of protein molecular chains were increased by hydration during mixing and reduced after excessive resting (90 min). According to the size exclusion/reversed phase-HPLC profiles, mixing induced slight depolymerization of large glutenin polymer, and α-gliadin subunits were more susceptible to polymerization after appropriate mixing and resting. Increased mixing time was accompanied by the strengthening of ionic and hydrogen bonds, and the weakening of hydrophobic interaction. PCA and correlation analysis revealed the accurate regulation of mixing and resting induced dynamic distribution and evolution of gluten on the macroscopic noodle qualities.

Characterization of Sorghum Processed through Dry Heat Treatment and Milling

Sorghum grain nutritional quality can be enhanced by applying dry heat treatments. The purpose of this study was to investigate the effects of dry heat treatment at two temperatures (121 and 14 °C) with three fractionation factors (S fraction < 200 μm, M fraction 200–250 μm and, L fraction > 300 μm) on sorghum flour chemical and functional properties, to optimize processes by means of a desirability function, and to characterize the optimal products. Treatment temperature negatively affected oil- and water-absorption capacity, protein and moisture contents, while the opposite trend was obtained for hydration capacity, swelling power, emulsifying properties, fat, ash, and carbohydrate content. Sorghum flour fractions positively influenced the hydration and water-retention capacities, emulsifying properties, and protein and carbohydrate content, while oil absorption, swelling power, fat, ash, and moisture were negatively affected. The optimal processing determined for each fraction was heat treatment at 121.00 °C for S fraction, 132.11 °C for M, and 139.47 °C for L. Optimal product characterization revealed that the color, bioactive properties, and protein and starch structures of the optimal samples had changed after heat treatment, depending on the fraction. These findings could be helpful for the cereal industry, since sorghum flour could be an alternative for conventional crops for the development of new products, such as snacks, baked goods, and pasta.

Recombinant Rice Quiescin Sulfhydryl Oxidase Strengthens the Gluten Structure through Thiol/Disulfide Exchange and Hydrogen Peroxide Oxidation

Recombinant rice quiescin sulfhydryl oxidase (rQSOX) has the potential to improve the flour processing quality, but the mechanisms remain unclear. The effects of rQSOX on bread quality, dough rheology, and gluten structure and composition, with glucose oxidase as a positive control, were investigated. rQSOX addition could improve the dough processing quality, as proved by enhanced viscoelastic properties of dough as well as a softer crumb, higher specific volume, and lower moisture loss of bread. These beneficial effects were attributed to gluten protein polymerization and gluten network strengthening, evidenced by the improved concentration of SDS-insoluble gluten and formation of large gluten aggregates and the increased α-helix and β-turn conformation. Furthermore, decreased free sulfhydryl and increased dityrosine in gluten as well as improved H₂O₂ content in dough suggested that the rQSOX dough strengthening mechanism was mainly based on the formation of disulfide bonds and dityrosine cross-links in gluten by both thiol/disulfide direct exchange and hydrogen peroxide indirect oxidation pathways.

Study of Noodle Quality Based on Protein Properties of Three Wheat Varieties

Waxy wheat offers unique benefits in food processing, including improving the smoothness and performance of the product. However, waxy wheat is not yet commercially available. The protein characteristics, including the protein content, subunit distribution, secondary structure, chemical interactions, and microstructure of the gluten, were explored to realize the full potential of waxy wheat. The results showed that the noodles prepared from waxy wheat had a gentle and glutinous texture compared with GY2018 and YM13. Partial-waxy and waxy wheat had a lower gluten index and glutenin macropolymer (GMP) content than GY2018, indicating a reduced gluten strength. Confocal laser scanning microscopy (CLSM) images showed that the starch granules were not securely attached to the partial-waxy and waxy wheat protein matrix. In addition, the waxy protein chains appeared more elongated and they weakened the protein network. In particular, HMW-GS subunit 2 + 12 may be the essential cause of the weak dough from SKN1. Compared with GY2018 and YM13, SKN1 had the highest number of free sulfhydryl groups. Rather than ionic bonds, hydrophobic interactions increased the gluten network in GY2018, YM13, and SKN1. The weak molecular forces in the gluten will result in a soft noodle texture.

Rheological, microstructure and mixing behaviors of frozen dough reconstituted by wheat starch and gluten

The effects of starch and gluten on the physicochemical properties of frozen dough were studied using reconstituted flour. The profiles of frozen dough were studied by Mixolab, rheometer, scanning electron microscopy (SEM), confocal laser scanning microscopy (CLSM), differential scanning calorimetry (DSC) and Fourier transform infrared spectroscopy (FTIR). Results revealed that starch, rather than gluten, played a decisive role in mixing properties. The breakdown and aggregation of the gluten network structure as well as the formation of β-turns and β-sheets in the frozen dough would be aggravated by the freezing of wheat starch. Smaller wheat starch granules (B-Type granules) affected the secondary structure of gluten network more than larger granules (A-Type granules), resulting in greater rheological property changes. The viscoelastic properties and freezable water content of frozen dough were more influenced by the freezing of gluten.

Effects of Quinoa Flour on Wheat Dough Quality, Baking Quality, and in vitro Starch Digestibility of the Crispy Biscuits

Quinoa is a pseudo-cereal which has excellent nutritional and functional properties due to its high content of nutrients, such as polyphenols and flavonoids, and therefore quinoa serves as an excellent supplement to make healthy and functional foods. The present study was aimed to evaluate the quality characteristics of wheat doughs and crispy biscuits supplemented with different amount of quinoa flour. The results showed that when more wheat flour was substituted by quinoa flour, proportion of unextractable polymeric protein to the total polymeric protein (UPP%) of the reconstituted doughs decreased and the gluten network structure was destroyed at a certain substitution level. The content of B-type starch and the gelatinization temperature of the reconstituted flours increased. The storage modulus, loss modulus, development time, and stability time of the dough increased as well. Moreover, hardness and toughness of the formulated crispy biscuits significantly decreased. Analyses suggested that starch digestibility was reduced and resistant starch content increased significantly. Taken together, quinoa flour improved dough rheological properties, enhanced the textural properties, and increased resistant starch content in crispy biscuits, thus adding to high nutritional value.

Effect of Highland Barley on Rheological Properties, Textural Properties and Starch Digestibility of Chinese Steamed Bread

Highland barley has a different composition and structure to other crops. It has higher contents of total polyphenol (TPC), total flavonoid (TFC) and β-glucan, which can be supplemented to improve the nutrition of wheat-flour-based food. In this study, the flours of three different grain-colored highland barley varieties Beiqing 6 (BQ), Dulihuang (DLH), and Heilaoya (HLY), were added to Jimai60 (JM, a wheat variety with medium gluten) wheat flour at different substitution levels to investigate their effects on the unextractable polymeric protein (UPP) content, micro-structure, rheological properties and mixing properties of dough, and the color, texture, flavor, and in vitro digestion of Chinese steam bread (CSB). The results showed that the moderate substitution of highland barley (20%) increased the UPP%, optimized the micro-structure of gluten, and improved its rheological properties by increasing dough viscoelasticity. The CSBs made from the composite flours exhibited a similar specific volume, cohesiveness, springiness and resilience to wheat CSB, while the firmness of composite CSBs (particularly JM-HLY-20) was delayed during storage. Importantly, the addition of highland barley increased the contents of TPC, TFC and β-glucan, but decreased the in vitro starch digestibility of CSBs. A sensory evaluation showed that JM-HLY CSB was the most preferable. Taken together, highland barley can be used as a fine supplement to food products, with health-promoting properties.