RÉSUMÉ
The tribological properties of 19 commercial food products, grouped into six categories (yogurt, dressings, spreads, porridges, emulsified sauces, and syrups) were investigated in relation to their rheological (dynamic oscillatory shear test) and nutritional properties (fat, carbohydrate, and protein). A tribological system (a glass ball and three polydimethylsiloxane pins) generated the extended Stribeck curve, monitoring friction factors (f) over an extended range of sliding speed (v) (10-8 to 100 m/s). Tribological parameters (f, v) at four inflection points dividing the frictional regimes (X1, breakaway point between the static and kinetic regimes; X1-X2, boundary; X2-X3, mixed; X3-X4, hydrodynamic regimes) and the slope between X3 and X4 (s) were subjected to principal component analysis and hierarchical clustering on principal components, using rheological and nutritional parameters as quantitative supplementary variables. Tribological patterns were predominantly influenced by viscosity, viscoelasticity, yield stress, fat content, and the presence of particles (e.g., sugar, proteins, and fibers) and pasting materials (e.g., starches and modified starches). The 19 tribological patterns were classified into 3 clusters: low f and s for fat- and/or viscoelastic-dominant foods (Cluster 1), low f and high s for food emulsions and/or those with low extent of shear-thinning (Cluster 2), and high f at the boundary regime either for the most viscous foods or for those in the presence of particulates (Cluster 3). These results suggest that the compositional and rheological properties have a more profound impact on the classification of complex tribological patterns than the categories of food products.
Sujet(s)
Valeur nutritive , Rhéologie , Viscosité , Élasticité , Aliments , Friction , Analyse d'aliment , Analyse en composantes principalesRÉSUMÉ
Ballistic impacts on human thorax without penetration can produce severe injuries or even death of the carrier. Soft tissue finite element models must capture the non-linear elasticity and strain-rate dependence to accurately estimate the dynamic human mechanical response. The objective of this work is the calibration of a visco-hyperelastic model for soft tissue simulants. Material model parameters have been calculated by fitting experimental stress-strain relations obtained from the literature using genetic algorithms. Several parametric analyses have been carried out during the definition of the optimization algorithm. In this way, we were able to study different optimization strategies to improve the convergence and accuracy of the final result. Finally, the genetic algorithm has been applied to calibrate two different soft tissue simulants: ballistic gelatin and styrene-ethylene-butylene-styrene. The algorithm is able to calculate the constants for visco-hyperelastic constitutive equations with high accuracy. Regarding synthetic stress-strain curves, a short computational time has been shown when using the semi-free strategy, leading to high precision results in stress-strain curves. The algorithm developed in this work, whose code is included as supplementary material for the reader use, can be applied to calibrate visco-hyperelastic parameters from stress-strain relations under different strain rates. The semi-free relaxation time strategy has shown to obtain more accurate results and shorter convergence times than the other strategies studied. It has been also shown that the understanding of the constitutive models and the complexity of the stress-strain objective curves is crucial for the accuracy of the method.
Sujet(s)
Algorithmes , Élasticité , Analyse des éléments finis , Contrainte mécanique , Humains , Viscosité , Modèles biologiques , Phénomènes biomécaniques , Gélatine/composition chimiqueRÉSUMÉ
Silk fibers' unique mechanical properties have made them desirable materials, yet their formation mechanism remains poorly understood. While ions are known to support silk fiber production, their exact role has thus far eluded discovery. Here, we use cryo-electron microscopy coupled with elemental analysis to elucidate the changes in the composition and spatial localization of metal ions during silk evolution inside the silk gland. During the initial protein secretion and storage stages, ions are homogeneously dispersed in the silk gland. Once the fibers are spun, the ions delocalize from the fibroin core to the sericin-coating layer, a process accompanied by protein chain alignment and increased feedstock viscosity. This change makes the protein more shear-sensitive and initiates the liquid-to-solid transition. Selective metal ion doping modifies silk fibers' mechanical performance. These findings enhance our understanding of the silk fiber formation mechanism, laying the foundations for developing new concepts in biomaterial design.
Sujet(s)
Bombyx , Cryomicroscopie électronique , Fibroïne , Soie , Bombyx/métabolisme , Animaux , Soie/composition chimique , Soie/biosynthèse , Soie/métabolisme , Fibroïne/composition chimique , Fibroïne/métabolisme , Ions , Métaux/composition chimique , Métaux/métabolisme , Séricines/composition chimique , Séricines/métabolisme , ViscositéRÉSUMÉ
Red seaweed carrageenans are frequently used in industry for its texturizing properties and have demonstrated antiviral activities that can be used in human medicine. However, their high viscosity, high molecular weight, and low skin penetration limit their use. Low-weight carrageenans have a reduced viscosity and molecular weight, enhancing their biological properties. In this study, ι-carrageenan from Solieria chordalis, extracted using hot water and dialyzed, was depolymerized using hydrogen peroxide and ultrasound. Ultrasonic depolymerization yielded fractions of average molecular weight (50 kDa) that were rich in sulfate groups (16% and 33%) compared to those from the hydrogen peroxide treatment (7 kDa, 6% and 9%). The potential bioactivity of the polysaccharides and low-molecular-weight (LMW) fractions were assessed using WST-1 and LDH assays for human fibroblast viability, proliferation, and cytotoxicity. The depolymerized fractions did not affect cell proliferation and were not cytotoxic. This research highlights the diversity in the biochemical composition and lack of cytotoxicity of Solieria chordalis polysaccharides and LMW fractions produced by a green (ultrasound) depolymerization method.
Sujet(s)
Carragénane , Masse moléculaire , Rhodophyta , Humains , Rhodophyta/composition chimique , Carragénane/pharmacologie , Oligosaccharides/pharmacologie , Oligosaccharides/composition chimique , Oligosaccharides/isolement et purification , Polyosides/pharmacologie , Polyosides/composition chimique , Polyosides/isolement et purification , Fibroblastes/effets des médicaments et des substances chimiques , Peroxyde d'hydrogène , Survie cellulaire/effets des médicaments et des substances chimiques , Prolifération cellulaire/effets des médicaments et des substances chimiques , Polymérisation , Ondes ultrasonores , ViscositéRÉSUMÉ
Noninvasive in situ monitoring of viscoelastic characteristics of corneal tissue at elevated temperatures is pivotal for mechanical property-informed refractive surgery techniques, including thermokeratoplasty and photorefractive keratectomy, requiring precise thermal modifications of the corneal structure during these surgical procedures. This study harnesses Brillouin light scattering spectroscopy as a biosensing platform to noninvasively probe the viscoelastic properties of ovine corneas across a temperature range of 25-64 °C. By submerging the tissue samples in silicone oil, consistent hydration and immiscibility are maintained, allowing for their accurate sensing of temperature-dependent mechanical behaviors. We identify significant phase transitions in the corneal tissue, particularly beyond 40 °C, likely due to collagen unfolding, marking the beginning of thermal destabilization. A subsequent transition, observed beyond 60 °C, correlates with collagen denaturation. These phase transformations highlight the cornea's sensitivity to both physiologically reversible and irreversible viscoelastic changes induced by mild to high temperatures. Our findings underscore the potential of the Brillouin biosensing technique for real-time diagnostics of corneal biomechanics during refractive surgeries to attain optimized therapeutic outcomes.
Sujet(s)
Techniques de biocapteur , Cornée , Élasticité , Animaux , Ovis , Viscosité , Transition de phase , TempératureRÉSUMÉ
Individual cells are the smallest units of the plant tissue structure, and their structure and physicochemical properties are essential for whole food processing. In this study, cassava cells were isolated using acid-alkali, hydrothermal, and pectinase methods, and the differences in microstructure and physicochemical properties among the cells, starch, and whole flour were investigated. Cassava cells isolated using pectinase showed intact individual cells with a higher isolation rate and less damage to the cell wall structure and intracellular composition. The presence of cell walls in intact individual cells inhibited the swelling and leaching of starch, resulting in a lower peak viscosity and higher gelatinization temperature than those of starch. The intact cell structure and non-starch composition enhanced the shear resistance of the gels in the sample. Heat treatment led to the gelatinization of intracellular starch and increased the permeability of the cell wall, destroying the physical barrier function of the cell wall; however, the compact cell matrix and non-starch components can inhibit starch hydrolysis. This study suggests that cells isolated using pectinase can be used to investigate the effect of cell walls on the functional properties of intracellular starch in cassava. The isolated cells provide new insights into the cassava industry.
Sujet(s)
Paroi cellulaire , Farine , Manihot , Amidon , Manihot/composition chimique , Amidon/composition chimique , Farine/analyse , Paroi cellulaire/composition chimique , Viscosité , Polygalacturonase/métabolisme , Polygalacturonase/composition chimique , HydrolyseRÉSUMÉ
The demand for plant-based products has increased in recent years, due to several aspects related to health and environmental consciousness. This study aimed to produce and characterize a plant-based dairy alternative dessert based on araticum pulp and chickpea extract without added sugar and fat. Three formulations were prepared: Formulation 1 (F1): 20% araticum pulp + 80% chickpea extract; Formulation 2 (F2): 30% araticum pulp + 70% chickpea extract; and Formulation 3 (F3): 40% araticum pulp + 60% chickpea extract. All formulations' chemical composition, sensorial characteristics, viscosity, total phenolic content, antioxidant activity, and microbiological stability were analyzed during 28 days of storage at 4°C and a relative humidity of 23%. Energetic value ranged from 64 to 71 kcal/100g, and carbohydrate content from 9.68 to 11.06, protein from 3.38 to 3.04, lipids from 1.41 to 1.60, ashes from 0.53 to 0.59 and crude fiber from 0.86 to 1.34 g/100g among the formulations. The increase in the proportion of araticum pulp in the formulations reduced moisture content by 1.2 to 2.1% (F1: 84.2, F2: 83.2, and F3: 82.4), protein content by 3 to 9% (F1: 3.3, F2: 3.2, and F3: 3.0), and pH value by 5.8 to 10.7% (F1: 5.50, F2: 5.18, and F3: 4.91), and increased the TSS by 1.1 to 1.3-fold (F1: 8.36, F2: 8.98, and F3: 10.63 º Brix), total phenolics content by 1.5 to 2.0-fold (F1: 4,677, F2: 6,943, and F3: 10,112 gallic acid µmol/L) and antioxidant activity by 1.8 to 2.8-fold (F1: 1,974, F2: 3,664, and F3: 5.523). During the 28 days of storage at 4°C, the formulations F1 and F2 showed better stability of phenolic compounds and antioxidant activity; however, the formulation F3 showed acceptable microbiological quality up to 28 days of storage, higher viscosity, 8 to 16-fold higher than the formulations F1 and F2, respectively (F1: 238.90, F2: 474.30, and F3:3,959.77 mPa.s), antioxidant capacity and better scores in sensory analysis. The present study showed that the plant-based dessert elaborated with araticum pulp and chickpea extract might be considered a potential dairy alternative product with high antioxidant activity, protein content, and a viscosity similar to yogurt; however, its sensory aspects need improvement.
Sujet(s)
Antioxydants , Cicer , Extraits de plantes , Cicer/composition chimique , Antioxydants/composition chimique , Antioxydants/analyse , Extraits de plantes/composition chimique , Humains , Viscosité , Phénols/analyse , Phénols/composition chimique , GoûtRÉSUMÉ
There is a significant opportunity to expand the understanding of subcutaneous injection mechanics with an aim to increase injectable volume while controlling tissue strain and associated subject pain. Computational modeling can evaluate the mechanics of subcutaneous injections as a supplement to experimental, animal and clinical studies. The objectives of this study are to (1) develop a computational model for subcutaneous injection in tissue, (2) investigate the influence anisotropic tissue permeability has on bolus formation, and (3) explore the effects that injection flow rate and viscosity have on injection flow and tissue strain. Poroelastic models with subsurface flow were implemented in finite element software (COMSOL, ABAQUS). Pore pressure and injectate distribution showed excellent agreement with experimental results when evaluated at multiple injection rates (20 ml/hr, 120 ml/hr and 360 ml/hr). Including the anisotropy of tissue permeability causes the injectate to preferentially spread horizontally, similar to experimentally observed bolus distributions. Cases are presented to provide additional insight into injection mechanics, including variations on the delivery rate, the injection volume, viscosity and the thickness of the subcutaneous layer. The results support the use of computational modeling as a valid tool for understanding tissue strains and injectate distributions for large volume injections.
Sujet(s)
Simulation numérique , Perméabilité , Pression , Injections sous-cutanées , Viscosité , Anisotropie , Humains , Analyse des éléments finis , Modèles biologiques , Animaux , Dynamique non linéaire , PorositéRÉSUMÉ
Activation against a hard surface according to ISO 11608-1 is not always representative of device use on a soft injection site. A softer injection site - which is an anthropometric property found in obese patients - presents a distinct viscoelastic property which can lead to greater autoinjector activation forces that are not captured in standardized activation testing methodology. Soft tissue simulation and physical testing were developed at SHL to advance the development of autoinjectors, allowing for rigorous testing and challenging these in scenarios involving even the softest injection sites.
Sujet(s)
Obésité , Humains , Simulation numérique , Conception d'appareillage , Injections sous-cutanées/instrumentation , Viscosité , Modèles biologiques , ÉlasticitéRÉSUMÉ
The higher viscosity and lower pH in lysosomes of cancer cells highlight their potential as biomarkers for cancer. Therefore, the development of acid-activated viscosity fluorescent probes is significant for the early diagnosis and treatment of cancer. Based on this, we have designed and synthesized a near-infrared fluorescent probe based on the 2-(2-hydroxyphenyl)benzothiazole (HBT) group, namely HBTH, to monitor the viscosity changes within lysosomes. It has been demonstrated that HBTH was extremely sensitive to viscosity, with a strong linear relationship between fluorescence intensity and log(viscosity) within the range of (logη) = 0-3.06 (a correlation coefficient of 0.98), proving its capability for quantitative viscosity measurement. In particular, the most obvious fluorescence enhancement of HBTH was only efficiently triggered by the combined effect of low pH and high viscosity. Furthermore, HBTH can rapidly localize to lysosomes by wash-free procedure at a low concentration (100 nM) and achieve high-fidelity imaging within 20 s. It can also monitor the dynamic processes of lysosomes in cells, viscosity changes under drug stimuli, and lysosomal behavior during mitophagy. Importantly, HBTH is capable of identifying tumors in tumor-bearing nude mice through in vivo imaging. These features make HBTH a powerful tool for the early diagnosis and treatment of cancer.
Sujet(s)
Colorants fluorescents , Lysosomes , Souris nude , Tumeurs , Lysosomes/métabolisme , Lysosomes/composition chimique , Colorants fluorescents/composition chimique , Colorants fluorescents/synthèse chimique , Animaux , Viscosité , Humains , Tumeurs/imagerie diagnostique , Tumeurs/traitement médicamenteux , Tumeurs/anatomopathologie , Souris , Concentration en ions d'hydrogène , Lignée cellulaire tumorale , Benzothiazoles/composition chimique , Benzothiazoles/pharmacologie , Souris de lignée BALB C , Imagerie optique , Mitophagie/effets des médicaments et des substances chimiquesRÉSUMÉ
Water occurrence states in sewage sludge, influenced by sludge physicochemical properties, are crucial for sludge dewaterability and have recently been regarded as a research hotspot. Here, the multifold characteristics of sludge flocs during hydrothermal treatment, including rheological properties, solid-water interfacial interactions, and the polarity distribution and molecular structure of extracellular polymeric substances (EPS), were systematically investigated, and the impact of these characteristics on sludge dewaterability was explored in depth. Hydrothermal treatment at 80 °C and 100 °C induced the conversion of free water into bound water, while an increase in temperature to 180 °C resulted in a significant decrease in bound water content, approximately 4-fold lower than at 100 °C. In addition to the conventional view of decreased sludge surface hydrophilicity at high temperatures, the decline in bound water was associated with the reduction in sludge apparent viscosity. XAD resin fractionation identified the hydrophobic/hydrophilic EPS (HPO-/HPI) ratio as an important factor determining water occurrence states. Especially, hydrolysis of HPI-related hydrophilic proteins and subsequent increase in HPO-related tryptophan-like substances played a dominant role in reducing sludge viscosity and facilitating the release of bound water. Protein conformational analysis revealed that the disruption of α-helix structures and disulfide bonds significantly reduced EPS water-holding capacity, providing strong evidence for the potential of targeting these dense structure units to enhance sludge dewaterability. These findings provide a holistic understanding of multidimensional drivers of water occurrence states in sludge, and guide directions for optimizing sludge treatment efficiency through EPS modification.
Sujet(s)
Matrice de substances polymériques extracellulaires , Eaux d'égout , Eaux d'égout/composition chimique , Matrice de substances polymériques extracellulaires/composition chimique , Eau/composition chimique , Interactions hydrophobes et hydrophiles , Élimination des déchets liquides , ViscositéRÉSUMÉ
The study pertains to preparing value added frozen yoghurt through use of orange peel powder (OPP). The quality aspects of medium-fat (6.0% fat) frozen yoghurt prepared using OPP at three levels (1.5, 2.5, 3.5% as T1, T2 and T3 respectively) was studied. Frozen yoghurt was prepared by freezing blend of fermented yoghurt base with ice cream mix (25:75 w/w); other ingredients were sugar, stabilizer-emulsifier and orange crush. Inclusion of OPP in frozen yoghurt impacted the orange flavour favorably and enriched product with ß-carotene and dietary fiber. The control product (TC) was prepared in similar manner, avoiding OPP. As the level of OPP was raised in formulation, there was a marked increase in the protein, carbohydrate, ash and total solids when compared with TC. Presence of OPP markedly affected the acidity, viscosity, overrun and melting resistance of the product; maximum overrun was associated with TC. Product T3 had the maximum acidity and viscosity; T2 had maximum total sensory score. It is recommended to prepare medium-fat frozen yoghurt utilizing 2.5% OPP along with orange crush as flavouring. Such inclusion of peel solids enriched the product with ß-carotene and dietary fiber, contributed to stabilization of product and enhanced the products sensory acceptance.
Sujet(s)
Fruit , Yaourt , Bêtacarotène , Yaourt/analyse , Fruit/composition chimique , Bêtacarotène/analyse , Congélation , Fibre alimentaire/analyse , Citrus sinensis/composition chimique , Humains , Manipulation des aliments/méthodes , Goût , ViscositéRÉSUMÉ
Rice bran protein fibril (RBPF)-high internal phase Pickering emulsions (HIPPEs) loaded with ß-carotene (CE) were constructed to enhance stability and bioavailability of CE. Rice bran (RB) protein with varying oxidation degrees was extracted from RB with varying storage period (0-10 days) to prepare RBPF by acid-heating (90 °C, 2-12 h) to stabilize HIPPEs. The influence of protein oxidation on the encapsulation properties of RBPF-HIPPEs was studied. The results showed that CE-HIPPEs could be stably stored for 56 days at 25 °C. When RB storage time was the same, the average particle size, lipid hydroperoxide content, and malondialdehyde content of CE-HIPPEs and the CE degradation rate initially fell, and then grew as the acid-heating time prolonged, while the ζ-potential value, viscosity, viscoelasticity, free fatty acid (FFA) release rate, and bioaccessibility first rose, and subsequently fell. When acid-heating time of RBPF was the same, the average particle size, lipid hydroperoxide content, and malondialdehyde content of CE-HIPPEs initially fell, and subsequently increased with RB storage time extended, while the ζ-potential value, viscosity, viscoelasticity, FFA release rate, and bioaccessibility initially increased, and then decreased. Overall, Moderate oxidation and moderate acid-heating enhanced the stability as well as rheological properties of CE-HIPPEs, thus improving the stability and bioaccessibility of CE. This study offered a new insight into the delivery of bioactive substances by protein fibril aggregates-based HIPPEs.
Sujet(s)
Émulsions , Oryza , Oxydoréduction , Taille de particule , Bêtacarotène , Bêtacarotène/composition chimique , Oryza/composition chimique , Biodisponibilité , Protéines végétales/composition chimique , Viscosité , MalonaldéhydeRÉSUMÉ
This study investigated spray drying a method for microencapsulating Lacticaseibacillus rhamnosus GG using a gastrointestinal resistant composite matrix. An encapsulate composite matrix comprising green banana flour (GBF) blended with maltodextrin (MD) and gum arabic (GA). The morphology of resulted microcapsules revealed a near-spherical shape with slight dents and no surface cracks. Encapsulation efficiency and product yield varied significantly among the spray-dried microencapsulated probiotic powder samples (SMPPs). The formulation with the highest GBF concentration (FIV) exhibited maximum post-drying L. rhamnosus GG viability (12.57 ± 0.03 CFU/g) and best survivability during simulated gastrointestinal digestion (9.37 ± 0.05 CFU/g). Additionally, glass transition temperature (Tg) analysis indicated good thermal stability of SMPPs (69.3 - 92.9 â), while Fourier Transform infrared (FTIR) spectroscopy confirmed the structural integrity of functional groups within microcapsules. The SMPPs characterization also revealed significant variation in moisture content, water activity, viscosity, and particle size. Moreover, SMPPs exhibited differences in total phenolic and flavonoid, along with antioxidant activity and color values throughout the study. These results suggested that increasing GBF concentration within the encapsulating matrix, while reducing the amount of other composite materials, may offer enhanced protection to L. rhamnosus GG during simulated gastrointestinal conditions, likely due to the gastrointestinal resistance properties of GBF.
Sujet(s)
Préparation de médicament , Gomme arabique , Lacticaseibacillus rhamnosus , Musa , Polyosides , Poudres , Probiotiques , Séchage par pulvérisation , Lacticaseibacillus rhamnosus/composition chimique , Gomme arabique/composition chimique , Polyosides/composition chimique , Musa/composition chimique , Taille de particule , Capsules , Farine/analyse , Spectroscopie infrarouge à transformée de Fourier , Digestion , Viscosité , Tube digestif/métabolisme , Viabilité microbienneRÉSUMÉ
The natural dual nanofibril system consisting of the rigid semicrystalline nanofibrils disintegrated from citrus fiber (CF) and soft semiflexible nanofibrils self-assembled from glycyrrhizic acid (GA) has been recently shown to be effective structural building blocks for fabrication of emulsion gels. In this work, the effect of the CF nanofibrils prepared by different mechanical disintegration approaches (i.e., high-pressure microfluidization and hydrodynamic cavitation) on the interfibrillar CF-GA interactions and the subsequent formation and properties of emulsion gels were investigated, with the aim of evaluating the potential of the dual nanofibril-stabilized emulsion gels as templates for synthesizing all-natural edible oleogels. The obtained results demonstrate that compared to the cavitation, the high-pressure microfluidization is more capable of generating CF nanofibrils with a higher degree of nanofibrillation and individualization, thus forming a denser CF-GA gel network with higher viscoelasticity and structural stability due to the stronger multiple intrafibrillar and interfibrillar interactions. The emulsion gels stabilized by the dual nanofibril system are demonstrated to be an efficient template to fabricate solid-like oleogels, and the structural properties of the oleogels can be well tuned by the mechanical disintegration of CF and the GA nanofibril concentration. The prepared oleogels possess high oil loading capacity, dense network microstructure, superior rheological and large deformation compression performances, and satisfactory thermal stability, which is attributed to the compact and ordered CF-GA dual nanofibrillar network via multiple hydrogen-bonding interactions in the continuous phase as well as at the droplet surface. This study highlights the unique use of all-natural dual nanofibrils to develop oil structured soft materials for sustainable applications.
Sujet(s)
Citrus , Émulsions , Gels , Acide glycyrrhizique , Nanofibres , Composés chimiques organiques , Émulsions/composition chimique , Acide glycyrrhizique/composition chimique , Citrus/composition chimique , Nanofibres/composition chimique , Composés chimiques organiques/composition chimique , Gels/composition chimique , Rhéologie , ViscositéRÉSUMÉ
Non-digestible oligosaccharides (OS) and allulose have beneficial health properties and could reduce the amount of added sugar in baked goods. In this study allulose and various OS [fructo-oligosaccharides (FOS), galacto-oligosaccharides (GOS), lactosucrose (LOS), isomalto-oligosaccharides (IMO), Promitor 70R (P70R), and xylo-oligosaccharides (XOS)] were added to a wire-cut cookie formulation at concentrations determined to have similar effects on the gelatinization temperature (Tgel) of starch relative to sucrose. Different baking performance attributes of the doughs and cookies were assessed, including: appearance, spread, color, texture, and % moisture loss after baking. The results were correlated to: OS solution and solid properties and OS effects on starch thermal events (gelatinization, pasting, and retrogradation). The Tgel-matching formulation protocol was effective in producing reduced-sugar cookies which had similar appearance, color, and spread attributes compared to the sucrose control; however, cookie texture significantly varied. Cookies containing allulose were the least similar to the control, having darker color, reduced spread, and softer cake-like texture. The only OS cookies that matched the texture of the sucrose control contained LOS, while P70R cookies were the hardest. Cookie texture correlated strongly with the % total moisture loss after baking (r = -0.8763) and was best explained by OS solution viscosity: more viscous OS solutions limited moisture release and resulted in harder cookies. The Tgel of starch also correlated with OS solution viscosity (r = 0.7861) and should be accounted for in reduced sugar applications. The OS recommended as sucrose replacers in cookies based on principal component analysis groupings were: XOS > IMO > LOS > and GOS.
Sujet(s)
Oligosaccharides , Oligosaccharides/composition chimique , Cuisine (activité)/méthodes , Saccharose/composition chimique , Amidon/composition chimique , Couleur , Eau/composition chimique , Fructose/composition chimique , Manipulation des aliments/méthodes , Viscosité , TempératureRÉSUMÉ
Protein emulsion gels, as potential novel application ingredients in the food industry, are very unstable in their formation. However, the incorporation of sour substances (phosphoric acid, lactic acid, acetic acid, malic acid, glutamic acid, tartaric acid and citric acid) would potentially contribute to the stable formation of whey protein isolate (WPI) emulsion as well as its gel. Thus, in this work, physical stability of seven acid-treated WPI emulsions, and microstructures, rheological properties, water distribution of its emulsion gels were characterized and compared. Initially, the absolute zeta-potential, interfacial protein adsorption, and emulsifying characteristics of acid-induced WPI emulsions were higher in contrast to acid-untreated WPI emulsions. Moreover, acid-induced WPI emulsions were thermally induced (95 â, 30 min) to form its emulsion gel networks via disulfide bonds as the main force (acid-untreated WPI emulsions were unable to form gels). High-resolution microscopic observation revealed that acid-induced WPI in emulsion gel network showed the morphology of aggregates. Dynamic oscillatory rheology results indicated that acid-induced emulsion gel exhibited highly elastic behavior and its viscoelasticity was associated with the generation of protein gel networks and aggregates. In addition, PCA and heatmap results further illustrated that malic acid-induced WPI emulsion gels had the best water holding capacity and gel characteristics. Therefore, this study could provide an effective way for the foodstuffs industry to open up new texture and healthy emulsion gels as fat replaces and loading systems of bioactive substances.
Sujet(s)
Émulsions , Gels , Température élevée , Rhéologie , Protéines de lactosérum , Protéines de lactosérum/composition chimique , Émulsions/composition chimique , Gels/composition chimique , ViscositéRÉSUMÉ
Large groups of active cilia collectively beat in a fluid medium as metachronal waves, essential for some microorganisms motility and for flow generation in mucociliary clearance. Several models can predict the emergence of metachronal waves, but what controls the properties of metachronal waves is still unclear. Here, we numerically investigate the respective impacts of active beating and viscous dissipation on the properties of metachronal waves in a collection of oscillators, using a simple model for cilia in the presence of noise on regular lattices in one and two dimensions. We characterize the wave using spatial correlation and the frequency of collective beating. Our results clearly show that the viscosity of the fluid medium does not affect the wavelength; the activity of the cilia does. These numerical results are supported by a dimensional analysis, which shows that the result of wavelength invariance is robust against the model taken for sustained beating and the structure of hydrodynamic coupling. Interestingly, the enhancement of cilia activity increases the wavelength and decreases the beating frequency, keeping the wave velocity almost unchanged. These results might have significance in understanding paramecium locomotion and mucociliary clearance diseases.
Sujet(s)
Cils vibratiles , Hydrodynamique , Modèles biologiques , Cils vibratiles/physiologie , ViscositéRÉSUMÉ
The aim of this study was to investigate the modification of mechanical, rheological, and sensory properties of chickpea pastes and gels by incorporating other ingredients (olive oil or quinoa flour), to develop plant-based alternatives that meet consumer demands for healthy, natural, and enjoyable food products. The pastes and gels were made with different amounts of chickpea flour (9% and 12%, respectively). For each product, a first set of products with different oil content and a second set with quinoa flour (either added or replaced) were produced. The viscoelastic properties of the pastes and the mechanical properties of the gels were measured. Sensory evaluation and preference assessment were carried out with 100 participants using ranking tests. The study found remarkable differences in rheological, mechanical, and sensory properties of chickpea products upon the inclusion of oil and quinoa flour. The addition of oil increased the viscosity and decreased the elastic contribution to the viscoelasticity of the pastes, while it improved the firmness and plasticity in gels. It also increased the creaminess and preference of both pastes and gels. Replacing chickpea with quinoa flour resulted in less viscous pastes and gels with less firmness and more plasticity. In terms of sensory properties, the use of quinoa as a replacement ingredient resulted in less lumpiness in the chickpea paste and less consistency and more creaminess in both the pastes and gels, which had a positive effect on preference. The addition of quinoa increased the viscosity of pastes and the firmness and stiffness of gels. It increased the consistency and creaminess of both pastes and gels. Quinoa flour and/or olive oil are suitable ingredients in the formulation of chickpea-based products. They contribute to the structure of the system, providing different textural properties that improve acceptance.
Sujet(s)
Chenopodium quinoa , Cicer , Farine , Gels , Rhéologie , Cicer/composition chimique , Chenopodium quinoa/composition chimique , Viscosité , Humains , Gels/composition chimique , Farine/analyse , Goût , Huile d'olive/composition chimique , Manipulation des aliments/méthodes , Adulte , Élasticité , Femelle , MâleRÉSUMÉ
Beta-tricalcium phosphate (ß-TCP) scaffolds manufactured through the foam replication method are widely employed in bone tissue regeneration. The mechanical strength of these scaffolds is a significant challenge, partly due to the rheological properties of the original suspension. Various strategies have been explored to enhance the mechanical properties. In this research, ß-TCP scaffolds containing varying concentrations (0.25-1.00 wt%) of multi-walled carbon nanotubes (MWCNT) were developed. The findings indicate that the addition of MWCNTs led to a concentration-dependent improvement in the viscosity of ß-TCP suspensions. All the prepared slurries exhibited viscoelastic behavior, with the storage modulus surpassing the loss modulus. The three time interval tests revealed that MWCNT-incorporated ß-TCP suspensions exhibited faster structural recovery compared to pure ß-TCP slurries. Introducing MWCNT modified compressive strength, and the optimal improvement was obtained using 0.75 wt% MWCNT. The in vitro degradation of ß-TCP was also reduced by incorporating MWCNT. While the inclusion of carbon nanotubes had a marginal negative impact on the viability and attachment of MC3T3-E1 cells, the number of viable cells remained above 70% of the control group. Additionally, the results demonstrated that the scaffold increased the expression level of osteocalcin, osteoponthin, and alkaline phosphatase genes of adiposed-derived stem cells; however, higher levels of gene expersion were obtained by using MWCNT. The suitability of MWCNT-modified ß-TCP suspensions for the foam replication method can be assessed by evaluating their rheological behavior, aiding in determining the critical additive concentration necessary for a successful coating process.