Gluten Network Formation Research Articles

Interdisciplinary Projects Applied to Chemistry Lessons: Example of Chemistry Linked to Food Science.

An interdisciplinary project regarding the effect of ascorbic acid on bread dough's physico-chemical properties was proposed to bachelor students in chemistry and food sciences. Such an approach was proposed to develop both scientific and soft skills, in order to prepare students for their future working environment. Together, students deepened their knowledge regarding food science and chemistry. They were then able to plan and design experiments demonstrating the impact of gluten network formation and ascorbic acid influence onto bread dough and finished product characteristics. This way of teaching was very appreciated by students, nevertheless it highlighted the fact that the professors' investment was considerably high, and that good organization, alignment and preparation prior to the start of this project is key.

Effects of matcha and its active components on the structure and rheological properties of gluten

Matcha is a popular nutritious food ingredient with strong health benefits. The interplay between matcha and gluten is essential for developing high-quality matcha-noodles. Herein, the effects of matcha and its active components, l-theanine and tea polyphenol, on the structural and rheological properties of gluten had been investigated. The results showed that matcha weakened the dough strength by reducing disulfide bonds and hindering the formation of gluten network. However, l-theanine enhanced the ductility of dough by forming extra β-sheets and disulfide bonds, whereas tea polyphenol increased its toughness by forming numerous intermolecular hydrogen bonds with gluten to stabilize the “grid” structure. The underlying intermolecular mechanisms between gluten and l-theanine or tea polyphenol were clearly established. This study has provided valuable reference to produce nutritious noodles products with matcha or its active components.

Wheat protein disulfide isomerase improves bread properties via different mechanisms

Gluten network formation by the oxidation of glutenin sulfhydryl group majorly impacts the subsequent dough and bread properties, and an evolutionary list of chemical oxidants has been used as improvers in bread making. A systematic comparison between azodicarbonamide (ADA), Vc, wheat protein disulfide isomerase (wPDI) and disulfide bond formation protein C (DsbC) of their effects on the alveographic characters of dough and texture properties of subsequent bread was performed. Results show that wPDI improves dough alveographic characters and bread texture properties better in most aspects than other reagents. Free sulfhydryl analysis finds that addition of wPDI increased the free sulfhydryl content in both dough and bread. Compare with inorganic reagents and its bacterial homologue, improving the dough and bread properties with less oxidation of sulfhydryl lead to the proposal that wPDI acts by catalyzing the formation of rheologically active disulfide and reduction of inactive ones in a substrate specific manner.

Preparation of Cookies with Various Native Seaweeds Found on the Korean Coast

ABSTRACTWe investigated the quality characteristics of cookies prepared using different seaweeds native to the Korean coast. Flour made from four different seaweed species (Sargassum fulvellum, Enteromorpha linza, Codium fragile, and Hizikia fusiforme) was used to replace 5% of the regular flour while preparing the cookies. The seaweeds significantly affected solvent retention capacity, thus interfering with gluten network formation. Consequently, the addition of seaweed changed several variables in the cookies, such as moisture content, spread factor, and breaking stress. In sensory evaluation, cookies with Hizikia fusiforme were the most preferred, confirming the possibility of developing cookie products using this seaweed species.

Effect of moisturizing pre-treatment of dietary fibre preparations on formation of gluten network during model dough mixing – A study with application of FT-IR and FT-Raman spectroscopy

Two spectroscopic methods (FT-IR and FT-Raman spectroscopy) were used to determine whether 30-min moisturizing of DF preparations eliminates the structural effects of gluten dehydration. Studies were carried out on model flour that was mixed with non-moisturized and moisturized DF preparations (chokeberry, apple, cranberry, carrot, cacao, carob, flax and oat) in three concentrations: 3%, 6% and 9%. Comparison of the difference spectra concerning secondary structure showed that DF preparations prepared in both ways caused formation of different aggregated structures. Aggregates and pseudo-β-sheets were observed for non-moisturized preparations, while hydrated/extended-β-sheets were formed for moisturized preparations. 3%-addition of both kinds of preparations caused decrease in the amount of disulphide bridges in the g-g-g conformation. It suggests that not only dehydration process but also chemical interactions induced structural changes in gluten. Moreover, the number of S–S bonds in the g-g-g conformation remains constant regardless of increasing DF content for moisturized preparations characterized by high TDF content. Using of the moisturized preparations did not affect tyrosine and tryptophan parameters. The present results indicate that preliminary moisturizing cause different changes in the gluten structure and thus the treatment may improve the quality of the dough and bread supplemented with DF preparations.

Viscoelastic behavior of wheat dough with salt and a salt substitute studied by means of GlutoPeak®

AbstractBackground and objectivesThe effect of salt (NaCl) and a salt substitute (Pansalt®) on gluten network formation in the dough of 45 soft wheat cvs was studied by means of the GlutoPeak® device. Different salt levels (0%, 1.5%, and 2.5% NaCl and Pansalt®) were considered.FindingsThe presence of salts changes the dough viscoelastic behaviors. Two parameters, the maximum recorded torque occurring as gluten aggregates (BEM) and the peak maximum time (PMT), characterized the different cultivars, showing an increase of torque for doughs with salt (both salts) greater for weak flours than for strong flours, and a development time higher for strong flours. Moreover, the presence of salts showed a more significant effect on gluten structure in flours with high protein than with low protein content.ConclusionsThe GlutoPeak® curves well described the effect of salt on dough development. The salt effect on the flour mixing profile was found to be cv‐dependent and correlated to dough strength.Significance and noveltyThe GlutoPeak® viscometer has been used for the first time to study the effects of salts (sodium chloride and Pansalt) on dough performance in different soft wheat cvs. Data of GlutoPeak® parameters were statistically analyzed.

Microscopic investigation of the formation of a thermoset wheat gluten network in a model system relevant for bread making

SummaryAlthough the impact of heat on molecular properties of wheat gluten is well understood, changes in its microstructure have rarely been studied. Here, formation of the thermoset gluten network in a model system relevant for bread baking was studied with confocal laser scanning microscopy and protein network analysis. From 65 °C onwards, gluten converts from thick aligned protein strands in a highly branched and homogeneous network of small thin protein threads. Neither gliadin incorporation in the network nor application of aqualysin 1, the thermo‐active serine peptidase from Thermus aquaticus which recently has been reported to hydrolyse gluten proteins in dough only at temperatures exceeding 80 °C, impacts on the gluten microstructure. As starch causes structure setting itself and thereby decreases protein mobility, molecular scale changes in the gluten network at temperatures exceeding 80 °C brought about by aqualysin 1 do not impact its microstructure.

The effects of different additives on the physical properties of dumpling wrapper

The objective of the study was to investigate the effect of four different additives, such as potato hydroxypropyl distarch phosphate starch (HDPS), acetate starch (AS), trehalose (TRE) and oligofructose (OFS) on the colour, water loss, rheological behaviour, microstructure and texture of Chinese dumping wrappers. In addition to TRE, the addition of HDPS, AS and OFS had significantly effects (p < 0.05) on the colour of both frozen dumpling wrappers and steamed dumpling wrappers. The addition of HDPS, AS, TRE and OFS can significantly decrease (p < 0.05) the water loss of frozen dumpling wrappers compared to control samples. The addition of HDPS (6%), AS (6%), TRE (2%) and OFS (2%) had the highest G′, G″ compared to other samples. The microstructure from the cross section and tangent plane of the frozen dumpling wrappers and steamed dumpling wrappers showed that there were some small space among starch granules and the gluten network showed more compact with the addition of HDPS (6%), AS (6%) and TRE (2%) than the control samples. The addition of OFS (2%) can not change the microstrure of the frozen dumpling wrappers and significantly promote the formation of gluten network of steamed dumpling wrappers. The addition of HDPS, AS, TRE and OFS can influence the hardness, resilience and cohesiveness of steamed dumpling wrappers and improve their texture.

Effect of combining additional bakery enzymes and high pressure treatment on bread making qualities

Various enzymes are added to dough to improve the quality. Two enzymes are α-amylase and hemicellulase (bakery enzymes), whose substrates are damaged starch and insoluble dietary fiber, respectively. They improve the formation of gluten networks in the dough, resulting in a higher specific loaf volume (SLV). The use of high-pressure treatment has also increased as a substitute for heat treatment and various products are being processed utilizing high-pressure treatment. This study investigated the effect of combing bakery enzyme and high-pressure treatment on dough qualities. The optimal concentration of bakery enzymes and high-pressure level were determined using response surface methodology and optimization technique. Bread dough was prepared by the optimal condition, 0.20% of bakery enzyme and 43MPa of high-pressure treatment, and the bread dough was then baked. Optimal combining bakery enzyme and high-pressure treatment drastically improved bread making qualities such as increased SLV, higher concentrations of reducing sugar, and lower concentrations of damaged starch and insoluble dietary fiber compared to the control and to those that were only treated with bakery enzymes or high-pressure treatment, respectively. In addition, the bread with both bakery enzymes and high-pressure treatment showed improved micro structure in the crumb and maintained freshness longer.

Application of rich in β-glucan flours and preparations in bread baked from frozen dough.

This study aims to define the changes in the quality of bakery products depending on the β-glucan source and its contribution using bake-off technology. The examined bread was enriched with a 10% addition of oat flour, barley flour, oat fibre preparation, and barley fibre preparation. Bread was tested for rheological parameters, baking performance, hardness and springiness, water content, specific volume, porosity, crust and crumb colour, and β-glucan content. In the executed research, the adverse effect of this component on the formation of gluten network and hardness of the crumb was observed. In the double compression test, it was shown that the highest hardness on the day of baking was characterized by the bread with the addition of barley preparation. The fastest rate of staling was observed in the bread with additional barley flour that was affected by the highest amount of β-glucan. A significant decrease of the β-glucan level was also found during the technological bake-off process, which can be explained by the activity of enzymes.

Development of a novel model dough based on mechanically activated cassava starch and gluten protein: Application in bread

This study focused on the development of a novel model dough for leavened food production, which was obtained by blending gluten protein with damaged cassava starch (DCS) induced by mechanical activation (MA). The characteristics of model dough and the interaction between DCS and gluten were investigated, and the quality of bread made from the model dough was also evaluated. The results showed that both the addition of gluten and the increased damage of DCS could improve the strength of model dough. The damage of cassava starch prevented the formation of gluten network. The enhanced DCS-gluten interaction had an impact on the performance of dough, attributing to the interaction of hydrogen bonds between both of them. Moderate interaction was required to obtain the bread with desired quality, and MA for moderating structural damage to starch was an effective approach in promoting the interaction between starch and gluten protein.

Effect of wheat flour replacement with potato powder on dough rheology, physiochemical and microstructural properties of instant noodles

Wheat flour was replaced with potato powder (P.P) at 5 levels of 20%, 30%, 40%, 50%, and 60% w/w to make instant noodles. The results showed that storage modulus (Gʹ) and loss modulus (Gʺ) decreased when P.P was part of the dough. The addition of P.P inhibited the formation of gluten network. The redness (a*) and yellowness (b*) of dough were increased with the increasing amount of P.P. Moreover, the gelatinization properties such as peak viscosity, trough, breakdown, and final viscosity decreased while pasting temperature fluctuated when >40% P.P was added. Moreover, moisture content, cooking loss, and water absorption increased significantly (p < 0.0.5) when 40% P.P was added. Furthermore, scanning electron microscopy showed that the gluten network became weak, with uneven voids, and more starch granules were observed when P.P was added. The findings suggested the feasibility of adding 40% P.P in noodles for acceptable physiochemical and functional properties. Practical applications Potato is the third most cultivated crop in the world having balanced nutrients and good source of carbohydrates. It is mostly used at domestic scale and application of its processing products (potato powder) is limited especially in noodles (consumed all over the world). The addition of potato powder in noodles can be an alternative to the wheat flour (replacement of gluten protein). The results of present study can provide insights for making noodles especially the optimum level of potato powder is very important for the quality production of noodles.

Utilization of Kañawa (Chenopodium pallidicaule Aellen) Flour in Pasta Making

Kañawa (Chenopodium pallidicaule Aellen) is an Andean crop harvested in Bolivia and Perú. Because of the characteristics and properties of kañawa seed, its flour can be used to replace partially wheat flour in pasta to increase its nutritional value. The objective of this study was to investigate the production of fiber- and protein-enriched pasta made with wheat and kañawa blends. The effect of the substitution level of wheat by kañawa flour on pasta quality was evaluated taking into account the influence of kañawa composition on starch behavior and gluten network formation. Proximal composition, thermal behavior, and pasting properties of kañawa and wheat flours were determined. Pasta was made from wheat flour (control) replacing 10, 20, and 30% of wheat by kañawa flour from L1 and L2 ecotypes. Water absorption and cooking loss were increased showing the deleterious effect of kañawa flour on pasta quality, but the L1 ecotype showed better performance in cooking properties. Kañawa pasta firmness and chewiness decreased with the kañawa content increase; however, the L1 ecotype did not modify the firmness when 10 and 20% were included in pasta. Both kañawa flours improved the nutritional quality of pasta, increasing the dietary fiber content and protein quality.

Optimization of enzymes addition to improve whole wheat bread making quality by response surface methodology and optimization technique.

The functional ingredients in whole wheat flour, such as dietary fiber, vitamins, and minerals, have beneficial health effects. However, the excessive amount of dietary fiber in whole wheat flour inhibits gluten network formation and diminishes bread making qualities (BMQ). Adding appropriate amounts of enzymes, α-amylase (AM) and hemicellulase (HC), could be a solution to these problems. In this study, response surface methodology (RSM) created a response surface model and Solver (Excel add-in software) calculated the optimal amounts of the enzymes. Adding optimum concentrations of AM and HC drastically improved BMQ (gas retention of dough, specific loaf volume, and bread staling) of whole wheat flour dough and bread compared to whole wheat flour dough and bread without the enzymes. These results showed that combining RSM and Solver was an effective and reasonably easy method that determines optimal concentrations of enzymes to obtain the highest quality bread using whole wheat flour.

How to impact gluten protein network formation during wheat flour dough making

Gluten proteins strongly affect the structure and texture of various wheat flour-based baked goods. During dough making, gluten proteins are the main determinants of dough properties. Be it for research purposes or as a way of controlling dough properties in an industrial environment, different approaches have been taken to alter gluten network structure and, thus, functionality. In this brief review, we summarize these strategies, considering both processing-based interventions to gluten network formation and some additives commonly used to steer gluten protein functionality at the dough level.

Effect of β-Cyclodextrin on the Quality of Wheat Flour Dough and Prebaked Bread

This work investigated the effects of the addition of different concentrations (0–3.0 wt%) of β-cyclodextrin (β-CD) on the properties of wheat dough and prebaked bread. Dough tensile test results and scanning electron microscopy revealed that the addition of 0.5–1.5 wt% β-CD enhanced dough tensile strength and promoted gluten formation. The addition of 2.0–3.0 wt% β-CD, however, failed to improve gluten network formation. Fourier transform infrared spectroscopy showed that the α-helix-to-β-sheet ratios of dough samples increased as β-CD content increased. This result indicated that the protein secondary structure of the dough had changed. Fermentation rheometry illustrated that dough fermentation height, gas production volume, and gas-holding capacity increased with the addition of 0–1.5 wt% β-CD. Dough fermentation capacity decreased when the addition of β-CD exceeded 2.0 wt%. The effect of β-CD on the quality of prebaked frozen bread was also studied. The results of texture profile analysis indicated that the addition of 1.5 wt% β-CD could reduce bread hardness and increase bread crumb elasticity and resilience. The results of the C-cell test further demonstrated that the addition of 1.5 wt% β-CD could increase stomatal number and decrease pore number and pore wall thickness. These characteristics suggested that the addition of β-CD improved bread structure.

OPTIMIZATION OF NOODLE FORMULATION USING COMMERCIALIZED EMPTY FRUIT BUNCH PALM OIL CARBOXYLMETHYL CELLULOSE (CMC) AND FLOURS WITH DIFFERENT PROTEIN CONTENT

Carboxylmethyl cellulose (CMC) is extracted from empty fruit bunches of oil palm, which usually comes from industrial waste. The focus of this research is to recycle cellulose from the oil palm tree to produce a food product which is noodles. In this research, the noodles were produced from commercialized CMC (0 – 2%) by using 15 different formulations with different types of flour such as high protein flour, wheat flour and low protein flour which provides an added factor to improve texture. Proximate, physicochemical analysis and sensory test were conducted in order to determine the noodle’s nutrient content, colour, texture and acceptance level among the consumer panels. Based on the proximate analysis, high protein flour produced noodles that were similar to the positive control product which was a commercialized yellow noodles (Mi Kuning Rakyat). Fat, crude fiber, moisture and ash content did not show a significant difference among the formulation tested (p&gt;0.05) because the CMC used and different types of flour with different protein content used did not affect them. The compression test that was used to analyze texture in the physicochemical analysis revealed that Formulation 3 (F3), which was made up from high protein flour and 1% (w/w) CMC, had highest hardness with a mean score of 3.13 ± 0.06N and was significantly different (p&lt;0.05) in comparison with other 14 formulations. This indicates that the use of high protein flour helps in the formation of gluten network in the noodles while an optimum amount of CMC (1.0%) gives a good texture to the noodles. For hedonic test, Formulation 4 (F4), which was made up of 1.5% (w/w) CMC and high protein flour which contain 11.5-13.5% of protein, has a highest acceptance level for consumer due to a good taste and a better texture. Therefore, the integration of high fibrous flour from an empty fruit bunch of oil palm in the form of commerciallized CMC with flours with different protein content into noodle formulation can produce an improved noodles' quality that have higher acceptance level among the consumers.

Evaluation of dry heat treatment of soft wheat flour for the production of high ratio cakes

An accurate method to heat treat flour samples has been used to quantify the effects of heat treatment on flour functionality. A variety of analytical methods has been used such as oscillatory rheology, rheomixer, solvent retention capacity tests, and Rapid Visco Analysis (RVA) in water and in aqueous solutions of sucrose, lactic acid, and sodium carbonate. This work supports the hypothesis that heat treatment facilitates the swelling of starch granules at elevated temperature. Results furthermore indicated improved swelling ability and increased interactions of flour polymers (in particular arabinoxylans) of heat treated flour at ambient conditions. The significant denaturation of the proteins was indicated by a lack of gluten network formation after severe heat treatments as shown by rheomixer traces. Results of these analyses were used to develop a possible cake flour specification. A method was developed using response surfaces of heat treated flour samples in the RVA using i) water and ii) 50% sucrose solution. This can uniquely characterise the heat treatment a flour sample has received and to establish a cake flour specification. This approach might be useful for the characterisation of processed samples, rather than by baking cakes. Hence, it may no longer be needed to bake a cake after flour heat treatment to assess the suitability of the flour for high ratio cake production, but 2 types of RVA tests suffice.

Dissecting the Disulfide Linkage of the N-Terminal Domain of HMW 1Dx5 and Its Contributions to Dough Functionality

The N-terminal domain of HMW-GS 1Dx5 (1Dx5-N) contains three cysteine residues (Cys10, Cys25, Cys40), which are the basis of gluten network formation through disulfide bonds. Disulfide linkage in 1Dx5-N was dissected by site-directed mutagenesis and LC-MS/MS, and its contributions to structural and conformational stability of 1Dx5-N and dough functionality were investigated by circular dichroism, intrinsic fluorescence, surface hydrophobicity determination, size exclusion chromatography, nonreducing/reducing SDS-PAGE, atomic force microscopy, and farinographic analysis. Results showed that Cys10 and Cys40 of 1Dx5-N were the active sites for intermolecular linkage. Meanwhile, Cys40 also exhibited the ability to form intrachain disulfide linkage with Cys25. Moreover, Cys10 and Cys40 played a functionally important role in maintaining the structural and conformational stability and high surface hydrophobicity of the N-terminal domain of HMW-GS, which in turn facilitated the formation of HMW polymers and massive disulfide linkage of HMW-GS through hydrophobic interaction. Additionally, the 1Dx5-N mutants in which Cys were replaced by serine (Ser) presented different effects on dough functionality, while only the C25S mutant produced positive effects compared with wild type 1Dx5-N. Na2CO3-induced β-elimination of cystine might occur in glutenin without heating, which would make it much easier to reduce the nutritional quality of flour products by the cost of lysine. Therefore, these results give a deep understanding of the disulfide linkage of the N-terminal domain of HMW-GS and its functional importance, which will provide a practical guide to effectively generate a superior HMW-GS allele by artificial mutagenesis.

Recombinant Wheat Endoplasmic Reticulum Oxidoreductin 1 Improved Wheat Dough Properties and Bread Quality.

Recombinant wheat endoplasmic reticulum oxidoreductin 1 (wEro1) with considerable ability was expressed in Escherichia coli. The functional roles of wEro1 in flour processing quality were investigated by farinographic, rheological, texture profile analysis, electrophoresis, size exclusion chromatography, scanning electron microscopy, and Fourier transform infrared spectroscopy. wEro1 exhibited an obvious oxidation activity of sulfhydryl groups in small molecule and protein. Addition of wEro1 could strengthen the processing quality of dough, indicated by the improved mixing characteristics, viscoelastic properties, and bread qualities. These improvement effects of wEro1 could be attributed to the formation of macromolecular gluten polymers and massive gluten networks by disulfide cross-linking. Additionally, the increased β-turn structure further demonstrated the enhancement of dough strength. Moreover, the amount of peroxide in dough was improved significantly from 2.36 to 2.82 μmol/g of flour with 0.15% wEro1 treatment. Therefore, the results suggested that wEro1 is a promising novel flour improver.