Impact of wheat globulin addition on dough rheological properties and quality of cooked noodles

Effects of protein-glutaminase on the properties of glutinous rice flour, paste, and gel food: Based on the interactions between the deamidated protein and starch

In the present study, protein-glutaminase (PG) from Chryseobacterium proteolyticum was applied to improve the processing properties of glutinous rice flour (GRF). After PG modification, the degree of deamidation of glutinous rice protein (GRP) reached 13.6% at 2.0 h, with smaller particle size and decreased zeta potential. The interaction of GRP with starch in PG-modified GRF (PM-GRF) was changed, exhibiting in protein aggregates decreasing and exposure of starch on the surface of GRF. Compared with unmodified GRF (UM-GRF), the solubility and turbidity of PM-GRF were both increased. The rheological properties reflected that the viscosity of PM-GRF paste was increased, and the freeze-thaw stability was also enhanced. Moreover, the textural characteristics showed that the hardness of PM-GRF balls remarkably reduced and the springiness increased. These results indicate that deamidation by PG could be an efficient method for improving characteristics of GRP and GRF.

Effect of oleic acid-rich rapeseed oil on the physicochemical, rheological, and structural characteristics of wheat dough

Some wheat-based foods require different doses of oil to moderate quality of dough during processing and the influence mechanisms remain unclear. Therefore, the effect of rapeseed oil addition on physicochemical characteristics and fine structure of dough and underlying mechanism were elucidated by rheometer, scanning microscope and molecular spectroscopic method. Results showed that compared with native dough (without exogenous rapeseed oil), the addition of rapeseed oil changed the fine structure, improved extensibility, but reduced viscoelasticity of the dough. Moreover, high addition especially 20 wt% oil (based on wheat flour) significantly changed gelatinization and retrogradation behaviors of the dough, whilst disrupted gluten network and increased random coil content (32.1%) of dough except that decreased its α-helix (21.2%), β-sheet (23.1%), disulfide bond (7.9 μmol/g) compared with native dough which were 16.3%, 29.2%, 33.1%, 11.0 μmol/g, respectively. Results in the study could provide a certain understanding for application of vegetable oils in wheat-based products.

Quantitative proteomic analysis for characterization of protein components related to dough quality and celiac disease in wheat flour, dough, and heat-treated dough

High-sensitivity 4D label-free proteomic technology was used to identify protein components related to gluten quality and celiac disease (CD) in strong-gluten wheat cultivar KX 3302 and medium-gluten wheat cultivar BN 207. The highly expressed storage protein components in KX3302 were high-molecular-weight-glutenin-subunits (HMW-GSs), α-gliadin, and globulin, whereas those in BN207 were γ-gliadin, low-molecular-weight-glutenin-subunits (LMW-GSs) and avenin-like proteins. In addition, BN207 had more upregulated metabolic proteins than KX3302. The abundance of storage proteins increased during dough formation. After heat treatment, the upregulated proteins accounted for 57.53 % of the total proteins, but the downregulated storage proteins accounted for 79.34 % of the total storage proteins. In cultivar KX3302, CD proteins mainly included α-gliadin and HMW-GSs, whereas in BN207, they were mainly γ-gliadin and LMW-GSs. Thermal treatment significantly reduces the expression levels of CD-related proteins. These findings provide a new perspective on reducing the content of CD-related proteins in wheat products.

Effect of egg white protein on the protein structure of highland barley noodles during processing

The effect of egg white protein on the protein structure of highland barely noodles during processing was investigated, and the underlying mechanism was examined. Egg white protein significantly influenced the stress relaxation of highland barley dough. 1% and 2% egg white protein improved the cooking and textural properties of highland barely noodles. During mixing and sheeting, it improved the structure of the protein network by promoting protein aggregation and cross-linking, whereas its effect on non-covalent interactions was quite different. During cooking, egg white protein promoted protein aggregation and cross-linking via heat-induced polymerization, and the distribution regularity of the protein network was improved as its flexibility diminished. The protein structure of highland barely noodles during processing was closely related to the addition amount of egg white protein, and the cooking, textural, and chemical interactions of highland barely noodles during processing changed considerably when more than 3% egg white protein was added.

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.

Alleviative effects of mannosylerythritol lipid-A on the deterioration of internal structure and quality in frozen dough and corresponding steamed bread

The effects of mannosylerythritol lipid-A (MEL-A) on the quality of frozen dough and corresponding steamed bread were investigated. The results revealed that the rheological properties of frozen dough were improved with the increment of MEL-A (0%-2.0%). Adding 1.5% and 2% MEL-A significantly reduced the moisture migration and enhanced the water-holding capacity of the frozen dough. Microstructure observation demonstrated that high levels of MEL-A enabled more starch granules to be embedded in the dough network. A series of product quality assessments illustrated that frozen dough steamed bread containing 2.0% of MEL-A had the largest specific volume (2.981 mL/g), the highest springiness (77.47%), more uniform and porous crumb structure. Moreover, MEL-A exhibited a positive effect on steamed bread's flavor profile, which was explored for the first time in this study. Hence, these results suggested that MEL-A has promising applications as a novel dough improver in the food industry.

Effect of heat treatment on conformation and aggregation properties of wheat bran dietary fiber-gluten protein

To understand the heat mediated cross-linking mechanism of gluten in the presence of wheat bran dietary fiber (WBDF), the effect of heat treatment on conformation and aggregation properties of wheat bran dietary fiber-gluten protein was comparatively investigated in this study. The results showed G' and G" increased after adding WBDF, then decreased after heating. The SE-HPLC, chemical interaction and surface hydrophobicity analysis revealed the WBDF participated in the rearrangement of intermolecular interactions and induced depolymerization behavior behavior of gluten via disulfide and non-covalent bonds at low temperatures (25 °C and 60 °C), but heating (at 95 °C) promoted these interactions via disulfide bonds. Besides, changes in the secondary structure of gluten protein induced by WBDF during heating were correlated with the steric hindrance and hydroxyl groups on WBDF. These results suggested that WBDF impeded the cross-linking and aggregation of gluten through the rearrangement of chemical bonds and physical entanglements, then this effect was weakened at high temperatures, most likely by improving the disulfide bonds among gluten proteins. This study consummates the understanding of the cross-linking mechanisms of gluten with WBDF during heating, and provides the theoretical basis for improving the quality and acceptability of whole wheat-based products.

Determination and Analysis of Composition, Structure, and Properties of Teff Protein Fractions

To develop teff-based food products with acceptable quality, the composition, structure, and properties of teff protein fractions should be better understood. In this study, teff proteins were extracted, and their protein composition, structure, and properties were calculated, analyzed, and compared with those of wheat gliadin and glutenin. Results showed that teff flour contained 9.07% protein, with prolamin as its main protein fraction. The isoelectric points of albumin, globulin, prolamin, and glutelin were at pH 3.6, 3.0, 4.4, and 3.4, respectively. Teff prolamin and glutelin showed a significant difference in amino acids and free energy of hydration compared to wheat gliadins and glutenins. The protein chain length of teff prolamins was smaller than that of wheat gliadins, and teff glutelins lacked high molecular weight glutelin subunits. Teff prolamin had the highest α-helices content (27.08%), whereas no random coils were determined, which is different from wheat gliadin. Teff glutelin had a lower content of β-turn than wheat glutenin, and no α-helices were determined in it. Teff prolamin and glutelin had lower disulfide bond content and surface hydrophobicity. Teff prolamin had significantly higher thermal stability than wheat gliadin, whereas the thermal stability of teff glutelin was significantly lower than that of wheat glutenin.

Genetic control and prospects of predictive breeding for European winter wheat's Zeleny sedimentation values and Hagberg-Perten falling number

KEY MESSAGE

Sedimentation values and falling number in the last decades have helped maintain high baking quality despite rigorous selection for grain yield in wheat. Allelic combinations of major loci sustained the bread-making quality while improving grain yield. Glu-D1, Pinb-D1, and non-gluten proteins are associated with sedimentation values and falling number in European wheat. Zeleny sedimentation values (ZSV) and Hagberg-Perten falling number (HFN) are among the most important parameters that help determine the baking quality classes of wheat and, thus, influence the monetary benefits for growers. We used a published data set of 372 European wheat varieties evaluated in replicated field trials in multiple environments. ZSV and HFN traits hold a wide and significant genotypic variation and high broad-sense heritability. The genetic correlations revealed positive and significant associations of ZSV and HFN with each other, grain protein content (GPC) and grain hardness; however, they were all significantly negatively correlated with grain yield. Besides, GPC appeared to be the major predictor for ZSV and HFN. Our genome-wide association analyses based on high-quality SSR, SNP, and candidate gene markers revealed a strong quantitative genetic nature of ZSV and HFN by explaining their total genotypic variance as 41.49% and 38.06%, respectively. The association of known Glutenin (Glu-1) and Puroindoline (Pin-1) with ZSV provided positive analytic proof of our studies. We report novel candidate loci associated with globulins and albumins-the non-gluten monomeric proteins in wheat. In addition, predictive breeding analyses for ZSV and HFN suggest using genomic selection in the early stages of breeding programs with an average prediction accuracy of 81 and 59%, respectively.

Starch-based noodles: Current technologies, properties, and challenges

Starch noodles are gaining interest due to the massive popularity of gluten-free foods. Modified starch is generally used for noodle production due to the functional limitations of native starches. Raw materials, methods, key processing steps, additives, cooking, and textural properties determine the quality of starch noodles. The introduction of traditional, novel, and natural chemical additives used in starch noodles and their potential effects also impacts noodle quality. This review summarizes the current knowledge of the native and modified starch as raw materials and key processing steps for the production of starch noodles. Further, this article aimed to comprehensively collate some of the vital information published on the thermal, pasting, cooking, and textural properties of starch noodles. Technological, nutritional, and sensory challenges during the development of starch noodles are well discussed. Due to the increasing demands of consumers for safe food items with a long shelf life, the development of starch noodles and other convenience food products has increased. Also, the incorporation of modified starches overcomes the shortcomings of native starches, such as lack of viscosity and thickening power, retrogradation characteristics, or hydrophobicity. Starch can improve the stability of the dough structure but reduces the strength and resistance to deformation of the dough. Some technological, sensory, and nutritional challenges also impact the production process.

Effect of hydrocolloids on gluten proteins, dough, and flour products: A review

Hydrocolloids are among the most common components in the food industry, which are used for thickening, gel formation, emulsification, and stabilization. Previous studies have also found that hydrocolloids can affect the structures and properties of gluten proteins, dough, and flour products. In this review, hydrocolloids were separated into three categories: anionic, nonionic, and other hydrocolloids, and reviewed the effects of common hydrocolloids on gluten proteins, dough, and flour products. Hydrocolloids can affect the structures and properties of gluten proteins through gluten-hydrocolloids interaction, secondary structures, disulfide bonds, environment of aromatic amino acids, and chemical bonds. The properties of dough are affected by rheological, fermentation, and thermomechanical properties. Hydrocolloids are widely used in bread, Chinese steamed bread, noodles, yellow layer cake, and so on, which mainly affect their appearance, texture, and aging speed. This comprehensive review provides a scientific guide for the development and utilization of hydrocolloids and their applications in flour products, and provides a theoretical basis for improving the processing characteristics of products.

Effect of White Kidney Bean Flour on the Rheological Properties and Starch Digestion Characteristics of Noodle Dough

The aim of this study was to investigate the effect of adding white kidney bean flour on the quality of noodles. We selected four different proportions of white kidney bean flour (10−40%) in wheat flour to make the noodles, after which the noodles were analysed for their physical and chemical properties. The statistical method of correlation analysis was used in this study. The results showed that the noodles’ sensory and textural characteristics significantly improved after adding white kidney bean flour (p < 0.05). Compared with the control, the noodles’ surface with white kidney bean flour was denser and smoother. Moreover, microstructural observations indicated that the noodles with white kidney bean flour showed a more continuous protein network. The in vitro digestion results showed that the addition of white kidney bean flour reduced the digestibility of the noodles. Low addition of the flour (10−20%) improved the quality of the noodles, whereas high amounts (30−40%) showed the opposite effect. In this study, the optimal amount of white kidney bean powder was found to be 20%.

Effect of soy protein hydrolysates incorporation on dough rheology, protein characteristic, noodle quality, and their correlations

Soy protein hydrolysates (SPHs) have bioactive and nutritional functions that can be used as fortifier of noodles. The objective of this study is to explore the effect of SPHs on dough rheology and noodle quality. Two kinds of SPHs, with a hydrolysis degree of 4.43% (SPH4) and 7.47% (SPH7), were added to wheat flour at a ratio of 5:95 to make dough and noodles. The addition of SPHs decreased the gluten yield, gluten index, peak viscosity, final viscosity, and setback of flour paste. Dough stability decreased, but the extensibility increased because of the addition of SPHs. SPHs decreased the high molecular weight glutenin subunits and SDS-unextractable polymeric protein proportion, and the results of scanning electron microscopy and atomic force microscopy also showed that the gluten network in SPH7 dough was more discontinuous than that in SPH4, suggesting a stronger negative effect of SPH7 on the formation of the gluten network compared to that of SPH4. The incorporation of SPHs decreased the hardness and springiness of cooked noodles but increased their cooking loss, protein loss, and water absorption. The correlation analysis showed that high molecular weight subunits and SDS-unextractable polymeric protein in SPH-fortified dough were positively correlated with the hardness, adhesiveness, springiness, cohesiveness, chewiness, resilience, force, and distance at break of noodles, and these texture properties of noodles were positively correlated with pasting, gluten, and farinographical properties of SPH-fortified flour. These results suggested that SPHs could improve some qualities of noodles, such as smoothness and cooking yield, and resist pasted starch aging. PRACTICAL APPLICATION: Soy protein hydrolysates have many bioactive functions. This study demonstrated the feasibility of incorporating soy protein hydrolysates into wheat flour to prepare noodles. The addition of soy protein hydrolysates gives noodles smoother mouthfeel and increases the cooking yield. The addition of soy protein hydrolysates decreases the setback value of flour paste, suggesting that soy protein hydrolysates may help to resist starch aging, which is favorable for starch-containing foods such as precooked noodles. Thus, soy protein hydrolysates possess potential applications in noodle products.

Impact of Fermented Wheat Bran Dietary Fiber Addition on Dough Rheological Properties and Noodle Quality

This study aimed to evaluate the effect of fermented wheat bran dietary fiber (FWBDF) on the rheological properties of the dough and the quality of noodles and to compare it with the effect of the unfermented WBDF (UWBDF). WBDF was fermented with Auricularia polytricha. The results showed that adding UWBDF/FWBDF increased the storage modulus G' and loss modulus G” of the dough, converted α-helices and β-turns into β-sheets and random coils, respectively, inhibited water flow, increased cooking loss, and decreased the maximum resistance in the noodles. The formed gluten network had a more random and rigid structure, resulting in the deterioration of the quality of noodles. Furthermore, the number of α-helices and the peak proportions of weakly bound water A₂₂ increased but the number of β-sheets and cooking loss decreased in the FWBDF group compared with the UWBDF group. FWBDF (≤4%) improved the hardness of noodles, while UWBDF decreased it. These changes indicated that fermentation could reduce the destructive effects of WBDF on the quality of noodles, providing a new perspective on balancing dietary fiber-rich and high-quality foods.

Effects of Wheat Bran Micronization on the Quality of Reconstituted Whole-Wheat Flour and Its Cooked Noodles

The particle size of wheat bran plays an important role in the quality of reconstituted whole-wheat flour and its products. The effects of wheat bran particle size on the quality of reconstituted whole-wheat flour and its cooked noodles were analyzed; the mean particle size (D50) of wheat bran ranged from 26.05 to 46.08 μm. Results show that the decreases in D50 of wheat bran induced the changes in the quality of whole-wheat flour and its noodles. Specifically, the damaged starch content, water absorption, and the solvent retention capacity of sodium carbonate and sucrose of whole-wheat flour increased at various degrees, while pasting viscosity decreased, and the gluten index and SDS-sedimentation volume increased first and then decreased. The cooking yield, cooking loss, and break rate of fresh noodles decreased first and reached a trough at D50 of 26.05 μm, and then increased. The adhesiveness of cooked noodles increased, the score of smoothness, taste, appearance, and color increased to a stable value, but the hardness, springiness, cohesiveness, resilience, firmness score, and elasticity score increased first and then decreased. These turning points of changing trends of indexes mostly occurred when the D50 of wheat bran was 26.51 μm. In conclusion, whole-wheat noodles with wheat bran of D50 of 26.51 μm addition exhibit better cooking, textural, and sensory properties than those with smaller or larger wheat bran. Excessive crushing of wheat bran not only costs highly in terms of energy, but also has a negative impact on the quality of the noodles.