Wheat Flour Dough Rheology Research Articles

The relationship between large deformation rheology of wheat flour dough with protein quantity and aggregate stretching degree of milling streams flour based on regression analysis

The relationship between large deformation rheology of wheat flour dough with protein quantity and aggregate stretching degree of milling streams flour based on regression analysis

Empirical rheology of wheat flour doughs with pea, soybean and whey protein isolates

The use of different protein sources in cereal products does not only aim to enrich them with proteins, but also to improve their protein quality, especially concerning the lysine content, the limiting amino acid in wheat flour. As an alternative to enrichment, protein isolates become viable because they provide protein content and quality. However, that the addition of protein sources to wheat flour greatly affects its rheological properties. Thus, the objective of this study was to evaluate the empirical rheology of wheat flour doughs substituted by pea (PPI), soybean (SPI), and whey (WPI) protein isolates, comparing the behavior of these three sources in order to predict the best application. Of all the isolates, PPI seems to have interfered less in the rheological profile of pure flour. WPI caused major changes, while SPI remained intermediate, but closer to PPI. Concentrations of PPI and SPI up to 10% and WPI up to 5% did not greatly modify the viscoelastic profile of the dough, which would allow the use of these mixtures in the production of breads, while higher concentrations would be more suitable for the manufacture of molded biscuits, in which the formation of a protein network is not necessary.

Impact of Different Amaranth Particle Sizes Addition Level on Wheat Flour Dough Rheology and Bread Features.

The objective of this investigation was to evaluate the effects generated by amaranth flour (AF)—of different particle sizes (PS) added to white wheat flour from 0% to 20%—on the proximate composition, dough rheological behavior, and bread technological parameters. The reduction of particle size led to an increased hydration capacity of the wheat–amaranth composite flour, while bulk density decreased. Increasing the amount of AF and decreasing the PS led to a significant increase in protein, lipids, and ash contents, while the moisture and carbohydrates of the composite flour decreased. Increasing AF addition led to an increase in dough tenacity and a decrease in dough extensibility, while the PS had an irregular trend. The large particle size, at 15% and 20% levels of AF in wheat flour, increased significantly (p < 0.001) the dough tenacity and hardness, bread firmness, but decreased bread volume, porosity, and elasticity, while medium and small particles at 5–15% addition levels improved porosity and elasticity of the composite bread. Significant correlations (p < 0.05) were found between proximate composition, dough rheological characteristics, and bread quality for the wheat–amaranth composite flours. The results of this study are an important basis for the development of innovative wheat–amaranth bread recipes.

AMARANTH INFLUENCE ON WHEAT FLOUR DOUGH RHEOLOGY: OPTIMAL PARTICLE SIZE AND AMOUNT OF FLOUR REPLACEMENT

Knowledge of various amaranth flour (AF) particle sizes influence added in different amounts in refined wheat flour (WF) seems necessary to properly design systems with expected rheological properties. The study aimed to assess the effects of factors, particle size and level of AF added in WF on Falling number index (FN) and dough rheological properties described by Mixolab in a systematic investigation based on design of experiment. The level of AF added in WF significantly influenced the FN values in the linear and quadratic terms (p &lt; 0.05), revealing a decrease with the level increase. Particle size played a significant role in increasing water absorption in linear and quadratic terms (p &lt; 0.05), whereas only the linear term has a significant effect (p &lt; 0.005) on dough development time and stability. Particle size increase and the interaction between particle size and AF significantly increased torques C2 and C3. AF level increase in WF significantly decreased the torques C4 and C5. The optimization results highlighted that the most suitable combination would be the composite flour with 9.74% AF of 280 μm particle size incorporated in WF. The proposed approach and the information resulted can be relevant for industrial applications, helping to develop products with amaranth with optimum rheological properties, in order to scale-up the production.

Impact of Dairy Ingredients on Wheat Flour Dough Rheology and Bread Properties

The incorporation of dairy ingredients, such as milk or acid whey in bread, is advantageous considering their functional properties and the positive effects on consumers’ health. The introduction of an ingredient in bread making process requires the evaluation of dough behavior and final product quality. Thus, the influence of water replacement by milk or acid whey on the characteristics of wheat flour dough and bread was studied. Dynamic rheological measurements were performed in order to evaluate the viscoelastic properties of dough. Compared to the control, an increase of the elastic character of dough for samples with milk and a decrease for those with acid whey was observed. The resistance to deformation decreased when water was substituted with more than 25% milk and increased for samples with up to 25% acid whey. Higher maximum gelatinization temperatures were obtained when water was substituted by milk or acid whey. Bread crumb presented higher firmness, lower volume and porosity for samples with dairy ingredients compared to the control, therefore, replacement levels lower than 25% were recommended in order to minimize this negative effect. Bread elasticity, chewiness, resilience, pores density and size were improved at replacement levels lower than 25%, while for the sensory characteristics of the specialty bread, high scores were obtained. These results can be helpful for processors, in order to develop and optimize bread with dairy ingredients.

Rheology Methods as a Tool to Study the Impact of Whey Powder on the Dough and Breadmaking Performance of Wheat Flour

Considering the nutritional value, whey is an excellent ingredient for the development of food products, in line with the concept of a circular economy for the reuse of industry by-products. The main objective of this work was to evaluate the impact of the whey addition on the rheology of wheat flour dough and breadmaking performance, using both empirical and fundamental methods. Different levels of commercial whey powder (0%, 12%, 16% and 20% w/w) were tested in a bread formulation previously optimized. Dough mixing tests were performed using Micro-doughLab and Consistograph equipment, to determine the water absorptions of different formulations and evaluate empirical rheology parameters related to mixing tolerances. Biaxial extension was applied by the Alveograph to simulate fermentation during the baking process. Fermented doughs were characterized in a Texturometer using penetration and extensibility tests, and by small amplitude oscillatory shear (SAOS) measurements, a fundamental rheology method, in a Rheometer applying frequency sweeps. Loaf volume and firmness were used to study the breadmaking quality. Despite a negative impact on the empirical rheology parameters of the dough and poorer baking results, the use of this by-product should be considered for nutritional and sustainability reasons. In addition, significant correlations (r2 &gt; 0.60) between the dough rheology parameters obtained from the empirical measurements were established. Changes in the gluten structure were not accurately detected by the SAOS measurements and Texture Profile Analysis of the doughs, and a correlation between fundamental and empirical measurements was not found. Consistograph or Micro-doughLab devices can be used to estimate bread firmness. Extensional tests in the Texturometer, using SMS/Kieffer Dough and Gluten Extensibility Rig, may predict loaf volume.

Grape seeds effect on refined wheat flour dough rheology: optimal amount and particle size

Grape seeds effect on refined wheat flour dough rheology: optimal amount and particle size

Isolation and characterization of arabinoxylans from wheat bran and study of their contribution to wheat flour dough rheology

The study was aimed to evaluate the yield and sugar composition of water-extractable (WE) and alkali extractable (AE) Hemi-A, Hemi-B and oligosaccharides (Oligo) fractions isolated from bran of four wheat varieties and their relationship with dough rheology. Wheat bran from all varieties were rich in protein content (12.45–16.97%). The yield of WE-Hemi-A, WE-Hemi-B and WE-Oligo were lower than the yield of AE-Hemi-A, AE-Hemi-B and AE-Oligo, for all varieties. Sugar composition of fractions determined by high-performance anion exchange chromatography with pulsed amperometric detector (HPAEC-PAD), showed sugars: rhamnose, galactose, glucose, galacturonic acid and glucuronic acid, in addition to the typical arabinoxylan containing arabinose and xylose are present in all wheat bran varieties. HD-3086 and HD-2947 wheat varieties which yielded a viscoelastic dough with high G' and G" values (indicative of good dough-making characteristics), had a higher percent of AE-Hemi-B and both WE-Oligo and AE-Oligo than C-306 and HS-490 wheat varieties.

Impact of tempeh flour on the rheology of wheat flour dough and bread staling

Solid-state fermentation of soybeans by Rhizopus oligosporus RT-3 and Actinomucor elegans DCY-1 can be used as a natural enzyme pool for the improvement of dough and bread quality. Rheological analysis indicated that addition of tempeh flour (TF) increased G′ and G’’ moduli of dough. TF bread showed the largest specific volume (4.32 mL/g) and lowest hardness (113.64 g) on the first day. Bread substituted with TF exhibited less moisture loss in crumb (1.2 g/100 g) during the seven days storage. Molecular mobility and starch retrogradation of bread was measured by using low-field nuclear magnetic resonance (LF-NMR). Three different proton fractions, peaking at ∼0.16–0.24 ms (population A), ∼2.33–5.10 ms (population B) and ∼41.93–65.79 ms (population C), were detected by LF-NMR. Smaller changes in proton distributions (population A and B) of TF bread indicated that addition of tempeh flour hindered the shift of protons and the formation of amylopectin crystals during storage. TF bread was found to be sensorially acceptable and the highest scores for texture, aroma and volume were obtained. These results indicate that TF has great potential use for the improvement of bread quality and control of bread staling.

Impact of Chlorella vulgaris on the rheology of wheat flour dough and bread texture

Modern foods lead to healthier, cheaper and more convenient products to increasingly demanding consumers. Microalgae are an enormous biological resource, representing one of the most promising sources for new products and applications and can be used to enhance the nutritional and technological value of food products. The enrichment of bread with microalgae biomass is a great challenge resulting from its impact on the development of the gluten structure. The addition of Chlorella vulgaris in a wheat flour dough was studied, to evaluate its influence on the dough rheology and bread texture. Microalgae contents from 1.0 to 5.0 g per 100 g of wheat flour were tested and it was observed that up to 3.0 g of microalgae biomass addition, a positive impact on dough rheology and viscoelastic characteristics, with strengthening of the gluten network, was observed. For higher microalgae content, a negative effect on dough rheology, bread texture and flavor was noticed and an acceleration on bread aging was relevant. No impact on the kinetics of yeast fermentation, neither on the time required for fermentation, was induced by the biomass addition.

The Impact of Water Content and Mixing Time on the Linear and Non-Linear Rheology of Wheat Flour Dough

The viscoelastic properties of wheat flour dough are known to be very sensitive to small changes in water content and mixing time. In this study the simple scaling law originally proposed by Hibberd (1970) [Rheol. Acta 9, 497-500] to capture the water dependency of the dynamic moduli in small amplitude oscillatory shear, was also applied to creep-recovery shear tests and extensional tests. The scaling law turns out to be valid not only in the linear region, but to a certain extent also in the non-linear region. At sufficiently high water levels, a ‘free’ water phase exists in dough, which attenuates the starch-starch and gluten-starch interactions. Dough characterisation after different mixing times shows that overmixing may cause a disaggregation or even depolymerisation of the gluten network. The network breakdown, as well as the subsequent (partial) recovery, are clearly reflected in the value of the strain-hardening index, for which a maximum is reached at a mixing time close to the optimum as determined with the Mixograph. Finally, the gluten proteins turn out to be much less susceptible to overmixing in an oxygen-lean environment, which demonstrates the significant role of oxygen in the degradation process.

The Interplay Between the Main Flour Constituents in the Rheological Behaviour of Wheat Flour Dough

There is still considerable debate in the literature about the respective roles of starch and gluten in both the linear and non-linear rheology of wheat flour dough. Hence, to elucidate the individual contributions of gluten and starch to the overall dough behaviour, the rheological properties of dough and mixtures of different gluten-starch ratios were studied systematically in shear and extension, by means of an adequate rheological toolbox consisting of linear small amplitude oscillatory shear tests and non-linear tests such as creep-recovery in shear and uniaxial extension. The starch component plays a pivotal role in linear dough rheology. With increasing starch content, the linearity limit observed in oscillatory shear tests decreases as a power-law function. Starch also clearly affects the extensional viscosity at small strains. Consequently, in the linear region differences between different gluten systems may become obscured by the presence of starch. As breadmaking qualities are known to be intrinsically linked to the gluten network, it is imperative to probe the non-linear behaviour of dough in order to expose differences in flour quality. The quality differences between a strong and a weak flour type were revealed most clearly in the value of the strain-hardening index in uniaxial extension and the total recovery compliance in non-linear creep-recovery tests. Notwithstanding its earlier successful application to pure gluten gels, the accuracy of the critical gel model in predicting the linear rheological properties of dough was found to be limited, due to dough having a small linearity limit and a finite longest relaxation time.

Effect of Condensed Tannin Profile on Wheat Flour Dough Rheology.

Proanthocyanidins (PA) cross-link proteins and could expand wheat gluten functionality; however, how the PA MW or gluten profile affect these interactions is unknown. Effect of PA MW profile (sorghum versus grape seed PA) on dough rheology of high versus low insoluble polymeric protein (IPP) wheat flour was evaluated using mixograph, large (TA.XT2i) and small (HAAKE Rheostress 6000) deformation rheometry. Sorghum PA (93% polymeric) more effectively (p < 0.05) strengthened both glutens than grape seed PA (45% polymeric), without reducing gluten extensibility. These effects were higher in low IPP (weak gluten) flour, e.g., sorghum PA doubled IPP, increased mix time by 75%, dough elasticity by 82%, and peak angle by 17° versus control. Grape seed PA increased IPP by 75% and elasticity by 36%, but reduced peak angle by 15°, indicating reduced mixing tolerance. Sorghum PA, but not grape seed PA, increased (p < 0.05) all above parameters in high IPP dough. Polymeric PA more effectively strengthened gluten than oligomeric PA, likely via more efficient protein cross-linking to overcome strong antioxidant effect of PA. High MW PA may be useful natural gluten strengtheners for diverse applications.

Effect of incorporating potato dietary fibre to wheat dough on the quality of baked rolls

Abstract The effect of incorporation of commercial potato dietary fibre at different levels (1, 3, 5 and 10 %) on wheat flour dough rheology, qualitative and sensory properties of baked rolls was evaluated. Potato dietary fibre exhibits good hydration properties (water holding, water retention and swelling capacity). Its addition into wheat dough increased water absorption, prolonged dough stability and dough development time. Also, it was found that the potato fibre incorporation to wheat rolls negatively affects both volume and specific volume, and cambering of baked rolls. Sensory evaluation showed that rolls with the addition of potato dietary fibre at levels 1 and 3 % had high overall acceptability.

Effect of β-D-glucan concentrate and water addition on extensional rheology of wheat flour dough

Extensional properties of wheat flour and composite wheat flour/β-glucan concentrate (BGC) doughs were studied as function of water content (58–70 mL/100 g flour) and β-D-glucan concentrate (2.5–10 g/100 g). Water absorption increased linearly with increasing BGC level in the composite dough whereas the dough extensibility reduced significantly at similar condition. The peak pressure value of the inflated dough increased and the bubble height decreased with increasing BGC concentration, whereas a reverse trend was observed during plasticization of dough by water addition irrespective of BGC concentration. Henky strain of dough at break point decreased with incorporation of BGC and the value ranged between 0.98 and 1.71. The strain hardening index was calculated from stress–Henky strain data which obtained directly from biaxial measurement and the value increased with BGC incorporation compared to wheat flour dough. A linear relationship was found between extensibility and Henky strain of dough at break point that could be used to convert data from empirical to fundamental rheological measurement or vice-versa. All those information would be helpful to design and quality control of β-D-glucan enriched food products.

Effect of waxy flour blends on dough rheology and bread quality

Summary Although much research has been conducted on wheat flour dough rheology, the principal focus has been the role of the protein fraction. Starch is the main component of flour and plays a key role in dough dynamic properties, particularly during heating. This study assesses the effect of two different waxy flours, a durum and a bread wheat, and their blends with commercial bakers' flour on dough rheology during heating with a concurrent investigation into baking performance. Both waxy flour blends produced similar effects on dough rheological behaviour despite differences in protein content, acting to delay gelatinisation and reduce storage modulus. The main effects in bread were to increase loaf expansion during baking and reduce loaf firmness. It is postulated these effects are largely water mediated, with the higher swelling ability of the waxy starch granules reducing overall water availability and driving complete gelatinisation to higher temperatures.

What Has Low-Intensity Ultrasound Informed Us about Wheat Flour Dough Rheology?

The role of rheology in understanding the process behavior of dough and its predictive capacity with respect to breadmaking quality is of long-standing interest to cereal scientists. Over the past 12 years, we have undertaken a comprehensive examination of the rheology of wheat flour doughs using low-intensity ultrasound. Propagating shear waves at ultrasonic frequencies in conjunction with small-strain shear rheometry allowed us to show how a very broad distribution of relaxation times is necessary to define the complex shear modulus of wheat flour dough. When propagating longitudinal ultrasonic waves, three distinct regions are seen in the ultrasonic spectrum arising from the presence of bubbles in the dough. At low frequencies, where the properties of the bubbles–dough matrix “composite” are probed, the rheology of air-mixed doughs contrasts markedly with that of doughs mixed under vacuum. Therefore, all dough rheology is affected by the bubbles within the dough.

Nonlinear, time-dependent shear flow behaviour, and shear-induced effects in wheat flour dough rheology

Retardation test, step-shear rate experiments, low-amplitude and large-amplitude dynamic measurements have been combined to study the nonlinear and time-dependent viscosity of dough and shear-induced effects of flow on dough structure. Despite large quantitative differences in linear viscoelastic constants, doughs from different flours or with different water contents display the same type of flow behaviour. Shear-induced structural changes cause flow to shift from a high viscosity steady-state regime to a low viscosity one. The process, irreversible, is responsible for the time-dependent character of dough viscosity and seems to be controlled by the mechanical energy absorbed. Nevertheless, the two steady-state viscosities follow the same shear-thinning flow curve, fitted by a Cross equation with an exponent close to 1; the Newtonian plateau is approached at very low shear rate values. Viscosity data obtained on different doughs yield a unique flow master curve in reduced coordinates. Shear-induced structural changes cause also the linear viscoelastic plateau modulus of dough to decrease; this progressive weakening of the network structure is irreversible and seems governed by the accumulated strain. These characteristics of dough rheology are discussed with reference to the behaviour of concentrated suspensions.

BIAXIAL EXTENSION OF WHEAT FLOUR DOUGHS: LUBRICATED SQUEEZING FLOW AND STRESS RELAXATION PROPERTIES

ABSTRACT Biaxial extension in lubricated squeezing flow (LSF) was first developed for molten polymers and transferred to the study of wheat flour dough (1986). Depending on geometry, LSF is performed at constant surface or at constant volume. Most of the measurements have been carried out with a mechanical testing machine at constant crosshead speed and constant surface. An empirical power law equation relates stress and strain rate at constant strain and, at a given strain rate, there is an approximate exponential stress–strain relationship from which a parameter named “strain hardening” is derived and tentatively related to resistance of dough membranes against premature rupture. This exponential relationship does not seem to hold in other experimental conditions, particularly at constant volume. Stress relaxation following lubricated compression might also allow the study of dough viscoelastic properties. The role of unsteady regime, testing conditions and dough compressibility is finally discussed. PRACTICAL APPLICATIONSExtensional flow properties of polymers have long been recognized as important for understanding their processing behaviors and the experimental measurement of these properties has been the subject of many studies. The relevance of biaxial extension properties to dough behavior in baking technology was at the origin of the Alveograph developed by Chopin more then 80 years ago. A third method, lubricated squeezing flow (LSF), was firstdeveloped in 1981 for studying the biaxial extension viscosity of molten polymers in creep. It is based on the uniaxial compression of a cylindrical sample between two parallel surfaces. Due to its simplicity, versatility and availability, LSF has found several empirical applications in food, particularly in wheat flour dough rheology.

Linear to Non-linear Rheology of Wheat Flour Dough

Abstract We provide an overview of transient extensional rheometry techniques for wheat flour doughs in which the deformation and material response is well defined. The behavior of a range of model doughs was explored with a Filament Stretching Extensional Rheometer (FISER). The measurements were also compared to data obtained with a new wind- up extensional rheometer; the SER universal testing platform. A simple empirical constitutive equation, which allows characterization of the experimental results with a small number of parameters, is presented to describe the resulting measurements. To characterize the relaxation modulus of the doughs, small amplitude shear tests were performed on samples that have been shear-mixed in a mixograph for varying lengths of time. The linear viscoelastic properties were found to exhibit a broad power-law dependence on the imposed oscillatory frequency that is very reminiscent of that exhibited by a critical gel. The critical gel model of Winter and Chambon [1, 2] was used as the basis for constructing a non-linear constitutive equation for the material stress by combining the relaxation modulus for the critical gel with a Lodge rubber-like liquid form for the kinematics. Transient uniaxial extensional data recorded from the FISER and SER instruments were then compared to the predictions of the constitutive equation. The model captures the initial power- law response and subsequent strain-hardening; however additional physics is required to describe the rheological phenomena at very large Hencky strains, including finite extensibility effects and filament rupture in extensional flows.