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Raw eggs were separated into yolks and whites before thermal treatment. An ohmic heating process at 20 kHz and 30 V was used for egg-yolk samples, and color changes were monitored with a computer vision system. Egg-white samples were treated with a water bath, and absorbance, as an expression of turbidity, was determined spectrophotometrically. Thermal protein denaturation of egg samples was analyzed by differential scanning calorimetry (DSC) using the dynamic method, and estimated for several thermal schedules by kinetics analysis. The DSC thermogram was characterized by two endothermic peaks in each sample. With increasing temperature, the yolk gradually turned from a plain orange to a vivid yellow color, while the white gradually changed from transparent to cloudy. For all samples, an accurate correlation was obtained between color changes and the non-denaturation ratio of the second peak temperature. Results are of potential value for the modeling and design of egg-based products. [ABSTRACT FROM AUTHOR]

A new sol–gel route using egg-white as the binder of metal ions, is developed to prepare hexagonal M-type SrFe 12 O 19 ferrite in this study, and the effects of different atomic ratio of Sr and Fe (Sr/Fe), sintering temperature ( T s ) and usage of egg-white ( M ew ) on the phase formation, morphology and magnetic properties of specimens are studied. It is found that the single-phase SrFe 12 O 19 ferrite only can be obtained under a Sr/Fe of 1:8 and a T s between 1000 °C and 1300 °C. The magnetic properties of specimens are also obviously affected by the different Sr/Fe and T s , primarily due to the emergency of impurities. The M ew has an obvious impact on the crystallinity of specimens, which consequently affects their magnetic properties. In our study, the optimum conditions to prepare the single-phase SrFe 12 O 19 ferrite are Sr/Fe=1:8, M ew = 3 g and T s =1200 °C. [ABSTRACT FROM AUTHOR]

Nano-crystalline ferrites with formula Ni 0.8 Zn 0.2 Cr x Fe 2− x O 4 ( x = 0.0–1.0) was synthesized using Egg-white auto-combustion method. An appropriate mechanism for complexation and ferrite formation was suggested. X-ray diffraction (XRD), Fourier transform infrared (FT-IR), Transmission electron microscopy (TEM), vibrating sample magnetometer (VSM) and a.c. electrical conductivity measurements were utilized to study the effect of Cr-substitution and its impact on particle size and electro-magnetic properties of the investigated ferrite. X-ray diffraction revealed single-phase cubic structure. The decrease in lattice parameter with increasing chromium was discussed in the view of ionic radii. TEM exhibited cubic agglomerated crystals with sizes between 10 and 20 nm. The decrease in the saturation magnetization and coercivity estimated through VSM measurements with increasing Cr-content indicated the preferential occupation of Cr 3+ ions in the octahedral sites. Ac-conductivity measurements revealed semiconducting behavior of the entire investigated samples at high temperature and revealed a magnetic transition from ferromagnetic to paramagnetic for the samples with Cr-content up to 0.2. The conductivity values as well as the conduction activation energies indicated that the Cr 3+ ions do not participate in the conduction and thus limit the Fe 2 + –Fe 3+ conduction by blocking up Fe 2 + –Fe 3+ transformation. [ABSTRACT FROM AUTHOR]

Abstract: Nano-crystalline nickel–zinc ferrites of different compositions; Ni1−x Zn x Fe2O4 (x=0.0–1.0) were prepared by a precursor method involving egg-white and metal nitrates. An appropriate mechanism for the egg-white-metal complexation was suggested. Differential thermal analysis-thermogravimetry, X-ray diffraction (XRD), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FT-IR), vibrating sample magnetometer and AC-magnetic susceptibility measurements were carried out to investigate chemical, structural and magnetic aspects of Ni–Zn ferrites. XRD confirmed the formation of spinel cubic structure. The average crystallite size was calculated using line broadening in XRD patterns. Structural parameters like lattice constant, X-ray density, bond lengths and inter-cationic distance were determined from XRD data. TEM showed agglomerated particles with average size agreed well with that estimated using XRD. FT-IR spectra confirm the formation of spinel structure and further lends support to the proposed cation distribution. Zn-content was found to have a significant influence on the magnetic properties of the system. The changes in the magnetic properties can be attributed to the influence of the cationic stoichiometry and their occupancy in the specific sites. [Copyright &y& Elsevier]

Abstract: Nano-sized NiFe2−x La x O4 ferrites (x=0.00, 0.01, 0.02, 0.03, 0.04, 0.5, 0.07 and 0.09) were synthesized for the first time by using metal nitrate and egg-white extract in aqueous medium. The ferrites were characterized by DTA-TG, XRD, TEM, FT-IR and VSM techniques. The thermal decomposition behavior revealed that the precursors were completely decomposed at about 420°C. TEM image shows agglomerated nanoparticles with crystallite sizes agrees well with that estimated by XRD measurement. XRD patterns show a secondary phase of LaFeO3 besides the cubic structure of the La-substituted ferrites. The lattice parameters, X-ray density and crystallite size were found to increase with the increasing La content. The VSM measurement exhibited a ferromagnetic property for all the samples at room temperature. With increasing La, M s was found to decrease while H c increased. The decrease in the saturation magnetization is attributed to the paramagnetic properties of lanthanum, which prefer to substitute iron present in the octahedral sites. The increase in the coercivity is due to either the stronger magnetocrystalline anisotropy induced by La substitution or the change in the crystallite size. [Copyright &y& Elsevier]

Abstract: Egg-white method was used to produce nanocrystalline Cr-substituted NiCuZn ferrites; Ni0.50Cu0.25Zn0.25Fe2−x Cr x O4 (0.0≤ x ≤1.0) from stoichiometric mixture of their respective metal nitrate. The structural, morphological and magnetic properties of the products were determined by X-ray powder diffractometry (XRD), Fourier transform infrared spectroscopy (FT-IR), transmission electron microscopy (TEM) and vibrating sample magnetometer (VSM). The average crystallite sizes obtained from XRD were between 15 and 25nm. Magnetization measurements indicated that when the Cr substitution increases the saturation magnetization decreases due to the magnetic character of the chromium ions which prefers octahedral site occupation. The coercivity was found to change proportionally with the particle sizes of the investigated ferrites. [ABSTRACT FROM AUTHOR]

Abstract: Nanocrystalline magnetic particles of Ni0.8− x Zn0.2Mg x Fe2O4 ferrites with x lying between 0.0 and 0.8 were synthesized using metal nitrates and freshly extracted egg-white. The synthesized powders were characterized using X-ray diffraction (XRD), Fourier transform infrared (FT-IR) and transmission electron microscopy (TEM). With increasing magnesium concentration, the lattice constant increases while X-ray density decreases. The average crystallite size determined from XRD data using Scherrer formula lie in the range of 35–59nm. TEM image shows spherically agglomerated particles with average crystallite size agreed well with that obtained from XRD. Magnetic properties measured at room temperature by vibrating sample magnetometer (VSM) reveal a decrease in saturation magnetization up to Mg content of 0.6. In agreement with FT-IR results, the unexpected increase in the magnetization at Mg content of 0.8 can be attributed to the tendency of Mg2+ ions to occupy the tetrahedral site. The decrease in the value of coercivity with increasing magnesium content can be explained based on the magneto-crystalline anisotropy. [Copyright &y& Elsevier]

Abstract: This paper examines the effect of copper substitution on the structural and magnetic properties in nano-crystalline ferrite series of nominal composition; Ni0.7−x Cu x Zn0.3Fe2O4 (where x =0.1–0.6) synthesized by a simple method using metal nitrates and freshly extracted egg-white. X-ray diffraction measurements (XRD) confirmed the formation of single-phase cubic spinel structure. The average crystallite size was calculated using XRD pattern and confirmed by transmission electron microscope (TEM). The nearly constant lattice parameters obtained with Cu substitution was attributed to the small difference in the ionic radius between Ni2+ and Cu2+ ions. FT-IR spectra showed two absorption bands assigned to the tetrahedral and octahedral complexes. The effect of Cu concentration on the magnetic properties was investigated using vibrating sample magnetometer (VSM) and molar magnetic susceptibility measurements. The decrease in the saturation magnetization and the Curie temperature values with increasing Cu content was explained in terms of the magnetic moments and magnetic exchange interaction existing between the antiparallel uncompensated electron spin of A and B sublattices. The magnetic measurements also proved that the entire preparation method has a great effect on enhancing the magnetic properties of the system. [Copyright &y& Elsevier]

• Strong and weak cation exchange cryogels were prepared for the purify lysozyme from whole egg white. • The maximum lysozyme adsorption capacity onto poly(HEMA-GMA)-SO 3 H cryogel was 188.3 mg/g. • The extraction of lysozyme from egg-white was reached to 93.4% with strong cation cryogel. Here, the macroporous poly(hydroxylmethyl methacrylate/glycidyl methacrylate [p(HEMA-GMA)] cryogels with large porous surface were prepared, and then the epoxy groups of the p(HEMA-GMA) cryogels were systematically modified into strong and weak cationic groups. The effects of initial protein concentrations, adsorption time, pH, salt concentrations and temperatures on adsorption efficiency of cation exchange cryogels for lysozyme were determined. The maximum lysozyme adsorption capacities of strong and weak cation exchange cryogels were found to be 188.3 and 79.7 mg/g cryogel at 25 °C, respectively. The performance of the strong cationic cryogel was evaluated by purification of lysozyme from egg white. The activity of the isolated lysozyme was found to be 21,347 U/mg. The cationic cryogel maintained its expected high adsorption capacity and efficiency of the purification levels during repeated adsorption desorption processes. Finally, the purpose of this work is the design a cation exchange system for purification of lysozyme from egg-white. [ABSTRACT FROM AUTHOR]