RESUMEN
The introduction of biocompatible coatings onto nanoparticle surfaces can be synthetically challenging. In this work, calcium phosphate (brushite, CaHPO4â 2H2O), iron oxide (hematite, α-Fe2O3), zinc oxide (ZnO), and CaHPO4@ZnO and α-Fe2O3@ZnO nanoparticles were synthesized and treated with the biocompatible, biodegradable, polysaccharide inulin {(2R,3S,4S,5R)-2-[[(2R,3S,4S,5R)-3,4-dihydroxy-2,5-bis(hydroxymethyl)oxolan-2-yl]oxymethyl]-5-(hydroxymethyl)oxolane-2,3,4-triol} under mild conditions. The products were fully characterized by Fourier transforms infrared (FTIR) spectroscopy, energy dispersive spectroscopy (EDS), dynamic light scattering (DLS), differential thermogravimetric/differential thermal analysis (TGA/DTA), transmission electron microscopy (TEM) and powder X-ray diffraction (XRD). Surface interactions among hematite and brushite with inulin are weak, but coating the nanoparticle surface with ZnO increased the affinity toward the polysaccharide. Inulin adsorption on the nanoparticle surface was confirmed by thermal and spectroscopic analyses. The nanoparticles had diameters ranging from 50 to 80nm, with nearly spherical morphology. The nanoparticles sizes, stability and solubility in water could make them useful as components for enriched foods.
Asunto(s)
Fosfatos de Calcio/química , Materiales Biocompatibles Revestidos/química , Compuestos Férricos/química , Inulina/química , Nanopartículas del Metal/química , Óxido de Zinc/química , Animales , Materiales Biocompatibles , Alimentos Fortificados , Humanos , Luz , Microscopía Electrónica de Transmisión , Nanopartículas/química , Nanotecnología , Tamaño de la Partícula , Polisacáridos/química , Unión Proteica , Dispersión de Radiación , Espectrofotometría , Espectroscopía Infrarroja por Transformada de Fourier , Propiedades de Superficie , Temperatura , Termogravimetría , Agua/química , Difracción de Rayos XRESUMEN
This article reviews rheological properties of milk, concentrated milk, cream, butter, ice cream, and yogurt, as well as the structure and some physicochemical properties of milk components. A brief description of basic rheological concepts related to liquids, solids, and viscoelasticity is presented, including those rheological models commonly used to characterize dairy products. Rheological behaviors exhibited by these dairy products, including Newtonian in milk and concentrated milk, nonNewtonian in concentrated milk, cream, and yogurt, thixotropy revealed by concentrated milk, cream, and yogurt, and the viscoelastic characteristics displayed by butter, ice cream, and yogurt, are analyzed, and relevant process variables affecting the rheological behavior of dairy products are discussed. Also, to facilitate the comparison of test methods and identify the typical instrumentation and models utilized in rheological characterization of dairy products, experimental conditions and equations used for modeling are included in a tabulated form.
