Purification of lysozyme from chicken egg white by high-density cation exchange adsorbents in stirred fluidized bed adsorption system

Ovotransferrin, an alternative and potential protein for diverse food and nutritional applications

Ovotransferrin(OVT)is a protein found in many types of egg white and has a wide range of functional properties. It has 50% homology with human/bovine lactoferrin, and is expected to be one of the most important alternative proteins for use in food and nutritional applications. This paper mainly reviews the structural characteristics and chemical properties of OVT, as well as its extraction and purification methods. It also systematically describes the various biological activities of OVT and its applications in food and medical industries. The challenges and limitations in the research of OVT were suggested. This review recommends some possible methods such as nanoparticle carriers and microencapsulation to improve the bioavailability and stability of OVT. In addition, this review highlights several strategies to overcome the limitations of OVT in terms of preparation and purification. This review systematically summarizes the recent advances in OVT and will provide guidance for the its development for food and nutritional applications.

Noncytotoxic WORM Memory Using Lysozyme with Ultrahigh Stability for Transient and Sustainable Electronics Applications

Biocompatibility and transient nature of electronic devices have been the matter of attention in recent times due to their immense potential for sustainable solutions toward hazardous e-wastes. In order to fulfill the requirement of high-density data-storage devices due to explosive growth in digital data, a resistive switching (RS)-based memory device could be the promising alternative to the present Si-based electronics. In this research work, we employed a biocompatible enzymatic protein lysozyme (Lyso) as the active layer to design a RS memory device having a device structure Au/Lyso/ITO. Interestingly the device showed transient, WORM memory behavior. It has been observed that the WORM memory performance of the device was very good with high memory window (2.78 × 102), data retention (up to 300 min), device yield (∼73.8%), read cyclability, as well as very high device stability (experimentally >700 days, extrapolated to 3000 days). Bias-induced charge trapping followed by conducting filament formation was the key behind such switching behavior. Transient behavior analysis showed that electronic as well as optical behaviors completely disappeared after 10 s dissolution of the device in luke warm water. Cytotoxicity of the as-prepared device was tested by challenging two environmentally derived bacteria, S. aureus and P. aeruginosa, and was found to have no biocidal effects. Hence, the device would cause no harm to the microbial flora when it is discarded. As a whole, this work suggests that Lyso-based WORM memory device could play a key role for the design of transient WORM memory device for sustainable electronic applications.

Reactive Green 19 dye-ligand immobilized on the aminated nanofiber membranes for efficient adsorption of lysozyme: Process development and optimization in batch and flow systems

The performance of lysozyme adsorption by the aminated nanofiber membrane immobilized with Reactive Green 19 (RG19) dyes was evaluated in batch and flow systems. The physicochemical properties of the dye-immobilized nanofiber membrane were characterized. The parameters of batch-mode adsorption of lysozyme (e.g., pH, initial dye concentration, and lysozyme concentration) were optimized using the Taguchi method. In a flow process, the factors influencing the dynamic binding performance for lysozyme adsorption in the chicken egg white (CEW) solution include immobilized dye concentration, adsorption pH value, feed flow rate, and feed CEW concentration. The impact of these operating conditions on the lysozyme purification process was investigated. Under optimal conditions, the recovery yield and purification factor of lysozyme achieved from the one-step adsorption process were 98.52% and 143 folds, respectively. The dye-affinity nanofiber membrane also did not exhibit any significant loss in its binding capacity and purification performance after five consecutive uses.

The Impact of Processing and Extraction Methods on the Allergenicity of Targeted Protein Quantification as Well as Bioactive Peptides Derived from Egg

This review article discusses advanced extraction methods to enhance the functionality of egg-derived peptides while reducing their allergenicity. While eggs are considered a nutrient-dense food, some proteins can cause allergic reactions in susceptible individuals. Therefore, various methods have been developed to reduce the allergenicity of egg-derived proteins, such as enzymatic hydrolysis, heat treatment, and glycosylation. In addition to reducing allergenicity, advanced extraction methods can enhance the functionality of egg-derived peptides. Techniques such as membrane separation, chromatography, and electrodialysis can isolate and purify specific egg-derived peptides with desired functional properties, improving their bioactivity. Further, enzymatic hydrolysis can also break down polypeptide sequences and produce bioactive peptides with various health benefits. While liquid chromatography is the most commonly used method to obtain individual proteins for developing novel food products, several challenges are associated with optimizing extraction conditions to maximize functionality and allergenicity reduction. The article also highlights the challenges and future perspectives, including optimizing extraction conditions to maximize functionality and allergenicity reduction. The review concludes by highlighting the potential for future research in this area to improve the safety and efficacy of egg-derived peptides more broadly.

Extraction and Characterization of Lysozyme from Salted Duck Egg White

Salted duck egg white (SDEW), as the main by-product in the production process of salted egg yolk, has not been effectively used as a food resource because of its high salt concentration. This study creatively used isoelectric point precipitation, ultrafiltration, and cation exchange to separate and purify lysozyme from SDEW and preliminarily explored the enzymatic properties of lysozyme. The results showed that the relative molecular weight of lysozyme was about 14 KDa, and the specific activity of lysozyme reached 18,300 U/mg. Lysozyme had good stability in the temperature range of 30 °C to 60 °C and pH of 4 to 7. Metal ions, Fe²⁺, Cu²⁺, and Zn²⁺, strongly inhibited lysozyme activity. Different surfactants showed certain inhibition effects on lysozyme from SDEW, among which glycerin had the strongest inhibitory effect. This study aimed to provide a theoretical reference for industrial purification and production of lysozyme from SDEW.

Functional Properties and Extraction Techniques of Chicken Egg White Proteins

Chicken egg whites contain hundreds of proteins, and are widely used in the food, biological and pharmaceutical industries. It is highly significant to study the separation and purification of egg white proteins. This review first describes the structures and functional properties of several major active proteins in egg whites, including ovalbumin, ovotransferrin, ovomucoid, lysozyme, ovomucin, ovomacroglobulin and avidin. Then, the common techniques (including precipitation, chromatography and membrane separation) and some novel approaches (including electrophoresis, membrane chromatography, aqueous two-phase system and molecular imprinting technology) for the separation and purification of egg white proteins broadly reported in the current research are introduced. In addition, several co-purification methods for simultaneous separation of multiple proteins from egg whites have been developed to improve raw material utilization and reduce costs. In this paper, the reported techniques in the last decade for the separation and purification of chicken egg white proteins are reviewed, discussed and prospected, aiming to provide a reference for further research on egg proteins in the future.

Selective isolation and sensitive detection of lysozyme using aptamer based magnetic adsorbent and a new quartz crystal microbalance system

Magnetic chitosan beads and quartz crystal microbalance chip were decorated with lysozyme specific aptamer for isolation and detection of lysozyme, respectively. The lysozyme specific aptamer was immobilized on poly (dopamine) coated magnetic chitosan beads and the chip via Schiff base reaction. The percentage of the removal efficiency and purity of the isolated lysozyme from egg white were 87.6% and 91.8%, respectively. Further, the sensor system was contacted with different concentrations of lysozyme and other test proteins. This sensor system provided a method for the label-free, concentration-dependent, and selective detection of lysozyme with an observed detection limit of 17.9 ± 0.6 ng/mL. The sensor system was very selective and not significantly responded to the other tested proteins such as ovalbumin, trypsin, cytochrome C, and glucose oxidase. The prepared new sensor system showed a good durability and a high sensitivity for determination of lysozyme from solutions and whole egg white.

Adsorption behavior of fluoroquinolone(ciprofloxacin) using zinc oxide impregnated activated carbon prepared from jack fruit peel: Kinetics and isotherm studies

Ciprofloxacin is a pharmaceutical component used for treating various tract infections. This is considered as an emerging contaminant due to the release of unreacted components getting disposed into the water bodies. This component is effectively treated using renewable biomass, which is converted into a useful renewable low-cost adsorbent material. Discarded Jack Fruit Peel (JFP) is used as an activated carbon incorporated with zinc oxide nanocomposite. The prepared activated carbon in this experiment was characterized by determining their functional groups, morphological characters, and nature of the adsorbent material by analyzing the Fourier Transform InfraRed (FTIR), Field Emission Scanning Electron Microscopy (FESEM), and X-ray Diffraction (XRD) characterization. Further, the prepared composite's correlation coefficients and equilibrium sorption of the adsorption process were calculated using Ultra Violet (UV)-Visible Spectroscopy and analyzed with isotherm models (Langmuir model, Freundlich model, and Temkin model) and kinetic models (Pseudo-first-order kinetics, Pseudo-second-order kinetics, Intraparticle diffusion model, and Elovich model). Among the different models, the Zinc oxide impregnated activated carbon show Freundlich Isotherm and Pseudo Second order equation having a maximum correlation with experimental studies indicating double-layer adsorption, which suggests that the process is chemisorption. The operational parameters, including the effect of pH, dosage of activated carbon, and contact time of adsorption was calculated to identify the optimal condition for maximum adsorption.