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1.
Opt Lett ; 49(7): 1725-1728, 2024 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-38560847

RESUMO

Ultrasound coupling is one of the critical challenges for traditional photoacoustic (or optoacoustic) microscopy (PAM) techniques transferred to the clinical examination of chronic wounds and open tissues. A promising alternative potential solution for breaking the limitation of ultrasound coupling in PAM is photoacoustic remote sensing (PARS), which implements all-optical non-interferometric photoacoustic measurements. Functional imaging of PARS microscopy was demonstrated from the aspects of histopathology and oxygen metabolism, while its performance in hemodynamic quantification remains unexplored. In this Letter, we present an all-optical thermal-tagging flowmetry approach for PARS microscopy and demonstrate it with comprehensive mathematical modeling and ex vivo and in vivo experimental validations. Experimental results demonstrated that the detectable range of the blood flow rate was from 0 to 12 mm/s with a high accuracy (measurement error:±1.2%) at 10-kHz laser pulse repetition rate. The proposed all-optical thermal-tagging flowmetry offers an effective alternative approach for PARS microscopy realizing non-contact dye-free hemodynamic imaging.


Assuntos
Técnicas Fotoacústicas , Tecnologia de Sensoriamento Remoto , Técnicas Fotoacústicas/métodos , Reologia/métodos , Ultrassonografia/métodos , Microscopia/métodos
2.
Opt Lett ; 49(7): 1741-1744, 2024 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-38560851

RESUMO

Speckle-correlation optical scattering imaging (SCOSI) has shown the potential for non-invasive biomedical diagnostic applications, which directly utilizes the scattering patterns to reconstruct the deep and non-line-of-sight objects. However, the course of the translation of this technique to preclinical biomedical imaging applications has been postponed by the following two facts: 1) the field of view of SCOSI was significantly limited by the optical memory effect, and 2) the molecular-tagged functional imaging of the biological tissues remains largely unexplored. In this work, a proof-of-concept design of the first-generation widefield functional SCOSI (WF-SCOSI) system was presented for simultaneously achieving mesoscopic mapping of fluid morphology and flow rate, which was realized by implementing the concepts of scanning synthesis and fluorescence scattering flowmetry. The ex vivo imaging results of the fluorescence-labeled large-scale blood vessel network phantom underneath the strong scatters demonstrated the effectiveness of WF-SCOSI toward non-invasive hemodynamic imaging applications.


Assuntos
Diagnóstico por Imagem , Hemodinâmica , Imagens de Fantasmas , Reologia , Desenho de Equipamento , Imagem Óptica/métodos
3.
Biofabrication ; 16(3)2024 Apr 11.
Artigo em Inglês | MEDLINE | ID: mdl-38565131

RESUMO

Extrusion-based bioprinting is a promising technology for the fabrication of complex three-dimensional (3D) tissue-engineered constructs. To further improve the printing accuracy and provide mechanical support during the printing process, hydrogel-based support bath materials have been developed. However, the gel structure of some support bath materials can be compromised when exposed to certain bioink crosslinking cues, hence their compatibility with bioinks can be limited. In this study, a xanthan gum-based composite support material compatible with multiple crosslinking mechanisms is developed. Different support bath materials can have different underlying polymeric structures, for example, particulate suspensions and polymer solution with varying supramolecular structure) and these properties are governed by a variety of different intermolecular interactions. However, common rheological behavior can be expected because they have similar demonstrated performance and functionality. To provide a detailed exploration/identification of the common rheological properties expressed by different support bath materials from a unified perspective, benchmark support bath materials from previous studies were prepared. A comparative rheological study revealed both the structural and shear behavior characteristics shared by support bath materials, including yield stress, gel complex moduli, shear-thinning behavior, and self-healing properties. Gel structural stability and functionality of support materials were tested in the presence of various crosslinking stimuli, confirming the versatility of the xanthan-based support material. We further investigated the effect of support materials and the diameter of extrusion needles on the printability of bioinks to demonstrate the improvement in bioink printability and structural integrity. Cytotoxicity and cell encapsulation viability tests were carried out to confirm the cell compatibility of the xanthan gum-based support bath material. We propose and demonstrate the versatility and compatibility of the novel support bath material and provide detailed new insight into the essential properties and behavior of these materials that serve as a guide for further development of support bath-based 3D bioprinting.


Assuntos
Bioimpressão , Engenharia Tecidual , Polissacarídeos Bacterianos , Reologia , Impressão Tridimensional , Bioimpressão/métodos , Hidrogéis/química , Tecidos Suporte/química
4.
Zhongguo Zhong Yao Za Zhi ; 49(3): 634-643, 2024 Feb.
Artigo em Chinês | MEDLINE | ID: mdl-38621867

RESUMO

This paper aims to study the correlation between the physicochemical properties of raw materials and intermediates and the molding quality and law of traditional Chinese medicine(TCM) gel plaster by using TCM slices and powder as raw materials. 48 TCM compounds are selected as model prescriptions to prepare gel plasters. The rotational rheometer is used to determine the rheological parameters of the plaster, including storage modulus(G'), loss modulus(G″), yield stress(τ), and creep compliance [J(t)]. The molding quality of the prepared TCM gel plaster is evaluated by subjective and objective measures. Clustering and principal component analysis are conducted to evaluate the physical properties of the plaster. By measuring the rheological properties of the plaster, the molding quality of the TCM gel plaster can be predicted, with an accuracy of 83.72% after seven days of modeling and 88.37% after 30 days of modeling. When the parameters such as G' and G″ of the plaster are large, and the [J(t)] is small, the molding quality of the plaster is better. When the plaster coating point is no less than 3, it is difficult to be coated. In addition, when the proportion of metal ions in the prescription is higher, the 30-day forming quality of the plaster is mainly affected, and the viscosity of the plaster is poor. If the prescription contains many acidic chemical components, the 7-day forming quality of the plaster is mainly affected, with many residuals. The results suggest that the rheological properties of the plaster can be used to predict the molding quality of TCM slice and powder gel plaster. It can provide a reference for the development of TCM gel plaster prescriptions.


Assuntos
Medicina Tradicional Chinesa , Prescrições , Pós , Viscosidade , Reologia
5.
Sensors (Basel) ; 24(7)2024 Mar 22.
Artigo em Inglês | MEDLINE | ID: mdl-38610233

RESUMO

Increased incidence of traumatic brain injury (TBI) imposes a growing need to understand the pathology of brain trauma. A correlation between the incidence of multiple brain traumas and rates of behavioural and cognitive deficiencies has been identified amongst people that experienced multiple TBI events. Mechanically, repetitive TBIs may affect brain tissue in a similar way to cyclic loading. Hence, the potential susceptibility of brain tissue to mechanical fatigue is of interest. Although temporal changes in ovine brain tissue viscoelasticity and biological fatigue of other tissues such as tendons and arteries have been investigated, no methodology currently exists to cyclically load ex vivo brain tissue. A novel rheology-based approach found a consistent, initial stiffening response of the brain tissue before a notable softening when subjected to a subsequential cyclic rotational shear. History dependence of the mechanical properties of brain tissue indicates susceptibility to mechanical fatigue. Results from this investigation increase understanding of the fatigue properties of brain tissue and could be used to strengthen therapy and prevention of TBI, or computational models of repetitive head injuries.


Assuntos
Lesões Encefálicas Traumáticas , Vibração , Ovinos , Animais , Humanos , Modalidades de Fisioterapia , Encéfalo , Reologia
6.
Soft Matter ; 20(16): 3464-3472, 2024 Apr 24.
Artigo em Inglês | MEDLINE | ID: mdl-38573072

RESUMO

Pancreatic ß-cells regulate glucose homeostasis through glucose-stimulated insulin secretion, which is hindered in type-2 diabetes. Transport of the insulin vesicles is expected to be affected by changes in the viscoelastic and transport properties of the cytoplasm. These are evaluated in situ through particle-tracking measurements using a rat insulinoma ß-cell line. The use of inert probes assists in decoupling the material properties of the cytoplasm from the active transport through cellular processes. The effect of glucose-stimulated insulin secretion is examined, and the subsequent remodeling of the cytoskeleton, at constant effects of cell activity, is shown to result in reduced mobility of the tracer particles. Induction of diabetic-like conditions is identified to alter the mean-squared displacement of the passive particles in the cytoplasm and diminish its reaction to glucose stimulation.


Assuntos
Células Secretoras de Insulina , Insulina , Células Secretoras de Insulina/metabolismo , Animais , Ratos , Insulina/metabolismo , Glucose/metabolismo , Reologia , Secreção de Insulina , Linhagem Celular Tumoral , Diabetes Mellitus Tipo 2/metabolismo
7.
Ultrason Sonochem ; 105: 106868, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38581798

RESUMO

The use of extracts rich in bioactive compounds is becoming increasingly common in the food, cosmetics, and pharmaceutical industries for the production of functional products. Araticum is a potential fruit to be analyzed due to its content of phenolic compounds, carotenoids and vitamins, with antioxidant properties. Therefore, this study aimed to investigate the effect of ultrasound on total phenolic compounds, total carotenoids, ascorbic acid, color, turbidity and rheology in araticum juice. Response surface methodology based on a central composite design was applied. Araticum juice was subjected to sonication at amplitude levels ranging from 20 to 100 % of the total power (400 W) at a constant frequency of 20 kHz for different durations (2 to 10 min). Morphological analysis was conducted to observe microscopic particles, and viscosity and suitability to rheological models (Newtonian, Power Law, and Herschel-Bulkley) were assessed. The ultrasonic probe extraction method was compared to the control juice. According to the responses, using the desirability function, the optimal conditions for extraction were determined to be low power (low amplitude) applied in a short period of time or low power applied in a prolonged time. These conditions allowed an ultrasonic probe to act on releasing bioactive compounds without degrading them. All three rheological models were suitable, with the Power Law model being the most appropriate, exhibiting non-Newtonian pseudoplastic behavior.


Assuntos
Reologia , Annona/química , Sucos de Frutas e Vegetais/análise , Carotenoides/química , Viscosidade , Ondas Ultrassônicas , Sonicação , Fenóis/química , Ácido Ascórbico/química
8.
Soft Matter ; 20(16): 3483-3498, 2024 Apr 24.
Artigo em Inglês | MEDLINE | ID: mdl-38587658

RESUMO

A breast-cancer tumor develops within a stroma, a tissue where a complex extracellular matrix surrounds cells, mediating the cancer progression through biomechanical and -chemical cues. Current materials partially mimic the stromal matrix in 3D cell cultures but methods for measuring the mechanical properties of the matrix at cell-relevant-length scales and stromal-stiffness levels are lacking. Here, to address this gap, we developed a characterization approach that employs probe-based microrheometry and Bayesian modeling to quantify length-scale-dependent mechanics and mechanical heterogeneity as in the stromal matrix. We examined the interpenetrating network (IPN) composed of alginate scaffolds (for adjusting mechanics) and type-1 collagen (a stromal-matrix constituent). We analyzed viscoelasticity: absolute-shear moduli (stiffness/elasticity) and phase angles (viscous and elastic characteristics). We determined the relationship between microrheometry and rheometry information. Microrheometry reveals lower stiffness at cell-relevant scales, compared to macroscale rheometry, with dependency on the length scale (10 to 100 µm). These data show increasing IPN stiffness with crosslinking until saturation (≃15 mM of Ca2+). Furthermore, we report that IPN stiffness can be adjusted by modulating collagen concentration and interconnectivity (by polymerization temperature). The IPNs are heterogeneous structurally (in SEM) and mechanically. Interestingly, increased alginate crosslinking changes IPN heterogeneity in stiffness but not in phase angle, until the saturation. In contrast, such changes are undetectable in alginate scaffolds. Our nonlinear viscoelasticity analysis at tumor-cell-exerted strains shows that only the softer IPNs stiffen with strain, like the stromal-collagen constituent. In summary, our approach can quantify the stromal-matrix-related viscoelasticity and is likely applicable to other materials in 3D culture.


Assuntos
Alginatos , Matriz Extracelular , Matriz Extracelular/química , Matriz Extracelular/metabolismo , Humanos , Alginatos/química , Técnicas de Cultura de Células em Três Dimensões , Viscosidade , Células Estromais/citologia , Células Estromais/metabolismo , Elasticidade , Tecidos Suporte/química , Colágeno Tipo I/química , Colágeno Tipo I/metabolismo , Fenômenos Biomecânicos , Reologia , Modelos Biológicos , Teorema de Bayes
9.
Int J Biol Macromol ; 265(Pt 2): 131159, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38565484

RESUMO

A goal of this study is to explore the difference in rheological properties of xanthan gum (XG)-based mixtures with gum arabic (GA) or GA-based emulsion (GAE). The stability of GAE was improved by thickening with XG. The intrinsic viscosity of all mixtures decreased as GA concentration increased, implying an XG conformational transition from the disordered to the ordered form. All mixtures except for an XG-GA mixture at 6.0 % GA attained a higher consistency index value than XG alone, indicating synergistic interactions between the components. At a high GA concentration (>3.0 %), the XG-GAE mixture showed higher relative apparent viscosity values than the XG-GA mixture. All mixtures except for an XG-GA mixture at 6.0 % GA showed higher elastic modulus and lower viscous modulus values than XG alone. Consequently, all mixtures showed lower tan δ values (0.26-0.30) than XG alone (0.31). Moreover, with a high GA concentration (>1.5 %), the XG-GAE mixtures achieved lower relative tan δ values than XG-GA mixture. These results indicate that XG formed a higher weak gel-like network with GAE than GA. Overall, the findings demonstrate that the interaction between XG and GA is influenced by conformational changes in the latter in both aqueous and emulsion systems.


Assuntos
Goma Arábica , Gomas Vegetais , Emulsões , Polissacarídeos Bacterianos , Viscosidade , Reologia/métodos
10.
Lasers Med Sci ; 39(1): 112, 2024 Apr 24.
Artigo em Inglês | MEDLINE | ID: mdl-38656634

RESUMO

PURPOSE: To measure the dynamic characteristics of the flow field in a complex root canal model activated by two laser-activated irrigation (LAI) modalities at different activation energy outputs: photon-induced photoacoustic streaming (PIPS) and microshort pulse (MSP). METHODS: A phase-locked micro-scale Particle Image Velocimetry (µPIV) system was employed to characterise the temporal variations of LAI-induced velocity fields in the root canal following a single laser pulse. The wall shear stress (WSS) in the lateral root canal was subsequently estimated from the phase-averaged velocity fields. RESULTS: Both PIPS and MSP were able to generate the 'breath mode' of the irrigant current under all tested conditions. The transient irrigation flush in the root canal peaked at speeds close to 6 m/s. However, this intense flushing effect persisted for only about 2000 µs (or 3% of a single laser-pulse activation cycle). For MSP, the maximum WSS magnitude was approximately 3.08 Pa at an activation energy of E = 20 mJ/pulse, rising to 9.01 Pa at E = 50 mJ/pulse. In comparison, PIPS elevated the WSS to 10.63 Pa at E = 20 mJ/pulse. CONCLUSION: Elevating the activation energy can boost the peak flushing velocity and the maximum WSS, thereby enhancing irrigation efficiency. Given the same activation energy, PIPS outperforms MSP. Additionally, increasing the activation frequency may be an effective strategy to improve irrigation performance further.


Assuntos
Reologia , Humanos , Cavidade Pulpar/efeitos da radiação , Irrigação Terapêutica/métodos , Irrigação Terapêutica/instrumentação , Lasers , Irrigantes do Canal Radicular , Técnicas Fotoacústicas/métodos , Preparo de Canal Radicular/métodos , Preparo de Canal Radicular/instrumentação
11.
Med Eng Phys ; 126: 104144, 2024 04.
Artigo em Inglês | MEDLINE | ID: mdl-38621846

RESUMO

The present study adopts a smartphone-based approach for the experimental characterization of coronary flows. Technically, Particle Tracking Velocimetry (PTV) measurements were performed using a smartphone camera and a low-power continuous wave laser in realistic healthy and stenosed phantoms of left anterior descending artery with inflow Reynolds numbers approximately ranging from 20 to 200. A Lagrangian-Eulerian mapping was performed to convert Lagrangian PTV velocity data to a Eulerian grid. Eulerian velocity and vorticity data obtained from smartphone-based PTV measurements were compared with Particle Image Velocimetry (PIV) measurements performed with a smartphone-based setup and with a conventional setup based on a high-power double-pulsed laser and a CMOS camera. Smartphone-based PTV and PIV velocity flow fields substantially agreed with conventional PIV measurements, with the former characterized by lower average percentage differences than the latter. Discrepancies emerged at high flow regimes, especially at the stenosis throat, due to particle image blur generated by smartphone camera shutter speed and image acquisition frequency. In conclusion, the present findings demonstrate the feasibility of PTV measurements using a smartphone camera and a low-power light source for the in vitro characterization of cardiovascular flows for research, industrial and educational purposes, with advantages in terms of costs, safety and usability.


Assuntos
Fenômenos Fisiológicos Cardiovasculares , Smartphone , Reologia/métodos , Velocidade do Fluxo Sanguíneo , Imagens de Fantasmas
12.
Food Res Int ; 185: 114289, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38658073

RESUMO

A food adhesive comprising tannic acid (TA) and soybean protein isolate (SPI) was developed to establish a cohesive bond between soy protein gel and simulated fat. The impact of varying TA concentrations and pH levels on the adhesive's rheology, thermal stability, chemical structure, and tensile strength were investigated. Rheological results revealed a gradual decrease in adhesive viscosity with increasing TA content. Differential scanning calorimetry (DSC) and thermal gravimetric (TG) results indicated that the stability of the adhesive improved with higher TA concentrations, reaching its peak at 0.50% TA addition. The incorporation of TA resulted in the cross-linking of amino group in unfolded SPI molecules, forming a mesh structure. However, under alkaline conditions (pH 9), adhesive viscosity and stability increased compared to the original pH. This shift was due to the disruption of the SPI colloidal charge structure, an increase in the stretching of functional groups, further unfolding of the structure, and an enhanced binding of SPI to TA. Under the initial pH conditions, SPI reacted with TA's active site to form covalent crosslinked networks and hydrogen bonds. In alkaline condition, beyond hydrogen and ionic bonding, the catechol structure was oxidized, forming an ortho-quinone that crosslinked SPI and created a denser structure. Tensile strength measurements and freeze-thaw experiments revealed that the adhesive exhibited maximum tensile strength and optimal adhesion with 0.75% TA at pH 9, providing the best overall performance. This study provides a new formulation and approach for developing plant-based meat analogues adhesives.


Assuntos
Polifenóis , Reologia , Proteínas de Soja , Taninos , Resistência à Tração , Taninos/química , Proteínas de Soja/química , Concentração de Íons de Hidrogênio , Viscosidade , Adesivos/química , 60450
13.
Carbohydr Polym ; 334: 122041, 2024 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-38553238

RESUMO

Recently, there has been a focus on using biopolymer-based particles to stabilize high internal phase Pickering emulsions (HIPPEs) due to the notable advances in biocompatibility and biodegradability. In this work, the complex particles of peanut protein isolate and carboxymethyl cellulose (CMC) with various substitution degrees (DS; 0.7 and 0.9) and weight average molecular weights (Mw; 90, 250, and 700 kDa) were prepared and characterized as novel stabilizers. For the obtained four types of morphologically distinct particles, the complex particles formed by CMC (0.9 DS and 250 kDa) showed cluster structures with an average size of 1.271 µm, equally biphasic wettability with three-phase contact angles of 91.5°, and the highest diffusion rate at the oil-water interface. HIPPEs stabilized by these particles exhibited more elastic behavior due to the smaller tanδ and higher viscosity, as well as excellent thixotropic recovery properties and stability against heating, storage, and freeze-thawing. Furthermore, confocal laser scanning microscopy verified that these particles formed a dense interfacial layer around the oil droplets, which could resist flocculation and coalescence between oil droplets during in vitro digestion. The improved bioaccessibility of curcumin-loaded HIPPEs made these delivery systems potentially apply in functional foods.


Assuntos
Curcumina , Emulsões/química , Curcumina/química , Carboximetilcelulose Sódica , Molhabilidade , Reologia , Tamanho da Partícula
14.
Food Chem ; 447: 138904, 2024 Jul 30.
Artigo em Inglês | MEDLINE | ID: mdl-38447238

RESUMO

To enhance the gel properties of PSE (pale, soft, and exudative)-like chicken meat protein isolate (PPI), the effect of peanut, corn, soybean, and sunflower oils on the gel properties of PPI emulsion gels was investigated. Vegetable oils improved emulsion stability and gel strength and enhanced viscosity and elasticity. The gel strength of the PPI-sunflower oil emulsion gel increased by 163.30 %. The thermal denaturation temperature and enthalpy values were increased. They decreased the particle size of PPI emulsion (P < 0.05) and changed the three-dimensional network structure of PPI emulsion gels from reticular to sheet with a smooth surface and pore-reduced lamellar. They elevated the content of immobile water PPI emulsion gels, decreased the α-helix and ß-turn, and increased the ß-sheet and random coil. Vegetable oil improved the gel properties of PPI in the following order: sunflower oil > soybean oil > corn oil ≈ peanut oil > control group.


Assuntos
Galinhas , Óleos de Plantas , Animais , Emulsões/química , Proteínas de Carne , Óleo de Girassol , Géis/química , Reologia
15.
Int J Biol Macromol ; 264(Pt 2): 130671, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38458286

RESUMO

In this paper we investigate polyelectrolyte complexes of sodium alginate (Alg) and chitin nanocrystals (ChNC). Formation, stability and transport properties of sunflower oil-in-water emulsions stabilized by ChNC-Alg complex were studied using dynamic light scattering (DLS), laser Doppler electrophoresis, optical microscopy, potentiometric titration, rheology and simulated digestion. It has been established that during emulsions formation, the ChNC-Alg complex is rearranged at the interface and the formation of a two-layer coating of the droplet occurs. Stabilized O/W emulsions are stable during storage, in the pH range 2-9 and centrifugal acceleration up to 2000 RCF. Presence of Ca2+ and Na+ ions in the range up to 150 mM has virtually no effect on the droplet size. Inclusion of 5 wt% Alg in the ChNC-based emulsion stabilizer system leads to a drop in Gibbs adsorption >16 times compared to the ChNC-stabilized emulsion, increase in viscosity and rheopexy index of the systems. We found that chemical properties of colloidal phase surface and rheological properties of emulsions stabilized by ChNC-Alg are mostly dependent on the droplet size, not the type of oil as a result of a comparative study of sunflower oil/liquid paraffin oil. Emulsion drops of an optimized composition are stable in the upper parts of the model gastrointestinal tract system and transport vitamin D3 to the small intestine without significant losses. The bioavailability of vitamin D3 in emulsions stabilized with the ChNC-Alg complex is higher than for emulsions stabilized with ChNC alone.


Assuntos
Quitina , Nanopartículas , Emulsões/química , Quitina/química , Disponibilidade Biológica , Colecalciferol , Óleo de Girassol , Reologia , Tamanho da Partícula , Água/química
16.
Food Chem ; 447: 138986, 2024 Jul 30.
Artigo em Inglês | MEDLINE | ID: mdl-38489875

RESUMO

Germination treatment of highland barley enhances its nutritional value while weakening the starch gel properties. This study aims to enhance the characteristics of germinated highland barley starch (GBS) by exploring the synergistic effects of two alkalis (Na2CO3 and NaHCO3) and guar gum (GG) on GBS gel properties. The combined action of alkalis and GG significantly improved the peak viscosity, setback viscosity, and hardness compared with GG alone. The highest G' and G" reached 998 and 204 Pa at 0.4% Na2CO3 addition, which were increased by nearly 44% and 50%, respectively. Fourier-transform infrared spectral analysis revealed that the alkalis strengthened interaction forces, particularly with intensified absorption peaks at 3200-3700 cm-1 and 1550-1750 cm-1. The Na2CO3 and NaHCO3 reduced the spin-spin relaxation time (T2), resulting in a dense starch gel network. This study contributes to enhancing the market application of GBS and offers innovative insights for modifying other starches.


Assuntos
Hordeum , Mananas , Gomas Vegetais , Amido , Amido/química , Galactanos/química , Viscosidade , Géis/química , Reologia
17.
J Food Sci ; 89(4): 2347-2358, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38488735

RESUMO

Mashed potatoes (MP) are famous as ready-to-eat products due to their excellent taste and texture. Problems such as complex injection occur when MP is used as a 3D printing material. To improve the smoothness of MP loading into a 3D syringe barrel and its 3D extrusion printability, the effects of the protein-polysaccharide hybrid gelator developed with different gelatin-B (GB, 2%, 4%, 6%) and κ-carrageenan (KG, 1%) on the rheology and 3D extrusion printability of MP were studied. The rheological results showed that the MP developed a glass transition temperature by adding the hybrid gelator. Adding 1% KG+6% GB (w/w, dry base) to the hybrid gelator has good shear thinning and self-supporting properties and showed the best geometric accuracy. In the extrusion stage, the yield stress, the consistency index (K), and the flow behavior index (n) of MP were 470.69 Pa, 313.48 Pa·sn, and 0.159, respectively. In the recovery stage, the shear recovery time is 30 s. In the self-supporting stage, the storage modulus and loss modulus are significantly higher than those of other groups and have the strongest mechanical properties. Moreover, water distribution, Fourier transform infrared spectroscopy, X-ray diffraction analysis, and microstructure of printed MP with different hybrid gelators were observed. The addition of hybrid gelators reduced the content of free water in MP. Hybrid gelators did not produce new functional groups in the printed materials and did not change the structure of starch. These results provide new insights for applying protein and polysaccharide hybrid gelators in 3D printing.


Assuntos
Solanum tuberosum , Solanum tuberosum/química , Polissacarídeos , Alimentos , Carragenina , Água , Reologia
18.
Int J Biol Macromol ; 264(Pt 1): 130600, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38442829

RESUMO

We explored the rheological and tribological properties of potato starch agglomerated with a sugar binder (maltodextrin or lactose) at various concentrations by using a fluidized bed granulator. The magnitudes of consistency index and apparent viscosity of agglomerated potato starch (APS) decreased as the binder concentration was increased. Moreover, APS with a sugar binder showed lower viscoelastic moduli and higher tan δ values compared to APS with water as the binder (the control). The gel strength of all agglomerates decreased as the sugar concentration was increased. All samples showed anti-thixotropic behavior, and especially, APS with 20 % lactose showed a small anti-thixotropic area. Utilizing the Arrhenius equation clearly elucidated the effect of temperature on the apparent viscosity of all the samples. Although the maltodextrin concentration had little influence on the activation energy of APS, it increased as the lactose concentration was increased. APS samples with a sugar binder showed greater friction coefficient values compared to the control, with maltodextrin having a significant impact. The findings indicate that the rheological and tribological properties of APS rely on the type and concentration of sugar binder.


Assuntos
Solanum tuberosum , Lactose , Amido , Açúcares , Temperatura , Reologia , Viscosidade
19.
Int J Pharm ; 655: 124070, 2024 Apr 25.
Artigo em Inglês | MEDLINE | ID: mdl-38554740

RESUMO

The importance of ink rheology to the outcome of 3D printing is well recognized. However, rheological properties of printing inks containing drug nanocrystals have not been widely investigated. Therefore, the objective of this study was to establish a correlation between the composition of nanocrystal printing ink, the ink rheology, and the entire printing process. Indomethacin was used as a model poorly soluble drug to produce nanosuspensions with improved solubility properties through particle size reduction. The nanosuspensions were further developed into semisolid extrusion 3D printing inks with varying nanocrystal and poloxamer 407 concentrations. Nanocrystals were found to affect the rheological properties of the printing inks both by being less self-supporting and having higher yielding resistances. During printing, nozzle blockages occurred. Nevertheless, all inks were found to be printable. Finally, the rheological properties of the inks were successfully correlated with various printing and product properties. Overall, these experiments shed new light on the rheological properties of printing inks containing nanocrystals.


Assuntos
Nanopartículas , Poloxâmero , Géis , Excipientes/química , Impressão Tridimensional , Reologia , Tinta
20.
J Texture Stud ; 55(2): e12828, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38486415

RESUMO

Rheological analysis of citrus pectin at pH 3 and 7 elucidates its structural dynamics, revealing distinct behaviors influenced by pH. At pH 3, pectin exhibits shear-thinning, with solvent-independent unified rheological profiles identifying three concentration regimes: 0.5%-1.5%, 2%-3%, and 3.5%-4%. These regimes, alongside Cox-Merz superpositions, outline the semi-dilute (c*) and concentrated (c**) transitions at 1.5%-2% and 3%-3.5%, respectively. Moreover, a Morris equation exponent of 0.65 indicates flexible, mobility-restricted macromolecules. Conversely, at pH 7, increased viscosities and Morris plot linearity for p = .1 suggest rigid chain behavior due to electrostatic repulsion among ionized acidic groups. This rigidity leads to concentration-dependent self-assembly structures that diverge from expected unified rheological profiles, a deviation amplified by heating-cooling cycles. This study clarifies the impact of pH on citrus pectin's rheology and emphasizes the intricate relationship between polymeric chain rigidity, self-assembly, and viscosity. By providing a refined understanding of these mechanisms, our findings contribute to the broader field of polysaccharide research, offering insights critical for developing and optimizing pectin-based applications in various industries.


Assuntos
Citrus , Pectinas , Temperatura Baixa , Reologia
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