The unique properties of resistant starch (RS) have made it applicable in the formulation of a broad range of functional foods. The physicochemical properties of RS play a crucial role in its applications. Recently, flow field-flow fractionation (FlFFF) has attracted increasing interest in the separation and characterization of different categories of RS.
View Article and Find Full Text PDFAsymmetrical flow field-flow fractionation (AF4), a gentle tool for the separation and characterization of particles and macromolecules, has attracted increased interest in recent years owing to its broad dynamic size range and utilization of "open channel" voids in the packing or stationary phase. A steric transition phenomenon in which the sample elution mode change from the normal mode to the steric/hyperlayer mode occurs. Accurate characterization by AF4 requires the absence of steric transition, particularly when the sample has a broad size distribution, because the effect of the combination of different modes is difficult to interpret.
View Article and Find Full Text PDF("Tian Ma" in Chinese) is used as a food and medical ingredient in traditional Chinese medicine. In this study, to enhance the anti-breast cancer activity of polysaccharide (GEP), GEPs were modified via sulfidation (SGEP) and acetylation (AcGEP). The physicochemical properties (such as solubility and substitution degree) and structural information (such as molecular weight and radius of gyration ) of GEP derivatives were determined by Fourier transformed infrared (FTIR) spectroscopy and asymmetrical flow field-flow fractionation (AF4) coupled online with multiangle light scattering (MALS) and differential refractive index (dRI) detectors (AF4-MALS-dRI).
View Article and Find Full Text PDFOxidation is an essential biological process for human life. In this study, low density lipoprotein-Tremella fuciformis polysaccharide (LDL-TFP) complexes were prepared by electrostatic and covalent methods. The effects of preparation method on the structure and antioxidant activity of LDL-TFP complexes were investigated by asymmetrical flow field-flow fractionation (AF4) coupled with ultraviolet-visible (UV/Vis), multiangle light scattering (MALS), and differential refractive index (dRI) detectors.
View Article and Find Full Text PDFIn this study, the starches were isolated from three botanical sources (i.e., rice, sweet potato, and lotus seed).
View Article and Find Full Text PDFStarch occurs naturally in the form of semicrystalline granules, and is composed of two types of carbohydrate molecules, amylose (AM) and amylopectin (AP). Starch granules and starch molecules have sizes in the range of 1-100 μm and 20-250 nm, respectively; these size ranges are among the key factors affecting the functional properties of starch. Asymmetrical flow field-flow fractionation (AF4) is a size-based separation technique.
View Article and Find Full Text PDFTo better understand the structure-function relationship of Gastrodia elata polysaccharides (PGEs), PGEs were extracted by ultrasound-assisted extraction method and the effects of extraction time on the structure and conformation of PGEs were evaluated by asymmetrical flow field-flow fractionation (AF4) coupled online with multiangle light scattering (MALS) and differential refractive index (dRI) detectors (AF4-MALS-dRI). Besides separation, AF4-MALS-dRI can provide more information about PGEs, such as size and molecular weight (M) distributions, apparent density, and conformation. The effects of PGEs on the proliferation, apoptosis, and cell cycle of MCF-7 cells were investigated.
View Article and Find Full Text PDFInsight into the structure and conformation characteristics of starch that influence its enzyme susceptibility is import for its potential application. In this study, the capacity of asymmetrical flow field-flow fractionation (AF4) coupled online with multi-angle light scatting (MALS) and differential refractive index (dRI) detectors (AF4-MALS-dRI) for monitoring of change in structure and conformation of potato starch during enzymatic hydrolysis was evaluated. The dissolution behavior of potato resistant starch (type 2) (PRS) was investigated.
View Article and Find Full Text PDFPolysaccharides are the most abundant natural biopolymers on the earth and are widely used in food, medicine, materials, cosmetics, and other fields. The physicochemical properties of polysaccharides such as particle size and molecular weight often affect their practical applications. In recent years, asymmetrical flow field-flow fractionation (AF4) has been widely used in the separation and characterization of polysaccharides because it has no stationary phases or packing materials, which reduces the risk of shear degradation of polysaccharides.
View Article and Find Full Text PDFRheumatoid arthritis (RA) is a complex chronic inflammatory autoimmune disease. The pathogenesis of the disease is related to invariant natural killer T (iNKT) cells. Patients with active RA present fewer iNKT cells, defective cell function, and excessive polarization of Th1.
View Article and Find Full Text PDFA method based on asymmetrical flow field-flow fractionation (AF4) coupled with a multi-angle light scattering detector and a differential refractive detector was developed for the separation and characterization of millet starch. In this study, the effects of sample loading, cross-flow rate, half-life, and ionic strength and pH value of the carrier liquid on the AF4 analysis of millet starch were investigated. In addition, the molecular structure of millet starch was determined under the optimum conditions.
View Article and Find Full Text PDFStarch is one of the most abundant, renewable, non-toxic, and biodegradable polysaccharides, mainly comprising amylose and amylopectin. The physicochemical properties and structure of starch affect the quality of starch-based products. Therefore, the accurate characterization of the physicochemical properties and structure of starch is important to obtain products that meet specific functions.
View Article and Find Full Text PDFBackground: The therapeutic effect of adoptive infusion of specific thymus-derived invariant natural killer T (iNKT) cells in a mouse model of rheumatoid arthritis (RA) was observed, and the mechanism of cellular immunotherapy was preliminarily explored.
Methods: Thymus-derived iNKT cells were infused to RA model mice, with α-GalCer as a positive control. Then, ankle swelling was examined, as well as inflammatory cell infiltration to the joint tissue (hematoxylin-eosin [H&E] staining).
In this study, the capacity of asymmetrical flow field-flow fractionation (AF4) coupled with multiangle light scattering (MALS) and differential refractive index (dRI) detectors, to monitor starch retrogradation behavior in situ was evaluated. Meanwhile, the starch samples were characterized by differential scanning calorimetry (DSC) and fourier transform infrared spectroscopy (FTIR). The effect of the botanical origin, amylose/amylopectin ratio, storage conditions (i.
View Article and Find Full Text PDFHome-made asymmetrical flow field-flow fractionation (AF4) system, online coupled with ultraviolet/visible (UV/Vis) detector was employed for the separation and size characterization of low density lipoprotein (LDL) in egg yolk plasma. At close to natural condition of egg yolk, the effects of cross flow rate, sample loading, and type of membrane on the size distribution of LDL were investigated. Under the optimal operation conditions, AF4-UV/Vis provides the size distribution of LDL.
View Article and Find Full Text PDFIn this work, the ability of asymmetrical flow field-flow fractionation (AF4) coupled with UV-vis, multiangle light scattering (MALS), and quasi-elastic light scattering (QELS) (AF4-UV-MALS-QELS) for monitoring aggregation of components of egg yolk plasma was evaluated. The effect of external factors (i.e.
View Article and Find Full Text PDFThe capability of asymmetrical flow field-flow fractionation (AF4) coupled with UV/VIS, multiangle light scattering (MALS) and quasi-elastic light scattering (QELS) (AF4-UV-MALS-QELS) for separation and characterization of egg yolk plasma was evaluated. The accuracy of hydrodynamic radius (Rh) obtained from QELS and AF4 theory (using both simplified and full expression of AF4 retention equations) was discussed. The conformation of low density lipoprotein (LDL) and its aggregates in egg yolk plasma was discussed based on the ratio of radius of gyration (Rg) to Rh together with the results from bio-transmission electron microscopy (Bio-TEM).
View Article and Find Full Text PDFIn this study, sedimentation field-flow fractionation (SdFFF) was, for the first time, applied for determination of size distribution of Hβ zeolite particles modified by citric acid (CA-Hβ). Effects of the particle dispersion and the carrier liquid composition (type of dispersing reagent (surfactant) and salt added in the carrier liquid, ionic strength, and pH) on SdFFF elution behavior of CA-Hβ zeolite particles were systematically investigated. Also the SdFFF separation efficiency of the particles was discussed in terms of the forces such as van der Waals, hydrophobic, and induced-dipole interactions.
View Article and Find Full Text PDFIn this study, asymmetrical flow field-flow fractionation (AF4) coupled online with UV, multiangle light scattering (MALS), and fluorescence (FS) detectors (AF4-UV-MALS-FS) was employed for separation and characterization of egg yolk plasma. AF4 provided separation of three major components of the egg yolk plasma i.e.
View Article and Find Full Text PDFAsymmetrical flow field-flow fractionation (AF4) has been considered to be a useful tool for simultaneous separation and characterization of polydisperse macromolecules or colloidal nanoparticles. AF4 analysis requires the knowledge of the channel thickness (w), which is usually measured by injecting a standard with known diffusion coefficient (D) or hydrodynamic diameter (dh). An accurate w determination is a challenge due to its uncertainties arising from the membrane's compressibility, which may vary with experimental condition.
View Article and Find Full Text PDFThe ability of asymmetrical flow field-flow fractionation (AF4) coupled online with multiangle light scattering (MALS) and refractive index detector (RI) (AF4-MALS-RI) for monitoring of change in molecular conformation of wheat and barley starch during germination process was evaluated. AF4 provides separation of starch molecules based on their hydrodynamic sizes, and MALS yields the molar mass and molecular size (radius of gyration, Rg). In vitro and in vivo anti-hyperglycemic effect of germinated wheat and barley was studied.
View Article and Find Full Text PDFIn field-flow fractionation (FFF), there is the 'steric transition' phenomenon where the sample elution mode changes from the normal to steric/hyperlayer mode. Accurate analysis by FFF requires understanding of the steric transition phenomenon, particularly when the sample has a broad size distribution, for which the effect by combination of different modes may become complicated to interpret. In this study, the steric transition phenomenon in asymmetrical flow FFF (AF4) was studied using polystyrene (PS) latex beads.
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