Dynamic Frequency Sweep Research Articles

Influence of refreshment varying flour and water on sourdough viscoelasticity and textural properties of bread

AbstractBackground and ObjectiveSourdough involves spontaneous fermentation by wild yeast and lactic acid bacteria. This study investigates the effects of varying water and flour proportions on sourdough and formulated dough viscoelasticity and bread textural properties after a 7‐day refreshment period. Daily, 20% or 30% water and 30% or 40% flour were added using refined or 20% fiber‐enriched flour. The pH and titratable acidity of the sourdough were measured, while dynamic frequency sweep tests were conducted to assess the viscoelastic properties of both sourdough and formulated dough. Additionally, the textural parameters of bread were evaluated.FindingsThe pH of the sourdough was lower when refined flour was used, but total titratable acidity analyses indicated higher acidity with 20% fiber‐enriched flour, demonstrating greater efficacy in this study. In the sourdough, G″ exceeded G′, indicating a more pronounced viscous behavior. Conversely, in the formulated dough, G′ was higher, suggesting greater elasticity. The treatment involving 20% water and 40% refined flour resulted in higher G′ and G″ values in both the sourdough and formulated dough. Meanwhile, the combination of 20% water and 30% refined flour produced bread with the highest specific volume and springiness, along with the lowest firmness, chewiness, and gumminess.ConclusionThe best bread was achieved with 20% water and 30% refined flour for refreshment.Significance and NoveltyThis study provides insights for optimizing sourdough formulations, benefiting artisanal and industrial bread‐making.

Changes in rheology and components during the processing of Chinese traditional handmade hollow dried noodle

The study of the changes in rheological properties and components during the processing of Chinese traditional handmade hollow dried noodle (HHDN) is essential to explaining the excellent quality of HHDN. The dynamic oscillation frequency sweep, stress relaxation, and uniaxial extension characteristics of the dough after kneading, stretching, and resting were investigated at six sampling points during the processing of HHDN. The result showed that stretching led to an increase in G' and G0, and a significant decrease (P < 0.05) in extensibility from 131.02 mm to 57.99 mm. Confocal laser scanning microscopy (CLSM) was used to observe the microstructure of the gluten network, which was destroyed during stretching and restored during resting. Studies of changes in components showed that the stretching process resulted in a decrease in GMP content from 3.24 (g/100 g) to 3.18 (g/100 g), and the resting process resulted in β-sheets decreasing significantly (P < 0.05). The degree of starch pasting increased significantly (P < 0.05) after stretching. The results of the correlation analysis showed that components changes were highly correlated with the rheological properties during the processing of HHDN.

Effects of Ultrasonic Power on the Structure and Rheological Properties of Skin Collagen from Albacore (Thunnus alalunga).

The effects of ultrasonic power (0, 150, 300, 450, and 600 W) on the extraction yield and the structure and rheological properties of pepsin-soluble collagen (PSC) from albacore skin were investigated. Compared with the conventional pepsin extraction method, ultrasonic treatment (UPSC) significantly increased the extraction yield of collagen from albacore skin, with a maximum increase of 8.56%. The sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis revealed that peptides of low molecular weight were produced when the ultrasonic power exceeded 300 W. Meanwhile, secondary structure, tertiary structure, and X-ray diffraction analyses showed that the original triple helix structure of collagen was intact after the ultrasonic treatment. The collagen solutions extracted under different ultrasonic powers had significant effects on the dynamic frequency sweep, but a steady shear test suggested that the collagen extracted at 150 W had the best viscosity. These results indicate that an ultrasonic power between 150 and 300 W can improve not only the extraction yield of natural collagen, but also the rheological properties of the collagen solution without compromising the triple helix structure.

Rheological properties of graphene oxide/polyamide 6 composites

AbstractIn this work, graphene oxide (GO)/polyamide 6 (PA6) nanocomposites with different graphene content (0.03–0.5 wt%) were prepared via in situ polymerization of GO and ε‐caprolactam. The linear and nonlinear rheological properties and thixotropy of GO/PA6 nanocomposites are investigated using steady state, dynamic, and transient rheological method with a Haake plate rotary rheometer. Cox/Merz rules and Cross model were used to fit the shear rate sweep and dynamic frequency sweep data, and a wider range(10−2–104 s−1) of flow curve was obtained. The results show the PA6 and GO/PA6 melts are shear thinning fluid without yield stress, and have thixotropy.Highlights Dynamic, steady, and transient rheological tests were performed. Cox/Merz rules and Cross model were used to fit the data. A wider range(10−2–104 s−1) of flow curve was obtained.

Rheological properties of cross-linked inulin solutions as a function of cross-linker concentration and temperature

The purpose of this study is to determine the rheological properties of cross-linked inulin solutions in two different polymerization degrees (native and degree of polymerization of >23%). Thus, the effect of cross-linking, a new approach applied to support a specific property (stabilization) of inulin, which has many benefits, has been demonstrated. Sodium hexametaphosphate was used as a cross-linking agent at three different ratios (0.375%, 0.500%, and 0.750%). The cross-linked inulin solutions were lyophilized, and the lyophilized mixture was then reconstituted at 25 °C and 45 °C to obtain cross-linked inulin solutions with 1% and 5% (w/v) concentrations. The control samples (native and with a high degree of polymerization) were treated similarly without a cross-linking agent. The samples were subjected to a dynamic frequency sweep test in the range of 0.01–10 Hz as well as shear viscosity measurements at 1–500/s shear rates for the determination of rheological properties. The thixotropic curves were analyzed as the shear rate increased from 0.1/s to 300/s in the first 120 s (up curve), and then decreased to the same point in the subsequent 120 s. Results indicated that cross-linking increased inulin solution viscosity, particularly at 5% concentration, and solubility. Solutions with 5% inulin containing 0.750% and 0.375% cross-linker yielded the highest viscosities at 45 °C and 25 °C, respectively. Samples with 5% inulin concentration exhibited solid-like behavior in the oscillation test. Thixotropic curves revealed antithixotropy at low shear rates and thixotropy at high shear rates. The study demonstrated the impact of cross-linking on inulin stabilization, providing insights for future applications. Results indicated that cross-linking increased inulin solution viscosity, particularly at 5% concentration, and solubility. Solutions with 5% inulin containing 0.750% and 0.375% cross-linker yielded the highest viscosities at 45 °C and 25 °C, respectively. Samples with 5% inulin concentration exhibited solid-like behavior in the oscillation test. Thixotropic curves revealed antithixotropy at low shear rates and thixotropy at high shear rates. The study demonstrated the impact of cross-linking on inulin stabilization, providing insights for future applications.

Evaluation of the biosynthesis, structural and rheological characterization of succinoglycan obtained from a formulation composed of whole and deproteinized whey

In this study, succinoglycan was produced from whey and its rheological and structural characteristics were elucidated. Eight culture media were prepared with different ions for bioconversion of whey into succinoglycan. The formulation composed of deproteinized whey, monobasic potassium phosphate and magnesium sulfate allowed the production of 13.7 ± 0.43 g/L of succinoglycan. The apparent molar mass of succinoglycan was estimated to be 9.033 × 105 g/mol and the polydispersity index was 1.044, representing the homogeneity of the sample. Monosaccharide composition of glucose and galactose for the succinoglycan produced was 6.6:1.0. The 1H RMN analysis revealed the non-saccharide substituent content of 1.2%, 3.0% and 8.1% for acetyl, succinate and pyruvate, respectively. The rheological results showed that the apparent viscosity of the succinoglycan solutions was directly proportional to the concentration, and the solution showed pseudoplastic behavior. Dynamic frequency sweep tests identified that a concentration of 2.0% of succinoglycan is required for formation of the gel system. Temperature influenced the viscoelastic behavior of succinoglycan and revealed the melting point and reversibility of the gel. Whey was shown to be a promising carbon source for the production of succinoglycan with thickening potential and viscosity modifier.

Oxidized yeast β-glucan: Rheological behaviors and the formation of entanglement network at different oxidation degree

This work investigated the rheological properties of oxidized yeast β-glucans (OYG) with three different oxidation degrees (15.2%, 47.3% and 71.2%). Firstly, the intrinsic viscosities of OYG2 and OYG3 calculated by Huggins and Kraemer equations were 104 and 214 mL/g, respectively. Steady-state shear test showed that the OYG solutions exhibited shear-thinning behavior of pseudoplastic non-Newtonian fluid when concentration (c) was greater than 5 mg/mL and OYG1 had the highest apparent viscosity. By fitting viscosity data to the Cross model, the critical overlap concentration (c*) were determined to be 4.69, 3.79 and 2.25 mg/mL for OYG1, OYG2 and OYG3, respectively. From the results of dynamic frequency sweep test, the storage modulus (G′) and the loss modulus (G″) were greatly dependent on frequency and concentration, and OYG solutions represented the feature of structural fluid, an entanglement network at c ≥ 5 mg/mL. Micro-rheological test revealed that the OYG1 solutions were dominated by viscoelasticity at c ≥ 13 mg/mL and the Fluidity Index (FI) decreased with increasing concentration, indicating the increase in elasticity and viscosity. Meanwhile, as the concentration increased from 13 to 20 mg/L, shorter time and lower temperature were required for OYG1 to form a gel, as indicated as they decreased from 53′21″ and 78.60 °C to 41′34″ and 67.40 °C, respectively. Results of temperature ramp test illustrated a thermo-irreversible characteristic of OYG1/water system. The findings suggest that OYGs can be potentially employed in food or cosmetic products for various applications as thickener, stabilizer and so on.

Prediction of the viscoelastic properties of a cetyl pyridinium chloride/sodium salicylate micellar solution: (I) characterization

The characterization capability of constitutive equation on the viscoelastic property of micellar solution was checked in this study. A modified viscoelastic model was employed here to express the viscoelastic properties of a cetyl pyridinium chloride/sodium salicylate (CPyCl/NaSal) wormlike micellar solution at 22 °C that was experimentally obtained in 2010. The relaxation spectrum of the CPyCl/NaSal solution was fitted using the dynamic frequency sweep, the parameter in the Papanastasiou-Scriven-Macosko damping function was obtained using stress relaxation in step strain, the structuralized parameter f in the model was obtained using the steady shear stress, and the parameter ζ was obtained using the stress growth in the shear startup experiment. Afterwards, the first normal stress difference of the solution in the steady shear experiment was predicted. The study clearly shows improvement in the calculated viscoelastic properties of the micellar solution compared with those obtained by the Vasquez-Cook-Mckinley model, such as steady shear stress.

Development of single‐polypropylene composites interleaved with MWCNT‐doped melt‐blown fine fiber mats

AbstractIn this article, we demonstrate fabricating polypropylene (PP)/multiwalled carbon nanotube (MWCNT) nanocomposite fiber veils and use them as interleaves in single‐polymer composites (SPCs) to enhance their thermal and mechanical properties. With this regard, we produced a hierarchical composite structure made of a film, a woven fabric and a fine fiber mat made of the same polymer. The nanocomposite fiber mats were generated by melt‐blowing. Results implied that incorporating MWCNT increased the viscosity of the melt blowing grade PP resin. Increasing MWCNT content increased the average fiber diameter and pore size by 2.1‐fold and 2.5‐fold, respectively. Incorporating MWCNT enhanced the melt‐blown (MB) fiber mat's specific strength by 78% and improved the thermal stability. We generated multiscale SPCs by film‐stacking, for which we applied a PP film as a matrix, a PP‐woven fabric as the primary reinforcement, and the MB fiber mats as interleaves. The SPC's tensile modulus was improved by 37% by the interleaving. Our findings implied that the MWCNT‐doped PP fiber mat interleaving provides a robust interfacial adhesion and higher damage tolerance under tensile load. Master curves were constructed from dynamic mechanical analysis frequency sweep tests based on the time–temperature superposition principle. The storage modulus increased by 33%, while the tanδ decreased around 10% with PP/MWCNT fiber mat interleaving. The developed multiscale SPC with MWCNT fiber mat interleaving veils may be easily integrated into engineering composite applications due to its cost‐efficiency, fair recycling, straightforward processing, enhanced stiffness, and interfacial adhesion.

Rheological behaviour and antibacterial activities of MWCNTs/ lyotropic liquid crystals based nanocolloids

ABSTRACT Nanocolloids are prepared via doping of 0.015 mg and 0.030 mg multiwalled carbon nanotubes (MWCNTs) in the lyotropic phases of cetylpyridinium chloride (CPC)/glycerol (2:98, 5:95, 10:90 and 20:80 wt%/wt%). Nanocolloids are characterised by polarising optical microscopy (POM) for structural confirmations. No phase change has been observed in any sample with MWCNTs doping concentrations. Non-doped lyotropic phases and nanocolloids are studied for static and dynamic rheology, frequency sweep and thixotropic behaviour. Shear rheology infers about the shear thinning to Newtonian till 10:90 CPC/glycerol concentration and shear thickening to Newtonian for 20:80 wt%:wt% system. The studied systems follow the nematodynamic concept. The frequency sweep test infers that lyotropic mesophases and nanocolloids exhibit viscoelastic behaviour. Further, the thixotropic measurements infer the weak gel nature of mesophases and nanocolloids. Lyotropic phases and nanocolloids show strong inhibition properties against the gram-negative Escherichia Coli (E. Coli.) bacteria. Lyotropic phases and nanocolloids can be used in microbial and lubrication applications. The unique antibacterial properties of these systems make them suitable for use in medical and pharmaceutical devices to prevent the spread of infection.

Quantitative insights into rheology of self-crosslinking dialdehyde carboxymethyl cellulose/collagen solution: A comprehensive experimental and modelling investigation

Rheological behaviors (fluid type, thixotropy, viscoelasticity and deformation resistance) of self-crosslinking dialdehyde carboxymethyl cellulose (DCMC)/collagen solutions were comprehensively investigated and quantitatively modelled. The formation of self-crosslinking bonds gave rise to the enhancement of entanglements among collagen molecules and aggregates, resulting in the improvement of collagen solution's mechanical properties. The collagen solution was typical pseudoplastic fluid with shear-thinning behavior, and DCMC did not alter its flow behavior; therefore, the flow curves for all samples could be well simulated by Ostwald-de Waele and Carreau models. However, the viscosity and pseudoplasticity increased, and the effect of DCMC became more pronounced at higher DCMC/collagen ratios. Similar upward variation was observable for thixotropy, detected by the increased area of hysteresis loops from 20.947 to 219.978 Watts/m3. Additionally, the negative values of apparent yield stress and flow index below 1 from Herschel–Bulkley model confirmed that the DCMC/collagen solutions remained pseudoplasticity without yield stress. The viscoelasticity was examined based on dynamic frequency sweep and creep–recovery measurement and then simulated using Leonov model, Burger model and a semi-empirical model, respectively. The increases in elastic moduli and proportion of recoverable compliance reflected the self-crosslinking DCMC/collagen solutions had stronger elasticity and exhibited more resistance to deformation than the native collagen solution. Nevertheless, the more complicated structures of the DCMC/collagen solutions required more time to recover after removing external force. These data can be directly applied to the utilization of DCMC/collagen solutions, whilst also provide a basis for the prediction of printability or spinnability of collagen-based materials.

Effect of Sugars on Gelation Kinetics of Gelatin Gels

We investigate the rheological behavior of aqueous solutions containing animal gelatin, sugars and polyols. The aim is to study how the gelation kinetics, transition temperatures and gel strengths of an aqueous gelatin solution can be affected by the progressive addition of co-solutes. Aqueous solutions with a fixed mass percentage of gelatin of 6.8 wt% were prepared at various concentrations of sugars and polyols. Through Dynamic Temperature Ramp tests, performed at various ramp rates, and Dynamic Time Sweep and Dynamic Frequency Sweep tests, carried out at different temperatures, it was possible both to evaluate the transition temperatures and to monitor the gelation kinetics of the samples. It was found that the contribution of co-solutes positively affects both the gelation process and the thermal stability of the aqueous gelatin solution by reducing the gelation time and improving the mechanical properties of the gel in terms of network elasticity.

Melt-blown fiber mat interleaving enhances the performance of single-polypropylene composites

In this study, we demonstrate that integrating melt-blown fiber mat interleaves into single-polypropylene composites enhances several mechanical properties and influences the morphology positively. Polypropylene veils were generated by melt blowing. We then created single-polypropylene composites by film-stacking in which we applied a film as a matrix, a woven fabric as primary reinforcement, and the melt-blown fiber mats as interleaves. The tensile modulus was improved in the range of 20%–46%, and the interlaminar shear strength and the perforation energy at impact were increased by 17% and 14%, respectively, due to interleaving. Master curves were constructed from dynamic mechanical analysis frequency sweep tests based on the time–temperature superposition principle. The storage modulus significantly increased while the tanδ decreased. The interleaving considerably reduced the delamination by creating a net-like structure leading to superior interfacial adhesion. The interleaving demonstrated in this study can promote single-polymer composites’ utilization in various engineering applications where high toughness and impact resistance are required.

How hydrocolloids can control the viscoelastic properties of acid-swollen collagen pastes

The interactions between proteins and polysaccharides are of considerable importance in the food industry. In this study, the effect of adding non-charged methylcellulose (MC), hydroxypropylmethylcellulose (HPMC), medium (GM) and high (GH) molecular weight guar gum and negatively charged sodium carboxymethylcellulose (CMC) was investigated on the rheological and thermal properties of acid-swollen collagen pastes, as a function of collagen concentration. Dynamic frequency sweeps showed that the addition of the hydrocolloids, except for CMC, increased the storage modulus (G′) and loss modulus (G″) of collagen pastes at all collagen levels investigated. MC, HPMC, GH, and GM increased the collagen pastes' storage modulus to a similar extent. In contrast, the values of the loss moduli were found to be markedly different for each hydrocolloid. The loss factor (tan δ) showed that incorporating the hydrocolloids made the pastes less elastic than pure collagen pastes. The phase transition temperature of collagen measured during the temperature sweep tests was not affected by MC, HPMC, GH, and GM. However, CMC shifted the transition temperature of collagen to higher temperatures. Micro Differential scanning calorimeter (microDSC) results showed that the presence of MC, HPMC, and guar gums did not affect the denaturation temperature (Td) and enthalpy (ΔH). In contrast, the addition of CMC increased the denaturation temperature and denaturation enthalpy of collagen pastes. By fixing the hydrocolloids' viscosifying power and changing the collagen concentration, collagen pastes with different hydrocolloids show different viscoelastic properties.

Investigation on effect of ionic liquid on CO2 separation performance and properties of novel co-casted dual-layer PEBAX-ionic liquid/PES composite membrane

Dual-layer composite membranes composed of Pebax 1657, different 1-Ethyl-3-methylimidazolium tetrafluoroborate ([Emim][BF4]) contents and Polyethersulfone (PES) were fabricated by co-casting method, to investigate CO2/light gases separation, due to the high affinity of CO2 to Pebax and the ionic liquid (IL). Gas permeation test, which was performed at 25 °C and pressure range of 4–8 bar, indicated remarkable increment in CO2, CH4 and N2 permeance through membranes, especially CO2, as well as ideal CO2/CH4 and CO2/N2 selectivities, with IL increment. At 6 bar, CO2 permeance increased 152.97% meanwhile, at 8 bar, CO2/CH4 and CO2/N2 selectivities increased 59.22% and 28.64%, respectively, in the membrane containing 20 wt. % IL, which is the optimum IL content. In addition, CO2 permeance and selectivity increased with pressure. FTIR, XRD, DSC, SEM, dynamic frequency sweep, contact angle and tensile test results revealed the formation of defect-free dense Pebax/IL top-layer on porous PES sub-layer. IL addition led to formation of new bonds between the IL and Pebax which cause changes in the chain packing and crystallinity of Pebax and fabrication of more amorphous top-layer and more porous sub-layer. These results are confirmed by decrement in the mechanical properties of Pebax/IL casting solutions and composite membranes, by IL increment.

Viscoelastic Property of an LDPE Melt in Triangular- and Trapezoidal-Loop Shear Experiment.

The time-dependent viscoelastic behaviors of a low-density polyethylene melt (LDPE) in a triangular- and trapezoidal-loop shear experiment reported previously are described here by an integral-type Rivlin–Sawyers (RS) constitutive equation. The linear viscoelasticity of the melt was obtained through a dynamic frequency sweep experiment at a small strain and fitted by a relaxation spectrum. The nonlinear viscoelasticity was characterized by viscosity. All the experimental viscoelastic behaviors of the melt can be divided into two types in terms of the predictions of the RS model: (1) predictable time-dependent viscoelastic behaviors at low shear rates or during short-term shear, and (2) unpredictable shear weakening behavior occurring at the high shear rate of 3–5 s−1 during long-term shear with the characteristic time interval of about 40–100 s. The influence of experimental error caused possibly by inhomogeneous samples on the viscoelasticity of the melt was analyzed, and the large relative error in the experiment is about 10–30%.

Long-term stiffness prediction of particle filled polymers by dynamic mechanical analysis: Frequency sweep versus creep method

The long-term service life of polymers can be estimated with much shorter experiments by applying the time temperature superposition principle (TTS). In this approach, data is obtained at different temperatures, usually through a stepped isothermal method (SIM) on the same sample. Dynamic mechanical analysis (DMA) instruments offer two different measurement methods to obtain SIM data: (i) static creep tests and (ii) dynamic frequency sweeps. This paper compares both methods on highly graphite filled polypropylene. Our studies on reproducibility of each method show that the uncertainty for 20 year prediction can be lower than 6% for both methods. While creep-based tests require a shorter experimental time, frequency sweep based tests show a lower scatter on the final result. The two main factors introducing uncertainty on the end results are related to (i) the reproducibility of the experimental raw data and (ii) the TTS optimisation using shift factors. The optimisation of the shift factors by a numerical method improves the accuracy of the master curve. By comparing creep and frequency sweep SIM, it shows that for predictions of one decade, the methods deliver very comparable results (less than 10% difference). For longer predictions, the methods differ and are not interchangeable. Furthermore, DMA was also effectively used as a three-point bending setup, providing information about strain rate sensitivity and the linear visco-elastic region using the same test setup and same sample dimensions as for TTS.

Structural, functional, rheological, and biological properties of the swim bladder collagen extracted from grass carp (Ctenopharyngodon idella)

The objective of this study was to develop an aquatic collagen with high thermal stability as a possible alternative to terrestrial sources. Swim bladder collagen (SBC) was extracted from grass carp with high yield of 39.2% (db), and characterized as type I collagen. X-ray diffraction indicated that SBC maintains a native triple helical collagen structure. Secondary structure analysis revealed that SBC consists of 41.93% α-helices, 45.31% β-sheets, 12.76% β-turns, and 0% random coils. Proteins from SBC exhibited foaming and emulsifying superiority to proteins from terrestrial sources, such as chicken feet collagen. The thermal denaturation temperature of SBC (34.3 °C) is similar to porcine skin collagen. Dynamic frequency sweep tests showed that elasticity plays a dominant role in the SBC solution system as the concentration increases. The SBC solution system shows viscous behavior when the temperature is below Td. In addition, the steady shear tests showed that all of the SBC solutions exhibited pseudoplasticity with shear-thinning behavior. SBC could provide a suitable environment for MC3T3-E1 cell growth and maintain normal cellular morphology. Overall, the results indicated that SBC might has potential for further applications in food, cosmetics and biomedical fields.

Characterization of the rheological behavior of a paraffin-based phase change material under steady and oscillatory shear

Solid-liquid phase change materials (PCMs) behavior has been extensively discussed through a set of numerical and experimental investigations. In the current numerical models, natural convection dominated melting is often neglected due to a lack of experiments aiming to characterize the PCM behavior during the melting state. However, it was observed that ignoring this phenomenon causes a large difference between numerical results and experimental data. Hence, natural convection has to be accounted in order to correctly describe the physics encounter in the phase change, especially during melting process. Since natural convection phenomenon depends on the PCM viscosity, the rheological behavior of PCMs should be evaluated properly. In this study, the rheology of RT25, one of the frequently used phase change materials in domestic comfort services, has been described using a Kinexus Lab Rotational Rheometer. Both rotational and oscillatory methods have been used to measure the zero-shear viscosity and the dynamic viscosity which are important parameters of CFD simulations. The Newtonian behavior of RT25 was also demonstrated through dynamic frequency sweep measurements. Moreover, influence of several parameters on the rheological properties has been analyzed.

Evaluation of technological properties, microstructure and predictive glycaemic response of durum wheat pasta enriched with psyllium seed husk

Psyllium seed husk (PSH) is a soluble dietary fibre with interesting health benefits, including reduction in blood glucose level in subjects with type 2 diabetes. Its supplementation in pasta represents a challenge due to a negative impact of high PSH levels on product acceptability. The aim of this work was to investigate the effects of the substitution of semolina with different levels of PSH on cooking properties, microstructure and in vitro glycaemic response of pasta. Dry pasta samples enriched with PSH were produced by replacing durum wheat semolina with 25, 50, 75 and 100 g/kg PSH. Cooked enriched pastas were firmer and sticker than the control. Cooking loss increased with increasing PSH levels above 25 g/kg with values below the technological acceptable limit of 80 g/kg. Semolina substitution with 50–100 g/kg psyllium was effective in lowering the predictive glycaemic response of enriched pasta in comparison with the control. Scanning electron microscopy and dough rheology (dynamic frequency and temperature sweep tests) suggested that this decrease was related to the formation of fibre aggregates limiting starch swelling. Semolina replacement with 50 g/kg PSH has the potential to provide a health benefit with minimal impact on cooking features of functional pasta.