Dietary High‐Oleic Acid Soybean Oil Dose Dependently Attenuates Egg Yolk Content of n‐3 Polyunsaturated Fatty Acids in Laying Hens Fed Supplemental Flaxseed Oil

Chickens can hepatically synthesize eicosapentaenoic acid (20:5 n‐3) and docosahexaenoic acid (22:6 n‐3) from α‐linolenic acid (ALA; 18:3 n‐3); however, the process is inefficient and competitively inhibited by dietary linoleic acid (LNA; 18:2 n‐6). In the present study, the influence of dietary high‐oleic acid (OLA; 18:1 n‐9) soybean oil (HOSO) on egg and tissue deposition of ALA and n‐3 polyunsaturated fatty acids (PUFA) synthesized from dietary ALA was investigated in laying hens fed a reduced‐LNA base diet supplemented with high‐ALA flaxseed oil (FLAX). We hypothesized that reducing the dietary level of LNA would promote greater hepatic conversion of ALA to very long‐chain (VLC; >20C) n‐3 PUFA, while supplemental dietary HOSO would simultaneously further enrich eggs with OLA without influencing egg n‐3 PUFA contents. Nine 51‐week‐old hens each were fed 0, 10, 20, or 40 g HOSO/kg diet for 12 weeks. Within each group, supplemental dietary FLAX was increased every 3 weeks from 0 to 10 to 20 to 40 g/kg diet. Compared to controls, dietary FLAX maximally enriched the total n‐3 and VLC n‐3 PUFA contents in egg yolk by 9.4‐fold and 2.2‐fold, respectively, while feeding hens 40 g HOSO/kg diet maximally attenuated the yolk deposition of ALA, VLC n‐3 PUFA, and total n‐3 PUFA by 37, 15, and 32%, respectively. These results suggest that dietary OLA is not neutral with regard to the overall process by which dietary ALA is absorbed, metabolized, and deposited into egg yolk, either intact or in the form of longer‐chain/more unsaturated n‐3 PUFA derivatives.     

Microfiltration and stabilization of egg yolk phospholipid emulsions by a microporous glass membrane

A microporous glass membrane with a narrow-range pore size was applied for the microfiltration of egg yolk phospholipid emulsions. The oil-in-water and water-in-oil emulsions were successfully filtered using the membrane without any coalescence of oil droplets or the breakdown of the emulsions. The filtrated oil-in-water emulsion was stable for at least 6 wk when stored at 5°C. The results obtained suggest that the technique would be valuable for the precise filtration of emulsions for food uses as well as intravenous fat and/or drug carrier emulsions, and offer the stabilization of the emulsions.     

ICP-MS法测定地衣和鸡蛋粉中9种微量元素及其不确定度的评定

用硝酸和高氯酸混合酸消解样品 ,ICP MS法同时测定地衣和鸡蛋粉中Mn、Cu、Zn、Sr、Cd、Fe、Pb、As和Se9种微量元素的含量。在优化实验下 ,测得检出限为 (ng/L) :55Mn2 ,6 3Cu4 ,56 Fe4 ,6 6 Zn9,88Sr1,114 Cd2 ,2 0 8Pb5 ,75As12 ,80 Se6 0。用国家一级标准物质甘兰GBW0 85 0 4验证方法的准确度 ,测定值与标准值吻合较好。并对不确定度的评定程序举例说明     

Effect of oxidation induced by hydroxyl radical‐mediated model on molecular structural and physical character of egg white powder

The objective of this study was to determine structure and functional properties changes of oxidised egg white protein derived from hydrogen peroxide (H₂O₂)/ferric chloride (FeCl₃) /ascorbic acid hydroxyl radical‐generating systems at room temperature, including carbonyls, sulfhydryl and total sulfhydryl groups, dityrosine, free amino, surface hydrophobicity, particle size distribution, intermolecular forces, and foamability and emulsibility. Protein carbonyl and dityrosine content of egg white protein were increased (P < 0.05) with increasing the concentrations of H₂O₂. Oxidation decreased free sulfhydryl, total sulfhydryl groups and surface of hydrophobicity comparing with nonoxidised egg white protein. Oxidation also reduced its free amino content (P < 0.05). The low concentration of H₂O₂ contributing the average particle size of egg white protein was smaller than the control group. However, the high concentrations of H₂O₂ caused that egg white protein aggregated and the average particle size became larger. To sum up, oxidation made EWP denaturation and aggregation.     

Macromolecular crowding affects protein photosensitivity: The case of egg white immunoreactivity

An aqueous solution containing 0.1 g/l egg white proteins was exposed to increasing irradiance (0, 1.6, 7.2, 10.5, 17.0 and 29.1 W m⁻²) UV-C light for up to 30 min at 8 °C. In all cases, a decrease in immunoreactivity was detected. A 10-fold decrease of immunoreactivity was obtained in circa 7 min at 29.1 W/m² and in more than 4 h at 1.6 W/m². The loss of immunoreactivity was attributed to denaturation phenomena leading to the formation of protein fragments partially retaining the original epitopes. A progressive decrease in protein photosensitivity was observed by increasing its concentration. Above a limit concentration of 2.2 g/l, egg white proteins became extremely resistant to UV-light, even prolonging exposure time at 29.1 W/m² to 3 h. Photostability of egg white proteins was attributed to the occurrence of crowding effects which favoured protein folding and hindered photolysis.     

Comparing effects of α‐ vs. β‐chitosan coating and emulsion coatings on egg quality during room temperature storage

Effects of α‐ and β‐chitosan (CH), soybean oil (SO) and their emulsions (CH:SO = 2:3) as coating materials on selected internal quality and sensory properties of eggs were evaluated during 5 weeks storage at 25 °C. After 3 weeks of storage, α‐ and β‐CH‐coated eggs changed to B grade, while SO‐ and emulsion‐coated eggs preserved grade A quality. Weight loss of eggs coated with SO and CH:SO emulsions was <2.0% vs. 5.3–5.8% for noncoated and CH‐coated eggs after 5 weeks of storage. β‐CH (0.9%) maintained lower weight loss of eggs than α‐CH (1.2%) only at 1‐week storage. Albumen pH of eggs coated with SO and CH:SO emulsions decreased progressively throughout storage. Eggs coated with β‐CH:SO emulsion and SO were significantly glossier than noncoated eggs. Consumers indicated positive purchase intent (69.17–76.67%) for all coated eggs. Overall, α‐CH:SO and β‐CH:SO emulsions extended egg shelf life by at least 3 weeks during room temperature storage.     

Mineralization of Calcium Carbonate Induced by Egg Substrate and an Electric Field

Egg substrates, including eggshell, egg membranes, and egg white, exert a significant influence on CaCO₃ biomineralization. CaCO₃ crystallization at different temperatures, concentrations, and with various egg substrates was systematically investigated via rapidly mixing solution method. The crystals were determined by scanning electron microscopy, Fourier transform infrared spectroscopy, and X‐ray diffraction. As the CaCl₂ concentration increased, the CaCO₃ crystal form gradually changed from calcite to vaterite. Under rising temperature, the single‐hole vaterite and besom‐like aragonite were formed on the raw and boiled egg white substrate, respectively. The effects of electric field on CaCO₃ crystallization were also explored. The findings may offer a novel approach to CaCO₃ synthesis.     

Foam-Mat Freeze Drying of Egg White—Mathematical Modeling Part II: Freeze Drying and Modeling

Foam-mat freeze drying is one of the promising methods of drying, which utilizes advantages of both freeze drying and foam-mat drying. Egg white with its excellent foaming properties makes a suitable candidate for foam-mat freeze drying. Experiments were conducted to study foam-mat freeze drying of egg white, in an effort to determine the suitability of this method. Xanthan gum (XG) at 0.125% concentration was used as stabilizer for foaming. The results showed that the addition of xanthan gum during foaming has a positive impact in reducing the total drying time and also produces excellent quality egg white powder. The addition of stabilizer also plays an important role in improving drying. Simple models were applied for determining drying time and diffusion coefficients during freeze drying.     

Effect of salt content on the rheological properties of salad dressing-type emulsions stabilized by emulsifier blends

The effects that salt content and composition of emulsifier blends exert on the rheological properties of salad dressing-type emulsions were studied. Binary blends of egg yolk and different types of amphiphilic molecules (Tween 20, sucrose laurate and pea protein), in several proportions, were used to stabilize emulsions. Salt concentration was ranged from 0 to 2.3% w/w. Steady-state flow tests and small-amplitude oscillatory shear measurements within the linear viscoelastic region were carried out. Rheological tests were complemented with droplet size distribution measurements. Rheological properties and physical stability of the emulsions studied were significantly influenced by salt content and the nature of binary emulsifier blends. In general, the values of rheological parameters studied increased with salt content. However, salt affects in much higher extent the properties of emulsions stabilized by high proportions of egg yolk or pea protein in the emulsifier blend, rather than those mainly stabilized by non-ionic low-molecular-weight surfactants, which are less sensitive to changes in the ionic strength. In this sense, the increase observed in the values of viscosity and linear viscoelastic functions of emulsions is more important when a protein is predominant in the emulsifier blend. This effect was explained on the basis of a more apparent increasing interdroplet interactions and viscosity of the continuous medium, both of them induced by salt addition, which lead to the consecution of an extensively flocculated state and improved creaming stability. On the contrary, different blends of pea protein and egg yolk showed a quite similar evolution of the rheological parameters with salt concentration.     

Extraordinary adsorption of acidic fuchsine and malachite green onto cheap nano-adsorbent derived from eggshell

Removal of dyestuffs such as Acidic Fuchsine(AF) and Malachite Green(MG) being present in many forms in industries is vital to protect water reservoirs from their catastrophic effects on the ecosystem. This study attempts to effectively eliminate these dyes using a low-cost and eco-friendly material. Eggshell, as a biocompatible by-product,was initially characterized, then some modifications were conducted, and its morphology and chemical structure were then examined through(Atomic force microscopy) AFM,(Fourier-Transform Infrared Spectroscopy) FTIR,(Energy-Dispersive X-ray Spectroscopy) EDS and(Brunauer–Emmett–Teller) BET analyses. They revealed that the modifications on raw material gave rise to a natural nano-adsorbent presenting porous medium appropriate for targeted adsorbate molecules with the average particle size and average pore diameter of 54 and ～2 nm, respectively. Functional groups on the adsorbent surface were also of importance to assist the adsorption of AF and MG.The effect of contact time, adsorbent dose, solution p H and initial concentration was evaluated. Pseudo-second order model accurately correlated the experimental kinetic data for both dyes. Moreover, the participation of intra-particle diffusion along with film diffusion in controlling the process was suggested. Langmuir isotherm model fitted very well to the equilibrium data for both dyes and maximum monolayer adsorption capacity of AF and MG was accordingly calculated to be 5000 and 3333.33 mg·g~(-1) respectively. The inherent characteristics of eggshell make it a potential material to remove contaminants from wastewater in future applications.