RESUMEN
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.
Asunto(s)
Citrus , Emulsiones , Geles , Ácido Glicirrínico , Nanofibras , Compuestos Orgánicos , Emulsiones/química , Ácido Glicirrínico/química , Citrus/química , Nanofibras/química , Compuestos Orgánicos/química , Geles/química , Reología , ViscosidadRESUMEN
To investigate the quality of different ozone-oxidized surimi gels and their in vitro digestion and absorption characteristics, surimi rinsed with different concentrations of ozonated water (0, 8, 26 mg/L) were prepared. Then, the degree of oxidation and gel structure of surimi were determined, the in vitro digestion and absorption of the gels were simulated, and the digestion and absorption products were analyzed by LC-MS/MS. The results showed that the quality of surimi gels was improved after proper ozone oxidation. After ozone water rinsing, the dry matter digestibility, peptide, and amino acid content increased, and the changes of all three were in line with the Logistic kinetic model (R2 = 0.95-0.99). Caco-2 cell absorption experiments showed that the absorption rate of peptides and amino acids decreased after ozone water rinsing. In summary, ozone oxidation can promote the digestion of surimi gels, but it also reduces the absorption of peptides and amino acids by Caco-2 cells. This study provides a reference for the application of ozone in the food field.
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Carpas , Digestión , Productos Pesqueros , Oxidación-Reducción , Ozono , Ozono/química , Células CACO-2 , Animales , Humanos , Productos Pesqueros/análisis , Carpas/metabolismo , Geles/química , Aminoácidos/metabolismo , Aminoácidos/análisis , Espectrometría de Masas en Tándem , Absorción Intestinal , PéptidosRESUMEN
Pasta filata-style cheese products are among the world's most famous cheese varieties. Thermo-mechanical processing of cheese curd results in stringy, fibrous, and anisotropic structures with pleasing texture attributes. A recent area of research focuses on improving yield during the manufacturing of pasta filata-type cheese products by homogenizing the milk. This process reduces the size of fat droplets, leading to better retention of milk fat during curd plasticization. As this sometimes results in texture deficits, this study aims to investigate the impact of thermo-mechanical processing on curd from homogenized and non-homogenized milk. The hypothesis is that increased thermo-mechanical processing, leading to more anisotropic structural elements, may offset texture deficits caused by homogenization. To assess textural and structural changes due to homogenization and thermo-mechanical processing, mechanical tests including rheology and texture analysis were conducted, along with confocal-laser-scanning microscopy. Additionally, sensory evaluation involving panelists consuming the samples and recording mastication properties such as muscle activity and jaw movement was carried out. Dynamic data modeling was used to derive connections between structure and texture. Results showed that homogenization alone did not yield significant differences between the samples, but plasticization and texturization properties differed significantly. Non-homogenized samples developed a distinct fibrous structure, and muscle activities and jaw movements increased significantly (p < 0.01) with longer thermo-mechanical processing.
Asunto(s)
Caseínas , Queso , Manipulación de Alimentos , Geles , Masticación , Leche , Queso/análisis , Manipulación de Alimentos/métodos , Animales , Masticación/fisiología , Leche/química , Geles/química , Caseínas/química , Reología , Humanos , CalorRESUMEN
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.
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Emulsiones , Geles , Calor , Reología , Proteína de Suero de Leche , Proteína de Suero de Leche/química , Emulsiones/química , Geles/química , ViscosidadRESUMEN
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.
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Chenopodium quinoa , Cicer , Harina , Geles , Reología , Cicer/química , Chenopodium quinoa/química , Viscosidad , Humanos , Geles/química , Harina/análisis , Gusto , Aceite de Oliva/química , Manipulación de Alimentos/métodos , Adulto , Elasticidad , Femenino , MasculinoRESUMEN
This study explores the potential antibacterial applications of zinc oxide nanoparticles (ZnO NPs) enhanced with silver (Ag) using plant gel (ZnO-AgO NPs). The problem addressed is the increasing prevalence of pathogenic bacteria and the need for new, effective antimicrobial agents. ZnO NPs possess distinctive physicochemical properties that enable them to selectively target bacterial cells. Their small size and high surface area-to-volume ratio allow efficient cellular uptake and interaction with bacterial cells. In this study, the average size of the synthesized ZnO-Ag nanoparticles was 77.1 nm, with a significant standard deviation of 33.7 nm, indicating a wide size distribution. The nanoparticles demonstrated remarkable antibacterial efficacy against gram-negative and gram-positive bacteria, with inhibition zones of 14.33 mm for E. coli and 15.66 mm for B. subtilis at a concentration of 300 µg/ml. Minimum inhibitory concentrations (MIC) were determined to be 100 µg/ml for E. coli and 75 µg/ml for S. saprophyticus. Additionally, ZnO-Ag NPs exhibited excellent biocompatibility, making them appropriate for various pharmacological uses. This study utilizes Ferula latisecta gels, offering a sustainable and eco-friendly approach to nanoparticle synthesis. Incorporating of Ag into ZnO NPs significantly enhances their antimicrobial properties, with the combined results showing great inhibition effects on pathogenic microbes. The findings suggest that ZnO-Ag NPs could be a promising candidate for addressing the challenges posed by drug-resistant bacterial infections and enhancing antimicrobial treatments.
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Antibacterianos , Ferula , Bacterias Gramnegativas , Bacterias Grampositivas , Nanopartículas del Metal , Pruebas de Sensibilidad Microbiana , Plata , Óxido de Zinc , Antibacterianos/farmacología , Antibacterianos/química , Antibacterianos/síntesis química , Plata/química , Plata/farmacología , Nanopartículas del Metal/química , Bacterias Grampositivas/efectos de los fármacos , Óxido de Zinc/química , Óxido de Zinc/farmacología , Bacterias Gramnegativas/efectos de los fármacos , Ferula/química , Geles/química , Geles/farmacología , Escherichia coli/efectos de los fármacosRESUMEN
Oat products have gained widespread recognition as a health food due to their rich and balanced nutritional profile and convenience. However, the unique matrix composition of oats, which differs significantly from other cereals, presents specific challenges for mycotoxin analysis. This study presents an ultrahigh-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) method enhanced with an innovative egg white gel pretreatment for the simultaneous analysis of 13 regulated and unregulated trichothecenes in oats. The method demonstrated excellent performance with high accuracy (> 87.5%), repeatability (< 5.7%), and reproducibility (< 8.1%). Analysis of 100 commercial oat products revealed a concerning detection rate (78%) for at least one of the 11 trichothecenes investigated. Notably, deoxynivalenol, exceeding the standard limit in 2% of samples, exhibited the highest detection rate (62%). Additionally, concerning co-occurrence patterns and positive correlations were observed, highlighting potential synergistic effects. The first-time detection of unregulated mycotoxins (T-2 triol, 4,15-diacetoxyscirpenol, 15-acetoxyscirpenol, and neosolaniol) underscores the need for comprehensive monitoring. This method, while developed for oats, shows potential for broader application to other cereals, though further investigation and confirmation are necessary. These findings suggest a potentially underestimated risk of trichothecenes in oats, necessitating continuous monitoring to ensure consumer safety.
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Avena , Contaminación de Alimentos , Límite de Detección , Espectrometría de Masas en Tándem , Tricotecenos , Avena/química , Espectrometría de Masas en Tándem/métodos , Cromatografía Líquida de Alta Presión/métodos , Tricotecenos/análisis , Contaminación de Alimentos/análisis , Geles/química , Reproducibilidad de los ResultadosRESUMEN
Chitosan, alginate, and chitosan-alginate (50:50) mixed hydrogels were prepared by freeze casting, freeze-drying, and subsequent physical cross-linking. Chitosan was cross-linked with citrate and alginate with calcium ions, while the mixed gels were cross-linked with both cross-linking agents. Both cryogels and xerogels were obtained by lyophilization and drying of the hydrogels. We investigated the effect of the chemical composition and the physical state of gels on the gel structure and sorption of model dyes. Alginate and mixed gels cross-linked with Ca2+ ions sorbed 80-95% of cationic dye from the solutions. The chitosan gels are primarily capable of adsorbing anionic dyes, but at near-neutral pH, their capacity is lower than that of alginate gels, showing 50-60% dye sorption. In the case of alginate gels, the dye sorption capacity of xerogels, cryogels, and hydrogels was the same, but for chitosan gels, the hydrogels adsorbed slightly less dye than the dried gels.
Asunto(s)
Alginatos , Quitosano , Hidrogeles , Quitosano/química , Alginatos/química , Adsorción , Hidrogeles/química , Concentración de Iones de Hidrógeno , Sustancias Peligrosas/química , Sustancias Peligrosas/análisis , Geles/química , Colorantes/química , LiofilizaciónRESUMEN
Developing a microenvironment-responsive drug delivery system (DDS) for the gastrointestinal system is of great interest to enhance drug efficiency and minimize side effects. Unfortunately, the rapid-flowing digestive juice in the gastrointestinal tract and the continuous contraction and peristalsis of the gastrointestinal tract muscle accelerate the elimination of drug carriers. In this study, a boric hydroxyl-modified mesoporous Mg(OH)2 drug carrier is prepared to prolong the drug retention time. Results show that the newly designed DDS presents high biocompatibility and can immediately turn the free polyhydric alcohol molecules into a gelation form. The in situ-formed gelation network presents high viscosity and can prevent the drug carriers from being washed away by the digestive juice in the gastrointestinal tract.
Asunto(s)
Portadores de Fármacos , Sistemas de Liberación de Medicamentos , Tracto Gastrointestinal , Geles , Tracto Gastrointestinal/metabolismo , Portadores de Fármacos/química , Sistemas de Liberación de Medicamentos/métodos , Geles/química , Humanos , Viscosidad , AnimalesRESUMEN
In this study, we investigated the use of deep eutectic solvents (DESs) at different molar ratios and temperatures as a green and efficient approach for microfibers (MFs) extraction. Our approach entailed the utilization of Firmiana simplex bark (FSB) fibers, enabling the production of different dimensions of FSB microfibers (FSBMFs) by combining DES pretreatment and mechanical disintegration technique. The proposed practice demonstrates the simplicity and effectiveness of the method. The morphology of the prepared microfibers was studied using the Scanning electron microscopic (SEM) technique. Additionally, the results revealed that the chemical and mechanical treatments did not significantly alter the well-preserved cellulose structure of microfibers, and a crystallinity index of 56.6 % for FSB fibers and 63.8 % for FSBMFs was observed by X-ray diffraction (XRD) analysis. Furthermore, using the freeze-drying technique, FSBMFs in water solutions produced effective aerogels for air purification application. In comparison to commercial mask (CM), FSBMF aerogels' superior hierarchical cellular architectures allowed them to attain excellent filtration efficiencies of 94.48 % (PM10) and 91.51 % (PM2.5) as well as excellent degradation properties were analyzed. The findings show that FSBMFs can be extracted from Firmiana simplex bark, a natural cellulose-rich material, using DES for environmentally friendly aerogel preparation and applications.
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Biomasa , Corteza de la Planta , Corteza de la Planta/química , Disolventes Eutécticos Profundos/química , Celulosa/química , Geles/química , Difracción de Rayos X , Solventes/químicaRESUMEN
In recent years, the utilization of aerogel templates in oleogels to replace animal fats has garnered considerable attention due to health concerns. This study employed a "fiber-particle core-shell nanostructure model" to combine sodium carboxymethylcellulose (CMCNa) and soy protein isolate (SPI) or SPI hydrolysate (SPIH), and freeze-dried to form aerogel template, which was then dipped into oil to induce oleogels. The results showed that adding SPIH significantly improved the physicochemical properties of oleogels. The results of ζ-potential, FTIR, and rheology demonstrated a stronger binding of SPIH to CMC-Na compared to SPI. The CMC-Na-SPIH aerogels exhibited a coarser surface and denser network structure in contrast to CMC-Na-SPI aerogels, with an oil holding capacity (OHC) of up to 84.6 % and oil absorption capacity (OAC) of 47.4 g/g. The mechanical strength of oleogels was further enhanced through chemical crosslinking. Both CMC-Na-SPI and CMC-Na-SPIH oleogels displayed excellent elasticity and reversible compressibility, with CMC-Na-SPIH oleogels demonstrating superior mechanical strength. Additionally, CMC-Na-SPIH oleogels exhibited enhanced slow release of antimicrobial substances and antioxidant properties. Increasing the content of SPI/SPIH significantly improved the mechanical strength, antioxidant capacity, and OHC of the oleogels. This research presents a straightforward and promising approach to enhance the performance of aerogel template oleogels.
Asunto(s)
Compuestos Orgánicos , Proteínas de Soja , Proteínas de Soja/química , Compuestos Orgánicos/química , Hidrólisis , Carboximetilcelulosa de Sodio/química , Reología , Reactivos de Enlaces Cruzados/química , Geles/químicaRESUMEN
Sirolimus (SR) is a macrolide with antifungal and antitumor immunosuppressant properties, classified as a selective inhibitor of mammalian target of rapamycin (mTOR). In this study, an ionic in situ gel of SR (SR-SUS-ISG) was formulated using gellan gum, exhibiting stability regardless of temperature and pH variations, causing minimal irritation. Harnessing the physiological conditions of the eye, SR-SUS-ISG underwent gelation upon contact with ions, increasing drug viscosity and prolonging retention on the ocular surface. Concurrently, SR-SUS-ISG displayed favorable shear dilution properties, reducing viscosity at ambient temperature, enhancing fluidity, and facilitating convenient packaging and transport. Biocompatibility assessments on both human corneal epithelial cells and rabbit eyes demonstrated that SR-SUS-ISG could well be tolerated. Pharmacokinetic investigations in rabbit ocular aqueous humor revealed sustained release, improved corneal penetration, and enhanced bioavailability. Additionally, in a rat corneal alkali burn model, SR-SUS-ISG exhibited inhibitory effects on corneal neovascularization, associated with decreased levels of the inflammatory factors VEGF and MMPs. These findings suggested that SR-SUS-ISG held promise as an effective ocular drug delivery system.
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Geles , Sirolimus , Animales , Conejos , Sirolimus/farmacología , Sirolimus/farmacocinética , Sirolimus/química , Humanos , Geles/química , Córnea/efectos de los fármacos , Córnea/metabolismo , Ratas , Masculino , Polisacáridos Bacterianos/química , Nanopartículas/química , Administración Oftálmica , Neovascularización de la Córnea/tratamiento farmacológico , Ratas Sprague-Dawley , Viscosidad , Sistemas de Liberación de Medicamentos , Soluciones Oftálmicas/química , Soluciones Oftálmicas/farmacología , Línea Celular , Disponibilidad BiológicaRESUMEN
A unique approach is imperative for the development of drugs aimed at inhibiting various stages of infection, rather than solely focusing on bacterial viability. Among the array of unconventional targets explored for formulating novel antimicrobial medications, blocking the quorum-sensing (QS) system emerges as a highly effective and promising strategy against a variety of pathogenic microbes. In this investigation, we have successfully assessed nine α-aminoamides for their anti-QS activity using Agrobacterium tumefaciensNT1 as a biosensor strain. Among these compounds, three (2, 3and, 4) have been identified as potential anti-QS candidates. Molecular docking studies have further reinforced these findings, indicating that these compounds exhibit favorable pharmacokinetic profiles. Additionally, we have assessed the ligand's stability within the protein's binding pocket using molecular dynamics (MD) simulations and MMGBSA analysis. Further, combination of antiquorum sensing properties with antibiotics viaself-assembly represents a promising approach to enhance antibacterial efficacy, overcome resistance, and mitigate the virulence of bacterial pathogens. The release study also reflects a slow and gradual release of the metronidazole at both pH 6.5 and pH 7.4, avoiding the peaks and troughs associated with more immediate release formulations.
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Agrobacterium tumefaciens , Antibacterianos , Metronidazol , Simulación del Acoplamiento Molecular , Simulación de Dinámica Molecular , Percepción de Quorum , Agrobacterium tumefaciens/efectos de los fármacos , Percepción de Quorum/efectos de los fármacos , Metronidazol/farmacología , Metronidazol/química , Antibacterianos/farmacología , Antibacterianos/química , Pruebas de Sensibilidad Microbiana , Geles/química , Sinergismo Farmacológico , Liberación de FármacosRESUMEN
Adopting a non-covalent co-assembly strategy shows great potential in loading drugs efficiently and safely in drug delivery systems. However, finding an efficient method for developing high strength gels with thixotropic characteristics is still challenging. In this work, by hybridizing the low molecular weight gelator fluorenylmethyloxycarbonyl-phenylalanine (Fmoc-F) (first single network, 1st SN) and alginate (second single network, 2nd SN) into a dual network (DN) gel, gels with high strength as well as thixotropy were prepared efficiently. The DN gels showed high strength (103 Pa in SN gels and 105 Pa in DN gels) and thixotropic characteristics (yield strain <25%; recovery ratio >85% within 100 seconds). The application performance was verified by loading doxorubicin (DOX), showing better encapsulation capacity (77.06% in 1st SN, 59.11% in 2nd SN and 96.71% in DN) and sustained release performance (lasting one week under physiological conditions) than single network gels. Experimental and DFT results allowed the elaboration of the specific non-covalent co-assembly mechanism for DN gel formation and DOX loading. The DN gels were formed by co-assembly driven by H-bond and π-π stacking interactions and then strengthened by Ca2+-coupling. Most DOX molecules co-assembled with Fmoc-F and alginate through π-π stacking and H-bond interactions (DOX-I), with a few free DOX molecules (DOX-II) left. Proven by the release dynamics test, DOX was released through a diffusion-erosion process, in an order of DOX-I first and then DOX-II. This work suggests that non-covalent co-assembly is a useful technique for effective material strengthening and drug delivery.
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Alginatos , Doxorrubicina , Liberación de Fármacos , Geles , Doxorrubicina/química , Doxorrubicina/administración & dosificación , Geles/química , Alginatos/química , Preparaciones de Acción Retardada/química , Portadores de Fármacos/química , Fluorenos/química , Fenilalanina/químicaRESUMEN
Gelation of protein condensates formed by liquid-liquid phase separation occurs in a wide range of biological contexts, from the assembly of biomaterials to the formation of fibrillar aggregates, and is therefore of interest for biomedical applications. Soluble-to-gel (sol-gel) transitions are controlled through macroscopic processes such as changes in temperature or buffer composition, resulting in bulk conversion of liquid droplets into microgels within minutes to hours. Using microscopy and mass spectrometry, we show that condensates of an engineered mini-spidroin (NT2repCTYF) undergo a spontaneous sol-gel transition resulting in the loss of exchange of proteins between the soluble and the condensed phase. This feature enables us to specifically trap a silk-domain-tagged target protein in the spidroin microgels. Surprisingly, laser pulses trigger near-instant gelation. By loading the condensates with fluorescent dyes or drugs, we can control the wavelength at which gelation is triggered. Fluorescence microscopy reveals that laser-induced gelation significantly further increases the partitioning of the fluorescent molecules into the condensates. In summary, our findings demonstrate direct control of phase transitions in individual condensates, opening new avenues for functional and structural characterization.
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Rayos Láser , Transición de Fase , Fibroínas/química , Colorantes Fluorescentes/química , Geles/químicaRESUMEN
Proteins are adjustable units from which biomaterials with designed properties can be developed. However, non-native folded states with controlled topologies are hardly accessible in aqueous environments, limiting their prospects as building blocks. Here, we demonstrate the ability of a series of anhydrous deep eutectic solvents (DESs) to precisely control the conformational landscape of proteins. We reveal that systematic variations in the chemical composition of binary and ternary DESs dictate the stabilization of a wide range of conformations, that is, compact globular folds, intermediate folding states, or unfolded chains, as well as controlling their collective behavior. Besides, different conformational states can be visited by simply adjusting the composition of ternary DESs, allowing for the refolding of unfolded states and vice versa. Notably, we show that these intermediates can trigger the formation of supramolecular gels, also known as eutectogels, where their mechanical properties correlate to the folding state of the protein. Given the inherent vulnerability of proteins outside the native fold in aqueous environments, our findings highlight DESs as tailorable solvents capable of stabilizing various non-native conformations on demand through solvent design.
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Geles , Pliegue de Proteína , Proteínas , Solventes , Solventes/química , Proteínas/química , Geles/química , Conformación ProteicaRESUMEN
To facilitate the application of rhamnogalacturonan-I (RG-I)-enriched pectins (RGPs) as novel, healthy, and gelling food additives, this study compared the structural characteristics and gelling properties of RGPs extracted from citrus peel via four methods (alkali: AK, high-temperature/pressure: TP, citric acid: CA, and enzyme-assisted: EA extractions). AK and CA yielded pectins with the highest RG-I proportions (54.8 % and 51.9 %, respectively) by disrupting the homogalacturonan region; TP and EA increased the RG-I proportions by ~10 %. Among the four methods, AK induced the lowest degree of esterification (DE) (6.7 %) and longer side chains that form strong entanglement, contributing to its highest gel hardness. The relatively low DE (18.5 %) of CA RGP facilitated stable gel formation. Notably, its highly branched RG-I region afforded more intramolecular hydrophobic interactions, making a more highly cross-linked gel network of better gel resilience. In contrast, TP induced the highest DE (57 %) and curved molecular chains; it inhibited Ca2+ binding, entanglement, and intramolecular hydrophobic interactions, and thus no gel formed. EA RGP was associated with the lowest molecular size, rendering it more difficult for Ca2+ to form links, which resulted no gel. These findings offer insights into the relationship among the extraction methods, molecular structures, and gelling properties of RGPs.
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Citrus , Geles , Pectinas , Pectinas/química , Pectinas/aislamiento & purificación , Citrus/química , Geles/química , Esterificación , Interacciones Hidrofóbicas e Hidrofílicas , Ácido Cítrico/química , Reología , Frutas/químicaRESUMEN
Rapid, efficient, versatile, easy-to-use, and non-expensive analytical approaches are globally demanded for food analysis. Many ambient ionization approaches based on electrospray ionization (ESI) have been developed recently for the rapid molecular characterization of food products. However, those approaches mainly suffer from insufficient signal duration for comprehensive chemical characterization by tandem MS analysis. Here, a commercially available disposable gel loading tip is used as a low-cost emitter for the direct ionization of untreated food samples. The most important advantages of our approach include high stability, and durability of the signal (> 10 min), low cost (ca. 0.1 USD per run), low sample and solvent consumption, prevention of tip clogging and discharge, operational simplicity, and potential for automation. Quantitative analysis of sulfapyridine, HMF (hydroxymethylfurfural), and chloramphenicol in real sample shows the limit-of-detection 0.1 µg mL-1, 0.005 µg mL-1, 0.01 µg mL-1; the linearity range 0.1-5 µg mL-1, 0.005-0.25 µg mL-1, 0.01-1 µg mL-1; and the linear fits R2 ≥ 0.980, 0.991, 0.986. Moreover, we show that tip-ESI can also afford sequential molecular ionization of untreated viscous samples, which is difficult to achieve by conventional ESI. We conclude that tip-ESI-MS is a versatile analytical approach for the rapid chemical analysis of untreated food samples.
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Análisis de los Alimentos , Límite de Detección , Espectrometría de Masa por Ionización de Electrospray , Espectrometría de Masa por Ionización de Electrospray/métodos , Análisis de los Alimentos/métodos , Geles/química , Cloranfenicol/análisis , Contaminación de Alimentos/análisis , Furaldehído/análisis , Furaldehído/análogos & derivadosRESUMEN
The effects of oil type, emulsifier type, and emulsion particle size on the texture, gel strength, and rheological properties of SPI emulsion-filled gel (SPI-FG) and TFSP emulsion-filled gel (TFSP-FG) were investigated. Using soybean protein isolate or sodium caseinate as emulsifiers, emulsions with cocoa butter replacer (CBR), palm oil (PO), virgin coconut oil (VCO), and canola oil (CO) as oil phases were prepared. These emulsions were filled into SPI and TFSP gel substrates to prepare emulsion-filled gels. Results that the hardness and gel strength of both gels increased with increasing emulsion content when CBR was used as the emulsion oil phase. However, when the other three liquid oils were used as the oil phase, the hardness and gel strength of TFSP-FG decreased with the increasing of emulsion content, but those of SPI-FG increased when SPI was used as emulsifier. Additionally, the hardness and gel strength of both TFSP-FG and SPI-FG increased with the decreasing of mean particle size of emulsions. Rheological measurements were consistent with textural measurements and found that compared with SC, TFSP-FG, and SPI-FG showed higher G' values when SPI was used as emulsifier. Confocal laser scanning microscopy (CLSM) observation showed that the distribution and stability of emulsion droplets in TFSP-FG and SPI-FG were influenced by the oil type, emulsifier type and emulsion particle size. SPI-stabilized emulsion behaved as active fillers in SPI-FG reinforcing the gel matrix; however, the gel matrix of TFSP-FG still had many void pores when SPI-stabilized emulsion was involved. In conclusion, compared to SPI-FG, the emulsion filler effect that could reinforce gel networks became weaker in TFSP-FG.