Temperature Ramp Tests Research Articles

Oscillatory and rotational rheological characterization of jackfruit peel cellulose suspension: Effect of concentration, pH and ionic strength

Jackfruit peel (JP) is considered as an agro-industrial lignocellulosic waste which can be utilized for cellulose isolation. In this work, a yield of 25.6% cellulose was obtained from JP powder through alkali (NaOH) and bleaching (NaClO2) treatment along with the elimination of lignin, hemicellulose and other non-cellulosic constituents. The IR spectroscopy confirmed the existence of cellulose content in the final extracted product. The SEM images and EDX spectra demonstrated the microstructure of cellulose fibrils and their major elemental components as carbon and oxygen, respectively. The XRD data validated the crystalline (69.42%) nature of the cellulose. The various rheological attributes of cellulose suspension like the flow properties and dynamic rheological characteristics were examined at different pH, ionic strength and cellulose concentration. The cellulose suspensions exhibited shear thinning nature for all the pH, ionic concentration and cellulose concentrations. The change in viscoelastic behaviour of the cellulose suspension was noticed with the rise in storage modulus (G′) value with ionic concentration. The pH of the cellulose suspension had a significant impact on its viscoelastic properties due to the modifications in interfibrillar interactions of cellulose fibrils. The temperature ramp test showed that the G’ is independent of the heating of cellulose suspension from 20 °C to 80 °C. The creep and thixotropic recovery test revealed that upon removal of stress, there is the recovery of strain and viscosity up to a certain extent, which is a characteristic property of viscoelastic material.

High temperature creep model development using in-situ 3-D DIC techniques during a simulated LOCA transient

In-situ strain measurements of fuel cladding can enable high-throughput data collection and validation to support accelerated qualification of cladding materials. In this work, 3D digital image correlation was used to map strain for both Zircaloy-4 (Zry-4) and Cr-coated Zry-4 during two types of cladding rupture experiments: isobaric temperature ramp tests at 5 °C/s and isothermal pressure jump tests at 600 °C. Zry-4 strain data initially showed a temperature dependence expected for creep deformation, yet a shift to a new plastic deformation mechanism not reported in literature dominated during the finals seconds prior to rupture. Cr-coated Zry-4 did not show the change in deformation mechanism at the end of life and showed a delay in measurable creep deformation. Stress dependences were similar for Zry-4 and Cr/Zry-4 during pressure jump tests. Cr-coatings were found to decrease the strain rate during both testing scenarios. Creep parameters were calculated to support modelling efforts regarding design basis accidents.

An Engineering Method for Resonant Microcantilever Using Double-Channel Excitation and Signal Acquisition Based on LabVIEW

Resonant microcantilevers have the advantages of ultra-high heating rates, analysis speed, ultra-low power consumption, temperature programming, and trace sample analysis when applied in TGA. However, the current single-channel testing system for resonant microcantilevers can only detect one sample at a time, and need two program heating tests to obtain the thermogravimetric curve of a sample. In many cases, it is desirable to obtain the thermogravimetric curve of a sample with a single-program heating test and to simultaneously detect multiple microcantilevers for testing multiple samples. To address this issue, this paper proposes a dual-channel testing method, where a microcantilever is used as a control group and another microcantilever is used as an experimental group, to obtain the thermal weight curve of the sample in a single program temperature ramp test. With the help of the LabVIEW’s convenient parallel running method, the functionality of simultaneously detecting two microcantilevers is achieved. Experimental validation showed that this dual-channel testing system can obtain the thermogravimetric curve of a sample with a single program heating test and detect two types of samples simultaneously.

Physical, structural, and rheological properties of γ-cyclodextrin metal-organic framework emulgels

AbstractThis study aimed to develop and characterise emulgels based on aqueous γ-cyclodextrin metal-organic framework (γ-CD-MOF) solutions with sunflower oil in the presence of Tween 20, 40, and 60 emulsifiers. The main physical, structural, and rheological properties of γ-CD-MOF emulgels were investigated. The emulgels prepared with 5% and 10% γ-CD-MOF were durable. The X-ray diffraction patterns proved the existence of β polymorph type lipid crystals. The rheological analyses showed that the gel strength increased with increased γ-CD-MOF concentration, and thixotropic behaviour was observed depending on the gel strength at 10 °C. In addition, the samples were heat resistant proved by rheological temperature ramp tests. Finally, addition of the emulsifiers did not cause any change in the centrifuge stability and colour properties of the emulgels. These samples could be used to prepare different emulsion type food products.

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.

Methylcellulose-Chitosan Smart Gels for Hairstyling

Methylcellulose and chitosan served as promising ingredients for a thermoresponsive hair styling gel after successful application in the medical industry. Both ingredients uphold the clean beauty standard without infringing on performance. By combining these two ingredients, a hair gel can be created that promises an extended hold of style once a heated external stimulus, such as a curling wand, is applied to the hair. Chitosan serves as the cationic biopolymer to adhere the gel to the hair, whereas the methylcellulose acts as the smart biopolymer to lock the desired hairstyle in place. Various ranges of chitosan and methylcellulose concentrations were explored for formulation optimization with rheology and curl drop testing. The rheology testing included a flow sweep test to understand the shear-thinning behavior of the sample as well as the effect of concentration on viscosity. Another rheology test completed was a temperature ramp test from room temperature (25 °C) to 60 °C to study the effect of heat on the various concentrations within the samples. A curl drop test was performed as well, over a 48-h period in which the different samples were applied to wet hair tresses, dried, curled, and hung vertically to see how the style held up over a long period of time with the influence of gravity.

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.

Processing and Characterization of Bioplastics from the Invasive Seaweed Rugulopteryx okamurae.

The seaweed Rugulopteryx okamurae, from the Pacific Ocean, is considered an invasive species in the Mediterranean Sea. In this work, the use of this seaweed is proposed for the development of bio-based plastic materials (bioplastics) as a possible solution to the pollution produced by the plastic industry. The raw seaweed Rugulopteryx okamurae was firstly blended with glycerol (ratios: 50/50, 60/40 and 70/30), and subsequently, they were processed by injection molding at a mold temperature of 90, 120 and 150 °C. The rheological properties (frequency sweep tests and temperature ramp tests) were obtained for blends before and after processing by injection molding. The functional properties of the bioplastics were determined by the water uptake capacity (WUC) values and further scanning electron microscopy (SEM). The results obtained indicated that E’ was always greater than E”, which implies a predominantly elastic behavior. The 70/30 ratio presents higher values for both the viscoelastic moduli and tensile properties than the rest of the systems (186.53 ± 22.80 MPa and 2.61 ± 0.51 MPa, respectively). The WUC decreased with the increase in seaweed in the mixture, ranging from 262% for the 50/50 ratio to 181% for the 70/30 ratio. When carrying out the study on molded bioplastic 70/30 at different temperatures, the seaweed content did not exert a remarkable influence on the final properties of the bioplastics obtained. Thus, this invasive species could be used as raw material for the manufacture of environmentally friendly materials processed by injection molding, with several applications such as food packaging, control–release, etc.

A polysaccharide from Lignosus rhinocerotis sclerotia: Self-healing properties and the effect of temperature on its rheological behavior

This work investigated the self-healing properties of Lignosus rhinocerotis polysaccharide (LRP) and the effect of temperature on its rheological behavior. Dynamic sweep tests (strain sweep, frequency sweep, and time sweep) showed that the LRP/water system possessed self-healing properties due to the entangled network formed by hyperbranched LRP molecular chains. The flow activation energy of LRP solution calculated by Arrhenius equation was shown to decrease with increasing LRP concentration, indicating that LRP solution at higher concentration was less sensitive to temperature. Temperature ramp test exhibited that LRP had a glass transition temperature (Tg) determined as 49.35 °C and the temperature effect was irreversible. Microrheological test revealed that the LRP aqueous solution can form a gel at room temperature with the concentration ≥ 20 mg/mL. This work provided a theoretical basis for the development of LRP-based self-healing materials and facilitated a deep understanding of the temperature effect on rheological behavior of LRP.

Influence of UV Polymerization Curing Conditions on Performance of Acrylic Pressure Sensitive Adhesives.

Acrylic pressure sensitive adhesives (PSAs) were prepared by UV polymerization under varying curing conditions of both fast and slow curing, employing high- and low-intensity UV radiation, respectively. The influences of curing conditions and isobornyl acrylate (IBOA) content on PSA performance were comprehensively investigated by measurement of their rheological, thermal, and adhesive properties. In particular, rheological characterization was accomplished by several analytical methods, such as in situ UV rheology, frequency sweep, stress relaxation, and temperature ramp tests, to understand the effect of the UV curing process and IBOA content on the viscoelastic behavior of acrylic PSAs. The slow-cured samples were observed to form more tightly crosslinked networks compared to the fast-cured. On the other hand, at high loading levels of IBOA, in the case of slow curing, the sample exhibited a contrasting trend, having the shortest stress relaxation time and the highest energy dissipation; this was due to molecular chain scission occurring in the crosslinked polymer during UV polymerization. Consequently, we successfully demonstrated the influence of monomer composition of acrylic PSAs, and that of curing conditions employed in UV polymerization. This study provides valuable insights for the development of crosslinked polymer networks of acrylic PSAs for flexible display applications.

Rheological behavior of bitumen modified by reclaimed polyethylene and polypropylene from different recycling sources

AbstractThis work studied the rheological, thermal, and mechanical properties of bitumen modified by reclaimed polyethylene (PE), and polypropylene (PP) from different recycling sources. The rutting resistance under high temperature of polymer modified bitumen (PMB) was investigated by rheologically temperature ramp test and multiple stress creep recovery (MSCR) test. It is found that for some modified bitumen, a plateau of complex modulus G* could be formed with temperature increment, revealing rheological stability. Furthermore, these samples with rheological stability revealed a higher creep recovery and lower creep compliance measured by the MSCR test. Glass transition temperature (Tg) measured by dynamic mechanical analysis was used to evaluate the crack resistance under a low temperature of PMB. The influence of recycled PE on the Tg of modified bitumen was different from that of recycled PP modified bitumen, as compared with corresponding virgin polymer modified bitumen. A possible reason for the various effect of recycling sources on the service property of modified bitumen was explored by crystallization and melting behaviors of polymer in bitumen since that polymer with higher crystallinity degree could endow the modified bitumen stiffness, which was closely, related to their service property especially the rutting resistance.

Preparation and characterization of oleogels and emulgels with glycerol monooleate–cholesterol mixtures

This study aimed to prepare and characterize oleogels and emulgels with glycerol monooleate (GMO): cholesterol gelator system. Oleogels, including 5 and 10% of each gelator were prepared. Emulgels with the same organogelator mixture concentrations, and 10 and 20% water phase were also prepared successfully. The gelation time decreased as the added gelator mixture and water concentrations increased. All samples had significant oil binding capacity and creamish-white colors. The oleogels melted just below body temperature, while emulgels melted around body temperature as determined by differential scanning calorimetry. The samples’ crystalline networks were observed with the X-ray diffraction analysis and displayed β and β′ polymorphic type crystals. Rheological measurements revealed that as gelator mixture concentration increased, gel strength enhanced, but in the emulgels, the gel strength decreased significantly as added water content increased. All oleogels and emulgels showed time-dependent thixotropic recovery ability. Temperature ramp tests indicated that the oleogels were stable up to 28 °C, but the emulgels kept their gelled consistency up to 70 °C. Overall, the common properties of these new oleogel and emulgels were provided. Future studies for some applications are foreseen.

Using Poloxamer® 407 as Building Block of Amphiphilic Poly(ether urethane)s: Effect of its Molecular Weight Distribution on Thermo-Sensitive Hydrogel Performances in the Perspective of Their Biomedical Application

Due to its hydroxyl terminal groups, Poloxamer® 407 (P407), a commercially available poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) (PEO-PPO-PEO) triblock copolymer can be used as macrodiol for the synthesis of high molecular weight amphiphilic poly(ether urethane)s (PEUs). This work was aimed at studying the effect of P407 purification by removing PEO-PPO diblock copolymer by-products on the chemical properties of PEU polymer and the physical properties of PEU hydrogels. Removal of PEO-PPO diblock copolymers (P407_P) was found to preserve the thermo-responsiveness of resulting hydrogels, although slightly lower gelation onset temperature (Tonset) was found for P407_P (15.3°C) vs. P407 (16.7°C) hydrogels (25% w/V) as assessed through temperature ramp test. P407 and P407_P were then reacted with 1,6-diisocyanatohexane and 1,4-cyclohexanedimethanol to synthesize two different PEUs, coded as CHP407 and CHP407_P, respectively. Lower Number Average Molecular Weight (Mn¯) and higher polydispersity Index (D) was measured for CHP407 (Mn¯: 34 kDa, D: 1.6) respect to CHP407_P (Mn¯: 40 kDa, D: 1.4) as a consequence of macrodiol purification. CHP407_P hydrogels formed bigger micelles (43.9 ± 4.1 nm vs. 28.7 ± 4 nm) while showed similar critical micellar temperatures (22.1°C vs. 21.6°C) respect to CHP407 formulations. Sol-to-gel transition of CHP407 and CHP407_P hydrogels was similar while CHP407_P gelation time at 37°C was longer as assessed by tube inverting test. The rheological analysis showed slightly lower Tonset for CHP407_P hydrogels (15% w/V), probably due to larger micelle size, promoting micellar assembly. However, CHP407_P hydrogels showed a significantly lower critical strain than CHP407 hydrogels, as assessed by strain sweep test, suggesting their higher brittleness due to a lower density of intermicellar bridge chains. Nano-scale hydrogel characterization by Low-Field Nuclear Magnetic Resonance spectroscopy supported previous findings, showing lower spin-spin relaxation time (i.e., 1,259 ms) for CHP407_P than for CHP407 hydrogels (i.e., 1,560 ms) at 37°C, which suggested the formation of a more tightly packed network for CHP407_P than CHP407 hydrogel. Finally, lower swelling capability and resistance against dissolution were measured for CHP407_P hydrogels. Overall, the here‐reported results suggested that the heterogeneous structure in the CHP407 hydrogel network caused by the presence of diblock copolymer-based macrodiols improved PEU hydrogel properties in light of their applicability in the biomedical field.

Impact of Germination and Fermentation on Rheological and Thermo-Mechanical Properties of Wheat and Triticale Flours

Common cereal processing through germination and fermentation usually has an important impact on the technological performance of the flours, mainly because of the activation of endogenous enzymes acting on macromolecules. The aim of the present study is to estimate the effect of germination and fermentation, using a mixture of Lactobacillus casei and Kluyveromyces marxianus subsp. marxianus, on the rheological properties of different wheat and triticale varieties. Moreover, the thermo-mechanical behaviour of the white wheat flour-based dough, including germinated grain flour or sourdough was also tested. Grains germination and sourdough fermentation exerted a high influence on the rheological behaviour of the flour-based suspensions. Germination affected the structure and stability of the suspensions, resulting in samples with viscous behaviour prevailing over the elastic one. The temperature ramp tests revealed that germination together with fermentation lead to higher resistance to temperature changes. In agreement with the results of the rheological investigations on rheometer, the Mixolab test performed on flour obtained from germinated grains revealed lower dough stability and protein weakening at temperature increase. On the other hand, a significant improvement of the pasting properties of the dough was obtained when adding sourdoughs to the wheat flour.

Gelation kinetics of aqueous gelatin solutions in isothermal conditions via rheological tools

We investigate the sol-gel transition of aqueous pig-skin gelatin solutions at different concentrations and temperatures. In particular, we characterize the isothermal gelation kinetics close to the critical melting temperature, previously evaluated with dynamic temperature ramp tests. The time evolution of the moduli is analyzed at a specific fixed frequency and at various temperatures and concentrations. The isothermal study allows to evaluate the gel time and to determine its dependence on concentration and temperature.The study of the gelation kinetics over a wide range of concentrations allows to link the behavior in solution to the gelation phenomenon, confirming a different temperature dependence of the sol-gel transition according to the concentration regimeAlthough some models are available to describe this dependence, they do not simultaneously account for the effect of both parameters (i.e. temperature and concentration). Here, we propose a full empirical model that accommodates the dependence upon both temperature and concentration.

The rheological properties and gelation kinetics of corn starch/bovine serum albumin blend

The rheological properties and gelation kinetics of corn starch (CS)/bovine serum albumin (BSA) blends were investigated using the mass ratio of [CS]/[BSA] of 0, 0.5, 1, 2, and 3. The results from the temperature ramp and time sweep tests within linear viscoelastic regime showed a decrease in the gelation temperature (Tgel) and gelation time (tgel) of the BSA with increasing the mass ratio of [CS]/[BSA]. A significant decrease in the Tgel and tgel occurred at 5 wt.% BSA with [CS]/[BSA] = 3, where about 12 °C and 11 min drops in the Tgel and tgel were recorded. At the molecular scale, the decrease in the Tgel and tgel with increasing the mass ratio of [CS]/[BSA] was attributed to the breaking down of hydrogen bonding sites in the CS molecules with increasing temperature, and thereby allowing the hydroxyl group to engage in intermolecular hydrogen bonding with the BSA polar amino acid residues. The hydrogen bonding in addition to other non-covalent forces appeared to strengthen the microstructure of the CS/BSA gel as confirmed by the dynamic frequency sweep test. The frequency sweep test also showed that the value of the storage modulus (G′) at [CS]/[BSA] = 3 was about 10 to 103 orders of magnitude larger than its value recorded for the pure BSA. Kinetically, the gelation process was well modelled by the temperature dependency of reaction rate constant as represented by the Arrhenius equation. If interpreted in terms of the energy required to attain the gel state, the addition of CS reduced the gel activation energy (Ea) to 153.90 kJ/-mol as against the original value of 268.55 kJ/mol that was observed for the BSA without CS.

Effects of ultrasonicated methylcellulose coating on French fries during deep frying process

AbstractUltrasonic treatment (UT) effects on methylcellulose (MC) for the food coating purpose prior to deep‐fat frying process of potato strips were demonstrated. Different concentration of MC (0.5–2.0 wt/vol%) solutions were subjected to UT at 20 W to evaluate the effect of UT treated coatings on rheological behavior of the coated samples and their efficiency in minimizing the oil uptake. Application of UT to methylcellulose (UTMC) clearly showed a phase transition from fluid‐ to gel‐like between 20 and 65°C with the increasing in the oscillatory frequency and temperature ramp test of UTMC showed the sol–gel transition occurrence is lower than non‐UTMC at 20 and 29°C, respectively, within the linear viscoelastic region. When the MC concentrations were varied, the most effective concentration was noticed to occur at 1.0 (wt/vol%) UTMC whereby the relative variation of water retention and oil uptake were reduced to about 49.9 and 31.0%, respectively, as compared to 1.0 wt/vol% non‐UTMC formulation. Experimental results affirm that UTMC coating application can be used successively to improve rheological properties of MC by minimizing oil uptake on fried food.Practical ApplicationUltrasonic treatment (UT) application to methylcellulose (MC) solutions with varied concentration (0.5–2.0 wt/vol%) clearly showed a phase transition from fluid‐to‐gel like with the increasing in the oscillatory frequency (10−1 to 102 rad/s) and temperature ramp test (65–10°C) at low shear strains compared to non‐UTMC. The gelation of UTMC was faster than non‐UTMC when coated onto the substrate at the ambient conditions thus allowed the transformation of green coating layer to form the gel layer instantaneously. Application of MC was successfully in minimizing oil uptake on fried potato strips whereby the most effective layer was noticed to occur at 1.0 wt/vol% UTMC. Introducing UT to polysaccharide coating, that is, MC benefit the food coating industries by increasing the food coating process efficiency so that the coated layer can be fully utilized to increase the function of the coated substrate.

Effect of selected printing settings on viscoelastic behaviour of 3D printed polymers with and without wood

The viscoelastic behaviour of 3D printed samples produced from different types and contents of commercially produced filaments of wood and thermoplastics at different printing settings was investigated in this study. An Ares G2 rheometer was used to carry out the dynamic mechanical analysis (DMA) of the printed materials. A strain sweep and a temperature ramp test were made to evaluate the effect of 3D printing settings, materials, and temperature on the properties of the 3D-printed specimens. Five different printing materials (ABS, PLA, co-polyesters, mixtures with different wood content) and three printing layer thicknesses (0.09, 0.19, 0.29 mm) were used. The result showed that the specimens printed from Filament C (polymer blend of co-polyesters) had the lowest storage modulus while the highest modulus was found in the PLA based samples. When comparing pure PLA and PLA-wood filaments, the addition of wood particles decreased the storage modulus by 40%. The glass transition temperature (Tg) of the materials differed with each other. The specimens printed from ABS had the highest Tg 115 °C, followed by the specimens printed from co-polyester-based filament (around 70 °C), pure PLA, and PLA-wood filaments (64 °C–66 °C). The addition of wood did not change the glass transition temperature, since the main matrix was made of polymer. The viscoelastic behaviour of the 3D printed neat polymer and wood/polymer parts produced at different processing parameters and conditions can be considered for filament producers for material selection and the design engineers when wood/PLA printed parts fabricated through FDM technique.

Bioplastics based on wheat gluten processed by extrusion

Abstract Recently, bioplastic have generated an increasing interest as an alternative to conventional plastics. For this reason, their manufacture using the traditional techniques used for the production of plastics, such as extrusion, would help transferring bioplastics production to an industrial scale. In this way, the preparation of wheat gluten bioplastics by extrusion was the main objective of this research, modifying their structure by varying the pH value or by incorporating additives (glyoxal or xanthan gum). These bioplastics were characterized by the measurement of their mechanical properties and their water uptake capacity, proving that the modification of bioplastics cause variations in their properties. Thus, extrusion resulted in a greater gluten-plasticizer compatibility compared to compression, as denoted the temperature ramp tests, especially in the presence of additives (ie. Xanthan gum, glyoxal). Moreover, tensile strength was enhanced at pH 9, probably due to bonding promotion at alkaline conditions. These results demonstrate the great potential of these materials for the replacement of conventional plastics.

Impact of broad beans addition on rheological and thermal properties of wheat flour based sourdoughs

Broad bean flour is a valuable source of proteins and micronutrients and can efficiently balance the nutritional value of wheat flour. The aim of the study was to assess the impact of wheat flour substitution by native and germinated broad beans on the water related, thermal and rheological properties of the composite flours and sourdoughs. Regardless of the investigated flour, temperature increase resulted in significant decrease of water soluble index. Addition of broad bean to wheat flour affected the swelling power. Differential scanning calorimetry measurements on flours indicated two peaks at ∼70 °C assigned to starch gelatinization, and ∼100 °C attributed to amylose-lipids complexes disruption. The same thermal dependent events were highlighted through the rheometric temperature ramp test. Sourdoughs were further obtained out of the composite flours and dynamic rheometric analysis showed that fermentation improved flow resistance. Wheat substitution by broad bean flour increased sourdoughs consistency due to the higher protein content.