Chemical composition of chicken eggshell and shell membranes

White Isthmus Transcriptome Analysis Reveals the Mechanism of Translucent Eggshell Formation

The presence of translucent eggshells is a type of egg quality issue that impacts egg sales. While many researchers have studied them, the exact mechanisms behind their formation remain unclear. In this study, we conducted a transcriptomic differential expression analysis of the isthmus region of the oviduct in both normal egg- and translucent egg-laying hens. The analysis revealed that differentially expressed gene pathways were predominantly concentrated in the synthesis, modification, and transport of eggshell membrane proteins, particularly collagen proteins, which provide structural support. These findings suggest that variations in the physical structure of the eggshell membrane, resulting from changes in its chemical composition, are the fundamental cause of translucent eggshell formation. This research provides a theoretical reference for reducing the occurrence of translucent eggs.

A Novel Candidate for Guided Tissue Regeneration: Chitosan and Eggshell Membrane

Background The primary cause of adult tooth loss is commonly attributed to periodontal disease, a condition that weakens the supportive structures around the teeth. In addressing periodontal diseases, surgeons often employ the guided tissue regeneration (GTR) technique, which involves the use of a barrier membrane. Aim The aim of the present study is to assess the composition and mechanical strength of chitosan and eggshell membrane. This research was conducted to provide insights into their potential application in facilitating tissue regeneration. Materials and procedures Chitosan and eggshell membrane were combined to create the membrane. Scanning electron microscopy (SEM) using FEI Quanta FEG 650 SEM (JSM IT-800, JEOL Ltd., Akishima, Tokyo, Japan) was carried out, and mechanical properties were used to measure the parameters of membrane characterization.  Results In the dry condition, the membrane's tensile strength was 0.30 MPa and its elongation at break was 8.2%. In the wet condition, the membrane's tensile strength was 0.13 MPa and its elongation at break was 22.6%. The SEM results depicted membrane surface with pore sizes ranging from 16 to 100 meters, and the result obtained from membrane porosity test was 31.2%.  Conclusion The chitosan-eggshell membrane exhibited a fibrous surface with a desirable pore size for use as a GTR membrane, but it has low mechanical strength.

Cytotoxic-Ag-Modified Eggshell Membrane Nanocomposites as Bactericides in Concrete Mortar

Against the backdrop of escalating infrastructure budgets worldwide, a notable portion-up to 45%-is allocated to maintenance endeavors rather than innovative infrastructure development. A substantial fraction of this maintenance commitment involves combatting concrete degradation due to microbial attacks. In response, this study endeavors to propose a remedial strategy employing nano metals and repurposed materials within cement mortar. The methodology entails the adsorption onto eggshell membranes (ESM) of silver nitrate (ESM/AgNO3) or silver nanoparticles (ESM/AgNPs) yielding silver-eggshell membrane composites. Subsequently, the resulting silver-eggshell membrane composites were introduced in different proportions to replace cement, resulting in the formulation of ten distinct mortar compositions. A thorough analysis encompassing a range of techniques, such as spectrophotometry, scanning electron microscopy, thermogravimetric analysis, X-ray fluorescence analysis, X-ray diffraction (XRD), and MTT assay, was performed on these composite blends. Additionally, evaluations of both compressive and tensile strengths were carried out. The mortar blends 3, 5, and 6, characterized by 2% ESM/AgNO3, 1% ESM/AgNPs, and 2% ESM/AgNPs cement replacement, respectively, exhibited remarkable antimicrobial efficacy, manifesting in substantial reduction in microbial cell viability (up to 50%) of typical waste activated sludge. Concurrently, a marginal reduction of approximately 10% in compressive strength was noted, juxtaposed with an insignificant change in tensile strength. This investigation sheds light on a promising avenue for addressing concrete deterioration while navigating the balance between material performance and structural integrity.

A drug-incorporated-microparticle-eggshell-membrane-scaffold (DIMES) dressing: A novel biomaterial for localised wound regeneration

Chronic wounds affect millions of people annually and have emotional and financial implications in addition to health issues. The current treatment for chronic wounds involves the repeated use of bandages and drugs such as antibiotics over an extended period. A cost-effective and convenient solution for wound healing is the development of drug-incorporated bandages. This study aimed to develop a biocompatible bandage made of drug-incorporated poly (lactic-co-glycolic acid) (PLGA) microparticles (MPs) and eggshell membrane (ESM) for cornea wound healing. ESM has desirable properties for wound healing and can be isolated from eggshells using acetic acid or ethylenediaminetetraacetic acid (EDTA) protocols. Fluorescein isothiocyanate-labelled Bovine Serum Albumin (FITC-BSA) was used as a model drug, and the PLGA MPs were fabricated using a solvent extraction method. The MPs were successfully attached to the fibrous layer of the ESM using NaOH. The surface features of the ESM samples containing MPs were studied using a field emission scanning electron microscope (FESEM) and compared with blank ESM images. The findings indicated that the MPs were attached to the ESM fibres and had similar shapes and sizes as the control MPs. The fibre diameters of the MPs samples were assessed using Fiji-ImageJ software, and no significant changes were observed compared to the blank ESM. The surface roughness, Ra values, of the MPs incorporated ESM samples were evaluated and compared to the blank ESM, and no significant changes were found. Fourier transform infrared (FTIR) spectroscopy was used to analyse the chemical Composition of the bandage, and the spectra showed that the FBM were effectively incorporated into the ESM. The FTIR spectra identified the major peaks of the natural ESM and the PLGA polymer in the bandage. The bandage was transparent but had a reduced visibility in the waterproof test card method. The bandage achieved sustained drug release up to 10 days and was found to be biocompatible and non-toxic in a chorioallantoic membrane (CAM) assay. Overall, the drug-incorporated PLGA MPs-ESM bandage has great potential for treating chronic wounds.

Fingermarks in wildlife forensics: A review

Wildlife forensics is defined as providing forensic evidence to support legal investigations involving wildlife crime, such as the trafficking and poaching of animals and/ or their goods. While wildlife forensics is an underexplored field of science, the ramifications of poaching can be catastrophic. The consequences of wildlife crime include disease spread, species and habitat loss, human injury, and cultural loss. Efforts to use forensic science to combat poaching are currently limited to DNA-based techniques. However, fingermark analysis for the identification of perpetrators of wildlife crimes has not been explored to the same extent, despite being a cost-effective, simple-to-use forensic method that is easy to deploy in-field. This review covers literature that has explored fingermark examination techniques used on wildlife-related samples, such as pangolin scales, ivory-based substances, bone, and eggs, as well as feathers and skins, among more obscure trafficked items. Useful preliminary work has been conducted in this subject area, demonstrating that commonly used fingermark analysis techniques can be applied to wildlife-based items. However, many of these studies suffer from limitations in terms of experimental design. More work should be done on creating studies with larger sample sizes and novel approaches should be validated under environmental conditions that mimic real crime scenes. Further research into determining the forensic fingermark analysis techniques that perform the most efficiently in the environmental conditions of the countries where they are needed would therefore benefit legal investigations and help to reduce instances of poaching.

Synthesis and Assessment of Antimicrobial Composites of Ag Nanoparticles or AgNO3 and Egg Shell Membranes

Engineering research has been expanded by the advent of material fusion, which has led to the development of composites that are more reliable and cost-effective. This investigation aims to utilise this concept to promote a circular economy by maximizing the adsorption of silver nanoparticles and silver nitrate onto recycled chicken eggshell membranes, resulting in optimized antimicrobial silver/eggshell membrane composites. The pH, time, concentration, and adsorption temperatures were optimized. It was confirmed that these composites were excellent candidates for use in antimicrobial applications. The silver nanoparticles were produced through chemical synthesis using sodium borohydride as a reducing agent and through adsorption/surface reduction of silver nitrate on eggshell membranes. The composites were thoroughly characterized by various techniques, including spectrophotometry, atomic absorption spectrometry, scanning electron microscopy, transmission electron microscopy, Fourier transform infrared spectroscopy, and X-ray photoelectron spectroscopy, as well as agar well diffusion and MTT assay. The results indicate that silver/eggshell membrane composites with excellent antimicrobial properties were produced using both silver nanoparticles and silver nitrate at a pH of 6, 25 °C, and after 48 h of agitation. These materials exhibited remarkable antimicrobial activity against Pseudomonas aeruginosa and Bacillus subtilis, resulting in 27.77% and 15.34% cell death, respectively.

Fear, anxiety, and production in laying hens with healed keel bone fractures

For laying hens, the immediate aftermath and healing period of a keel fracture (KF) is characterized by reduced ability to perform species-specific behavior, access resources, and pain. However, the longer-term impacts, once the fracture is completely healed, are less clear. As well as acute pain and behavioral changes, a negative experience can shape future responses to putatively threatening stimuli, raising future fear, and anxiety levels during husbandry-related events. We aimed to determine whether hens that had previously sustained keel bone fractures, but were now outside of the peak age range for new fractures, showed higher fear and anxiety levels compared to intact hens. We also determined if healed keel bone fractures were associated with reduced production, changes in behavior and resource use. One hundred and fifty hens with a palpation score of 1 ( "KF") and 150 hens with a palpation score of 0 (keel fracture free, "KFF") were selected from a commercial farm at 63 wk of age and housed in 6 groups (3 × KF and 3 × KFF). We compared production (hen weight and feed consumption, egg quantity, quality and weight, floor eggs, shell thickness, and weight) and home pen behavior (behaviors and transitional movements) in both groups. Finally, we measured the responses of KF (n = 75) and KFF (n = 75) during tonic immobility, novel arena, and novel object tests. KF and KFF hens did not differ in their responses to the tonic immobility, novel arena, and novel object tests, nor were there differences between the 2 groups in home pen behavior and transitional movements. KFF birds were lighter and laid eggs with less eggshell membrane compared KF birds, but no differences were found between KF and KFF in any other production measures. We found no evidence that healed KFs were associated with detrimental welfare effects in laying hens, but further work is required to determine the mechanisms and implications of the lower body weight and egg shell membrane.

Selective enrichment of glycopeptides using ground eggshell materials

The current research of protein glycosylation is focused on develop various functionalized hydrophilic materials that can effectively enrich glycopeptides. However, most of these materials require complex synthesis steps, plenty of chemical reagents, and high cost. In this study, we employed the natural eggshell for glycopeptides enrichment for the first time. Using horseradish peroxidase (HRP) tryptic digest as a standard sample, eggshell exhibited excellent sensitivity (0.05 fmol μL^-1), good selectivity [HRP tryptic digest:bovine serum albumin (BSA) tryptic digest = 1:1000], excellent size-exclusion effect (HRP tryptic digest:BSA protein = 1:10,000), good loading capacity (75 mg g^-1), and recovery (97.6 ± 0.3%). In addition, 153 and 114 glycopeptides were captured by eggshell from the serum tryptic digests of normal humans and diabetic patients, respectively. Benefiting from the singular porous structure and abundant biomass, eggshell performed excellently in the capture and separation of glycopeptides. These results demonstrated the potential of environmentally friendly eggshell in glycosylation proteomics analysis.

Visual Detection and Sensing of Mercury Ions and Glutathione Using Fluorescent Copper Nanoclusters

Visual detection of mercury ions and glutathione is of great significance to public health and environmental issues. Herein, we developed a fluorescent sensor (l-Cys/CuNCs@ESM) based on the eggshell membrane (ESM) and red-emitting copper nanoclusters (CuNCs) by the in situ strategy via l-cysteine (l-Cys) as the reducing and protective agent for mercury ions and glutathione sensing visually. The as-prepared fluorescent product had good stability, portability, large Stokes shift (250 nm), and long fluorescence lifetime (7.3 μs). Notably, the l-Cys/CuNCs@ESM exhibited a specific fluorescence quenching response toward Hg²⁺. Moreover, the interaction between glutathione (GSH) and Hg²⁺ could subsequently recover the fluorescence effectively. Inspired by this "on-off-on" switch, the l-Cys/CuNCs@ESM was applied as the dual-sensing system for visual detection of mercury ions and glutathione integrating with the portable smartphone. The limit of detection (LOD) of Hg²⁺ is 1.1 μM for visualization and 0.52 μM for the fluorescence spectrometer. The corresponding LODs of GSH are 2.8 and 0.59 μM, respectively. This platform presents significant sensitivity, specificity, and stability, offering a promising potential for real-time/on-site sensing.

Advances in eggshell membrane separation and solubilization technologies

Eggshell membranes (ESM) contain 90% protein, 3% lipids, 2% sugars, and small amounts of minerals such as calcium and magnesium. Of the 90% of proteins present, 472 proteins species have been identified. ESM provide the initial mineralization platform for eggshell formation, and can be used for to produce adsorbents, cosmetics, and medical products because of their special physical structure and chemical composition. The special physical structure of the eggshell membrane, with disulfide bonds between and within the protein molecules and the cross-linking of lysine-derived and heterochain chains between the eggshell membrane, makes the membrane very difficult to dissolve, with a maximum solubility rate of only 62%. Also, the insolubility of ESM limits its development and use also any related research. Based on the physical structure and chemical composition of the eggshell membrane, this paper reviews the latest research on eggshell membrane separation and membrane protein solubilization to provide a reference for promoting the separation, dissolution, and rational development and use of the avian eggshell membrane.

Eggshell Membrane as a Biomaterial for Bone Regeneration

The physicochemical features of the avian eggshell membrane play an essential role in the process of calcium carbonate deposition during shell mineralization, giving rise to a porous mineralized tissue with remarkable mechanical properties and biological functions. The membrane could be useful by itself or as a bi-dimensional scaffold to build future bone-regenerative materials. This review focuses on the biological, physical, and mechanical properties of the eggshell membrane that could be useful for that purpose. Due to its low cost and wide availability as a waste byproduct of the egg processing industry, repurposing the eggshell membrane for bone bio-material manufacturing fulfills the principles of a circular economy. In addition, eggshell membrane particles have has the potential to be used as bio-ink for 3D printing of tailored implantable scaffolds. Herein, a literature review was conducted to ascertain the degree to which the properties of the eggshell membrane satisfy the requirements for the development of bone scaffolds. In principle, it is biocompatible and non-cytotoxic, and induces proliferation and differentiation of different cell types. Moreover, when implanted in animal models, it elicits a mild inflammatory response and displays characteristics of stability and biodegradability. Furthermore, the eggshell membrane possesses a mechanical viscoelastic behavior comparable to other collagen-based systems. Overall, the biological, physical, and mechanical features of the eggshell membrane, which can be further tuned and improved, make this natural polymer suitable as a basic component for developing new bone graft materials.

Using in vitro bioassays to guide the development of safer bio-based polymers for use in food packaging

Petroleum-based polymers traditionally used for plastic packaging production have been shown to leach dangerous chemicals such as bisphenol-A (BPA). Bio-based polymers are potentially safer alternatives, and many can be sustainably sourced from waste streams in the food industry. This study assesses bio-based polymers undergoing food packaging development for migration of endocrine disrupting leachates at the level of estrogen, androgen and progestagen nuclear receptor transcriptional activity. Reporter gene assays were coupled with migration testing, performed using standardised test conditions for storage and temperature. Test samples include nine bio-based polymers and four inorganic waste additives mixed with a traditional petroleum-based polymer, polypropylene. Thermoplastic starch material, polybutylene succinate, polycaprolactone, polybutylene adipate terephthalate (PBAT), two polylactic acid (PLA)/PBAT blends, polyhydroxybutyrate (PHB) and eggshell/polypropylene (10:90) presented no significant reduction in metabolic activity or hormonal activity under any test condition. Polypropylene (PP) presented no hormonal activity. Metabolic activity was reduced in the estrogen responsive cell line after 10 days migration testing of eggshell/polypropylene (0.1:99.9) in MeOH at 40°C, and PP in MeOH and dH₂0. Estrogenic agonist activity was observed after 10 days in poultry litter ash/polypropylene (10:90) in MeOH at 20°C and 40°C, poultry feather based polymer in MeOH and dH₂O at 40°C, and eggshell/polypropylene (40:60) and PLA in dH₂O at 40°C. Activity was within a range of 0.26–0.50 ng 17β-estradiol equivalents per ml, equating to an estrogenic potency of 3–∼2800 times less than the estrogenic leachate BPA. Poultry litter ash/polypropylene (10:90) in MeOH for 10 days presented estrogenic activity at 20°C and 40°C within the above range and anti-androgenic activity at 40°C. Progestagenic activity was not observed for any of the compounds under any test condition. Interestingly, lower concentrations of eggshell or PP may eliminate eggshell estrogenicity and PP toxicity. Alternatively eggshell may bind and eliminate the toxic elements of PP. Similarly, PLA estrogenic activity was removed in both PLA/PBAT blends. This study demonstrates the benefits of bioassay guidance in the development of safer and sustainable packaging alternatives to petroleum-based plastics. Manipulating the types of additives and their formulations alongside toxicological testing may further improve safety aspects.

High-efficiency decomposition of eggshell membrane by a keratinase from Meiothermus taiwanensis

Eggshell membrane (ESM), a plentiful biological waste, consists of collagen-like proteins and glycosaminoglycans (GAGs) such as hyaluronic acid (HA). Here we used a keratinase (oeMtaker)-mediated system to decompose ESM. The best reaction condition was established by incubating the solution containing oeMtaker, sodium sulfite, and ESM with a weight ratio of 1:120:600. ESM enzymatic hydrolysate (ESM-EH) showed a high proportion of essential amino acids and type X collagen peptides with 963–2259 Da molecular weights. The amounts of GAGs and sulfated GAGs in ESM-EH were quantified as 6.4% and 0.7%, respectively. The precipitated polysaccharides with an average molecular weight of 1300–1700 kDa showed an immunomodulatory activity by stimulating pro-inflammatory cytokines (IL-6 and TNF-α) production. In addition, a microorganism-based system was established to hydrolyze ESM by Meiothermus taiwanensis WR-220. The amounts of GAGs and sulfated GAGs in the system were quantified as 0.9% and 0.1%, respectively. Based on our pre-pilot tests, the system shows great promise in developing into a low-cost and high-performance process. These results indicate that the keratinase-mediated system could hydrolyze ESM more efficiently and produce more bioactive substances than ever for therapeutical applications and dietary supplements.

Atomic Details of Biomineralization Proteins Inspiring Protein Design and Reengineering for Functional Biominerals

Biominerals are extraordinary materials that provide organisms with a variety of functions to support life. The synthesis of biominerals and organization at the macroscopic level is a consequence of the interactions of these materials with proteins. The association of biominerals and proteins is very ancient and has sparked a wealth of research across biological, medical and material sciences. Calcium carbonate, hydroxyapatite, and silica represent widespread natural biominerals. The atomic details of the interface between macromolecules and these biominerals is very intriguing from a chemical perspective, considering the association of chemical entities that are structurally different. With this review I provide an overview of the available structural studies of biomineralization proteins, explored from the Protein Data Bank (wwPDB) archive and scientific literature, and of how these studies are inspiring the design and engineering of proteins able to synthesize novel biominerals. The progression of this review from classical template proteins to silica polymerization seeks to benefit researchers involved in various interdisciplinary aspects of a biomineralization project, who need background information and a quick update on advances in the field. Lessons learned from structural studies are exemplary and will guide new projects for the imaging of new hybrid biomineral/protein superstructures at the atomic level.

Highly efficient engineered waste eggshell-fly ash for cadmium removal from aqueous solution

Sustainable waste and water management are key components of the newest EU policy regarding the circular economy. Simple, performant and inexpensive water treatment methods based on reusing waste are prerequisites for human health, sustainable development and environmental remediation. The design of performant, cost-effective absorbents represents a topical issue in wastewater treatment. This study aimed to investigate the development of a newly engineered adsorbent by functionalizing two different types of waste (industrial and food) with magnetic nanoparticles as environmentally friendly, highly efficient, cheap material for cadmium removal from aqueous solutions. This nano-engineered adsorbent (EFM) derived from waste eggshell and fly ash was used to remove the cadmium from the aqueous solution. SEM analysis has demonstrated that magnetite nanoparticles were successfully loaded with each waste. In addition, was obtained a double functionalization of the eggshell particles with ash and magnetite particles. As a result of this, the EFM surface area substantially increased, as confirmed by BET. A comprehensive characterization (BET, FT-IR, SEM, XRD and TGA) was performed to study the properties of this newly engineered adsorbent. Batch experiments were conducted to investigate the influence of different reaction parameters: temperature, pH, contact time, dosage adsorbent, initial concentration. Results showed that cadmium adsorption reached equilibrium in 120 min., at pH 6.5, for 0.25 g of adsorbent. The maximum efficiency was 99.9%. The adsorption isotherms research displayed that the Cd²⁺ adsorption fitted on the Freundlich model indicated a multi-molecular layer adsorption process. In addition, the thermodynamic study (ΔG < 0, ΔH > 0; ΔS > 0) shows that cadmium adsorption is a spontaneous and endothermic process. The adsorbent kinetic study was described with the pseudo-second-order model indicating a chemisorption mechanism. Desorption results showed that the nano-engineered adsorbent (EFM) can be reused. These data confirmed the possibility to enrich relevant theoretical knowledge in the field of waste recovery for obtaining newly designed adsorbents, performant and inexpensive for wastewater remediation.

Randomised Clinical Trial to Analyse the Efficacy of Eggshell Membrane to Improve Joint Functionality in Knee Osteoarthritis

Osteoarthritis is a source of chronic pain and disability. Dietary supplements have been shown to be a more secure option than NSAIDS. Particularly, the eggshell membrane has demonstrated efficacy in relieving joint pain and stiffness. A clinical trial was designed in which three groups were assigned to two different doses of this supplement and compared to a placebo control group. The primary outcome variable was knee pain, which was assessed using a visual analogue scale. Secondary outcome variables were knee functional ability, quadriceps muscle strength (assessed by isometric and isokinetic trials), and quality of sleep. All groups showed a significant decrease in pain perception, although maximum values were obtained in the high-dose group. Isokinetic and isometric trials showed a significant increase in strength in the high-dose group. Eggshell membrane showed the potential to reduce pain and stiffness symptomatology. Here, for the first time, two quantitative variables (mobility and strength of knee joint) were used to accurately evaluate changes in the quality of life of subjects affected by knee joint pain. The results of this study indicate a dose-dependent response, which should be taken into account for later use in therapeutics to establish the correct dosage.

Recent advances in green processing technologies for valorisation of eggshell waste for sustainable construction materials

Eggshell waste is among of the most abundant agro-waste material discharged from food processing industries. Despite the exceptional properties and several applications, eggshell is castoff in huge quantity without any further use. This review paper focuses on appraising the potential uses of eggshell waste as a feedstock for production of sustainable construction materials. The emphasis is on the need to exploit extensively eggshell waste as a partial cement replacement material in clay and cement-based construction materials. The physical-chemical properties of eggshell powder which describe its unique characteristics are discussed. The exploitation of eggshell waste in various construction materials have resulted into an overall improvement in the physical-mechanical properties. The results from reviewed work show that, the incorporation of 5–30 % of eggshell powder has developed green sustainable construction materials with properties that are within the range for the established engineering standards. In the current paper, it was indicated that the valorisation of eggshell waste has a potential to replace cement material for production of cheap and sustainable construction materials with improved engineering properties. Based on circular economy, valorisation is regarded to be a cost-effective solution to provide eco-friendly industrial raw materials while ensuring a waste free environment in the future.

Biowaste- and nature-derived (nano)materials: Biosynthesis, stability and environmental applications

Due to the environmental pollution issues and the supply of drinking/clean water, removal of both inorganic and organic (particularly dyes, nitroarenes, and heavy metals) to non-dangerous products and useful compounds are very important transformations. The deployment of sustainable and eco-friendly nanomaterials with exceptional structural and unique features such as high efficiency and stability/recyclability, high surface/volume ratio, low-cost production routes has become a priority; nonetheless, numerous significant challenges/restrictions still remained unresolved. The immobilization of green synthesized metal nanoparticles (NPs) on the natural materials and biowaste generated templates have been analyzed widely as a greener approach due to their environmentally friendly preparation methods, earth-abundance, cost-effectiveness with low energy consumption, biocompatibility, as well as adjustability in various cases of biomolecules as bioreducing agents. Natural and biowaste materials are widely considered as important sources to fabricate greener and biosynthesized types of metal, metal oxide, and metal sulfide nanomaterials using plant extracts. Integrating green synthesized nanoparticles with various biotemplates offers new practical composites for mitigating environmental challenges. In this review, degradation of dyes, reduction of toxic nitrophenols, absorption of heavy metals, and other hazardous/toxic environmental pollutants from contaminated water bodies using biowaste- and nature-derived nanomaterials are highlighted.

Waste-derived biomaterials as building blocks in the biomedical field

Recent developments in the biomedical arena have led to the fabrication of innovative biomaterials by utilizing bioactive molecules obtained from biological wastes released from fruit and beverage processing industries, and fish, meat, and poultry industries. These biological wastes that end up in water bodies as well as in landfills are an affluent source of animal- and plant-derived proteins, bio ceramics and polysaccharides such as collagens, gelatins, chitins, chitosans, eggshell membrane proteins, hydroxyapatites, celluloses, and pectins. These bioactive molecules have been intricately designed into scaffolds and dressing materials by utilizing advanced technologies for drug delivery, tissue engineering, and wound healing relevance. These biomaterials are environment-friendly, biodegradable, and biocompatible, and show excellent tissue regeneration attributes. Additionally, being cost-effective they can reduce the burden on the healthcare system as well as provide a sustainable solution to waste management. In this review, the current trends in the utilization of plant and animal waste-derived biomaterials in various biomedical fields are considered along with a separate section on their applications as xenografts.

Preparation and Characterization of Antibacterial Films with Eggshell-Membrane Biopolymers Incorporated with Chitosan and Plant Extracts

A series of films containing chitosan (CS), eggshell membrane (ESM), soluble eggshell membrane (SEP), and plant extracts from Thymus vulgaris and Origanum valgare were prepared with varying concentrations and compositions. These novel films were characterized extensively with respect to film thickness and uniformity, solution absorption, degradation, microenvironmental pH, and antibacterial properties. All the films were flexible with appropriate mechanical stability. After 48 h of soaking in a lysozyme solution, all the films degraded 64 ± 4%, which would be expected to allow for the release of the plant extracts. The plant extracts on their own showed a pH of approximately 4, with the blended films having microenvironmental pHs from approximately 6.4–7.0, which would be expected to promote wound healing. A CS-ESM-SEP film with 5% of each plant extract inhibited almost all E. coli growth in liquid cultures and had no detriments to fluid absorption. Fluid absorption was approximately 100–150% by weight for all the films. The incorporation of SEP and plant extracts to a CS-ESM film provides a promising and novel method for the incorporation of SEP and antibacterial agents in a film with no detriment to wound fluid absorption or film degradation.

Avian Eggshell Membrane as a Novel Biomaterial: A Review

The eggshell membrane (ESM), mainly composed of collagen-like proteins, is readily available as a waste product of the egg industry. As a novel biomaterial, ESM is attractive for its applications in the nutraceutical, cosmetic, and pharmaceutical fields. This review provides the main information about the structure and chemical composition of the ESM as well as some approaches for its isolation and solubilization. In addition, the review focuses on the role and performance of bioactive ESM-derived products in various applications, while a detailed literature survey is provided. The evaluation of the safety of ESM is also summarized. Finally, new perspectives regarding the potential of ESM as a novel biomaterial in various engineering fields are discussed. This review provides promising future directions for comprehensive application of ESM.

Review on the extraction of calcium supplements from eggshells to combat waste generation and chronic calcium deficiency

When faced with a plethora of issues, the possibility of one problem becoming the solution of another is a rare, yet beneficial scenario. This report explores the prospect of viewing the accumulation of organic waste matter in India as a potential calcium reservoir to relieve the issue of calcium deficiency in the population. Waste generation has seen gradual growth, and it has created a problem of waste disposal. A large segment of the generated waste primarily consists of food waste which contains significant amounts of nutrients. Food waste such as eggshells, waste from shellfish, bones, and fish scales contain good amounts of bioavailable calcium, and large quantities of this discarded bioavailable calcium remain unused. Global studies show India to have significantly lower levels of calcium intake than the global average, thus increasing the risk of calcium deficiency-related diseases. Furthermore, research shows that for over the past half of the century, the intake of dietary calcium has declined drastically throughout India. This has led to chronic calcium deficiency-related diseases throughout most of the Indian population. Hence, development of calcium supplements from calcium-rich waste material has the potential to not only reduce the strain on waste management, but also to provide the calcium-deficient population with a cheaper alternative to traditional supplements. Owing to the abundance and ease of separation, eggshells have been chosen as the focus of the review. This review highlights and compares their extraction methods of providing cheap calcium supplements while reducing the amount of eggshell waste.

Physico-mechanical comparative study on gamma irradiated high density polyethylene/eggshell and commercial calcium carbonate composites

Chicken eggshell powder (ESP) as natural source of CaCO3 was incorporated as natural filler into High Density Polyethylene (HDPE).This natural source can be considered as an effective alternative for the commercial calcium carbonate (CC) filler. Characterization of ESP and CC was investigated by FTIR and XRD analysis. HDPE composites filled with 30 phr (ESP) and (CC) were prepared using internal mixer. 2 phr maleic anhydride (MA) was added as compatibilizing agent to HDPE/ESP composite. The prepared composites were vulcanized by using γ-radiation at doses from 50 to 150 kGy. Mechanical and flame retardancy properties of all composites were investigated; composites were thermally analyzed using TGA and DSC. The results showed that, the mechanical properties of HDPE decrease by incorporation of ESP or CC into it, as it was noticed that the mechanical properties of HDPE/ESP composite were better than the mechanical properties of HDPE/CC composite. Moreover, addition of MA led to improvement in mechanical properties of the HDPE/ESP composite. As well, the thermal stability and flame retardancy of the composites increased by adding ESP or CC to HDPE. The results were proved by scanning electron microscopy (SEM).

Eggshell membranes coated chitosan decorated with metal nanoparticles for the catalytic reduction of organic contaminates

This study focusses on the effect of chitosan coating with eggshell membranes for the reduction of different organic pollutants. Chickens eggs were collected from the local market and utilized to extract the enrich eggshell membranes (ESM). The chicken eggshell membranes are abundant waste material which is inexpensive and illustrates remarkable physiognomies for many possible applications. Fresh fibers/strips coated by chitosan (CS) were prepared by mixing the eggshell membranes with CS solution (2 wt%/v) in different proportions i.e., 10 %, 30 %, 50 %, 60 %, 70 %, 80 %, and 90 %. These strips were then templated with copper and iron metal nanoparticles by putting them in their metal ions aqueous solution to adsorb the metals ions and were then reduced to zero-valent metal nanoparticles (MNPS) by using NaBH₄ aqueous solution. These prepared materials (MNPS@ESM-CS) were characterized by using XRD, XPS, FE-SEM, and EDS to confirm the successful preparation of MNPs over the surface of ESM coated with CS. Afterwards, these prepared materials were investigated as a catalyst for the reduction of different organic pollutants, such as 4-nitroaniline (4-NA), 4-nitrophenol (4-NP) and methylene blue (MB) dye. The catalytic efficiency of ESM was enhanced 5.7-fold by adding only 20 % CS solution. It was observed that Cu@ESM-CS-80 % took 7 min for reduction of 4-NA, 6 min for 4-NP, and 7 min for MB dye. The reusability of the catalytic strip was also investigated for four cycles and found efficient and can be easily recovered by simply pulling it from the reaction mixture.

State-of-the-Art of Eggshell Waste in Materials Science: Recent Advances in Catalysis, Pharmaceutical Applications, and Mechanochemistry

Eggshell waste is among the most abundant waste materials coming from food processing technologies. Despite the unique properties that both its components (eggshell, ES, and eggshell membrane, ESM) possess, it is very often discarded without further use. This review article aims to summarize the recent reports utilizing eggshell waste for very diverse purposes, stressing the need to use a mechanochemical approach to broaden its applications. The most studied field with regards to the potential use of eggshell waste is catalysis. Upon proper treatment, it can be used for turning waste oils into biodiesel and moreover, the catalytic effect of eggshell-based material in organic synthesis is also very beneficial. In inorganic chemistry, the eggshell membrane is very often used as a templating agent for nanoparticles production. Such composites are suitable for application in photocatalysis. These bionanocomposites are also capable of heavy metal ions reduction and can be also used for the ozonation process. The eggshell and its membrane are applicable in electrochemistry as well. Due to the high protein content and the presence of functional groups on the surface, ESM can be easily converted to a high-performance electrode material. Finally, both ES and ESM are suitable for medical applications, as the former can be used as an inexpensive Ca2+ source for the development of medications, particles for drug delivery, organic matrix/mineral nanocomposites as potential tissue scaffolds, food supplements and the latter for the treatment of joint diseases, in reparative medicine and vascular graft producing. For the majority of the above-mentioned applications, the pretreatment of the eggshell waste is necessary. Among other options, the mechanochemical pretreatment has found an inevitable place. Since the publication of the last review paper devoted to the mechanochemical treatment of eggshell waste, a few new works have appeared, which are reviewed here to underline the sustainable character of the proposed methodology. The mechanochemical treatment of eggshell is capable of producing the nanoscale material which can be further used for bioceramics synthesis, dehalogenation processes, wastewater treatment, preparation of hydrophobic filters, lithium-ion batteries, dental materials, and in the building industry as cement.

A new bioremediation method for removal of wastewater containing oils with high oleic acid composition: Acinetobacter haemolyticus lipase immobilized on eggshell membrane with improved stabilities

As a result of the increasing demand for edible oils, which are an important part of human nutrition, in recent years, serious environmental problems may arise both during the production and after consumption of these oils.

Eggshell Membrane/Gellan Gum Composite Hydrogels with Increased Degradability, Biocompatibility, and Anti-Swelling Properties for Effective Regeneration of Retinal Pigment Epithelium

A gellan gum (GG) hydrogel must demonstrate a number of critical qualities—low viscosity, degradability, desirable mechanical properties, anti-swelling properties, and biocompatibility—in order to be regarded as suitable for retinal pigment epithelium (RPE) regeneration. In this study, we investigated whether the application of an eggshell membrane (ESM) to a GG hydrogel improved these critical attributes. The crosslinking of the ESM/GG hydrogels was most effectively reduced, when a 4 w/v% ESM was used, leading to a 40% less viscosity and a 30% higher degradation efficiency than a pure GG hydrogel. The compressive moduli of the ESM/GG hydrogels were maintained, as the smaller pores formed by the addition of the ESM compensated for the slightly weakened mechanical properties of the ESM/GG hydrogels. Meanwhile, due to the relatively low hydrophilicity of ESM, a 4 w/v% ESM enabled an ESM/GG hydrogel to swell 30% less than a pure GG hydrogel. Finally, the similarity in components between the ESM and RPE cells facilitated the proliferation of the latter without any significant cytotoxicity.

Eggshell membrane as feedstock in enzyme immobilization

Eggshell membrane, an eco-compatible, safe and cheap by-product was employed as carrier for the laccase from Trametes versicolor immobilization. In order to evaluate the best protocol to apply for the syringic acid degradation, two different types of laccase loading on eggshell membrane were used by incubation in solution or by enzyme-dropping. Chemicals (covalent) and physicals (adsorption) immobilizations were tested for both procedure using native or periodate-oxidized laccase. It is shown that immobilization of periodate-oxidized laccase on NiCl₂-pretreated eggshell membrane was the best method for the first procedure (immobilized activity 1300 U/Kg, a residual activity of 30 % for 6 reuse). For the enzyme-dropping protocol a covalent method with the bifunctional cross linker (glutaraldehyde) was the best method (immobilized activity 3500 U/Kg, a residual activity of 45 % for 6 reuse).

Biologically active components in by-products of food processing

Food by-products happen at various stages of production and processing at home and on commercial scales. In the recent years, because of the fast-growing food companies and production, food processing by-products have gained a lot of interest and attracted many technical and health professionals as well as policy makers internally and internationally. Also, concerns are increasing about food by-products due to their ecological and environmental impact on the planet. This is particularly of concern when large companies emit. Large quantities of food by-products are thrown into environment in which they can be exploited technically, medicinally, and pharmaceutically. This is due to their chemical component and biologically active compounds of the by-products. Therefore, this systematic review focuses on the food by-product biological compounds present in different parts of the food products, particularly in some common foods such as fruits, vegetables, cereals, dairy products, meat, eggs, nuts, coffee, and tea. Moreover, the review also explains the kind of biologically active compounds and their quantity not just in edible foods, but also in part and types of the by-product which then can be reused and recycled into different processes in order to extract and get benefit from.

Identification of Age-Specific and Common Key Regulatory Mechanisms Governing Eggshell Strength in Chicken Using Random Forests

In today's chicken egg industry, maintaining the strength of eggshells in longer laying cycles is pivotal for improving the persistency of egg laying. Eggshell development and mineralization underlie a complex regulatory interplay of various proteins and signaling cascades involving multiple organ systems. Understanding the regulatory mechanisms influencing this dynamic trait over time is imperative, yet scarce. To investigate the temporal changes in the signaling cascades, we considered eggshell strength at two different time points during the egg production cycle and studied the genotype-phenotype associations by employing the Random Forests algorithm on chicken genotypic data. For the analysis of corresponding genes, we adopted a well established systems biology approach to delineate gene regulatory pathways and master regulators underlying this important trait. Our results indicate that, while some of the master regulators (Slc22a1 and Sox11) and pathways are common at different laying stages of chicken, others (e.g., Scn11a, St8sia2, or the TGF- β pathway) represent age-specific functions. Overall, our results provide: (i) significant insights into age-specific and common molecular mechanisms underlying the regulation of eggshell strength; and (ii) new breeding targets to improve the eggshell quality during the later stages of the chicken production cycle.

A Nondestructive Eggshell Thickness Measurement Technique Using Terahertz Waves

Eggshells play a number of important roles in the avian and reptile kingdom: protection of internal contents and as a major source of minerals for developing embryos. However, when researching these respective roles, eggshell thickness measurement remains a bottleneck due to the lack of a non-destructive measurement techniques. As a result, many avian and reptile research protocols omit consideration of eggshell thickness bias on egg or embryo growth and development. Here, we validate a non-destructive method to estimate eggshell thickness based on terahertz (THz) reflectance spectroscopy using chicken white coloured eggs. Since terahertz waves are reflected from outer air-eggshell interface, as well as the inner eggshell-membrane boundary, the resulting interference signals depend on eggshell thickness. Thus, it is possible to estimate shell thickness from the oscillation distance in frequency-domain. A linear regression-based prediction model for non-destructive eggshell thickness measurement was developed, which had a coefficient of determination (R²) of 0.93, RMSEP of 0.009, RPD of 3.45 and RER 13.67. This model can estimate eggshell thickness to a resolution of less than 10 μm. This method has the potential to expand the protocols in the field of avian and reptile research, as well as be applied to industrial grading of eggs.

Reproductive management of poultry

Based on data from the UN's Food and Agricultural Organization, about 120 million metric tons of poultry meat were produced globally in 2016. In addition, about 82 million metric tons of eggs were produced. One of the bases for this production is the reproductive efficiency of today's poultry. This, in turn, is due to their inherent reproductive physiology, intensive genetic selection and advances in husbandry/management. The system of reproduction in males in largely similar to that in mammals except that there is no descent of testes. In females, there are marked differences with there being a single ovary and oviduct; the latter being the name of the differentiated entire Müllerian duct. Moreover, females produce eggs with a yolky oocyte surrounded by albumen, membranes and shell. Among the most successful reproductive management techniques are optimizing photoperiod, light intensity and nutrition. Widespread employment of these has allowed maximizing production. Laying hens can be re-cycled toward the end egg production. Other aspects of reproductive management in poultry include the following: artificial insemination (almost exclusively employed in turkeys) and approaches to reduce broodiness together with cage free (colony), conventional, enriched and free-range systems.

Study on adsorption of Congo red onto chemically modified egg shell membrane

Consumption of eggs leads to generation of huge amount of waste in the form of egg shell, which consists of calcined shell and fibrous membrane. In this study, egg shell membrane (ESM) were chemically modified and used to adsorb congo red from its synthetic aqueous solution. Fourier Transform Infra-red (FTIR) spectra confirmed the presence of hydroxyl, carbonyl and methylene groups in egg shell membrane. Scanning Electron Micrographs (SEM) were also performed to characterize the modified egg shell membrane. Concentration of congo red was measured by using UV spectrophotometer. Effects of various parameters such as initial pH, ESM dosage, contact time and initial congo red concentration were investigated. Highest percentage of adsorption (98%) was obtained at pH 4.5 at a solid to liquid ratio of 1 g-100 ml of congo red solution of concentration of 100 mg/l. Pseudo-second order kinetic model was the best fitted model for this study. The reaction rate constant was found to be 58.04 × 10^-3 g mg^-1·min^-1. The adsorption mechanism was supposed to happen via film diffusion as well as via intraparticle diffusion. Langmuir isotherm gave a better fit for the adsorption compared to the Freundlich isotherm. The maximum monolayer adsorption capacity was determined to be 117.65 mg/g. Thermodynamic parameters (ΔG, ΔH and ΔS) were also studied in this work. The change in enthalpy and change in entropy was found to be 29.217 kJ/mol and 0.124 kJ/mol·K, respectively. The values of ΔG were found to become more negative with increasing temperature.

Sunlight-Driven Photothermal Effect of Composite Eggshell Membrane Coated with Graphene Oxide and Gold Nanoparticles

Eggshell membrane (ESM), which consists of unique interwoven shell membrane fibers, provides a unique supporting platform for functional nanoparticles in catalysis and sensing. This work reports a novel strategy for fabricating sunlight-driven photothermal conversion composite membranes by loading graphene oxide (GO) and gold nanoparticles (AuNPs) on the three-dimension (3D) network structured eggshell membrane. Surface morphologies and chemical elements were characterized by scanning electron microscopy and X-ray photoelectron spectroscopy. High photothermal conversion under simulated sunlight irradiation, which may be caused by the synergistic effect of GO and AuNPs, was achieved by coating both GO and AuNPs onto ESM. The temperature of ESM modified with AuNPs, and then GO increased from 26.0 °C to 49.0 °C after 10 min of light irradiation. Furthermore, the nanoscaled GO and AuNPs could add benefit to the heating localization of the obtained composite membrane. It is expected this biocompatible ESM modified with GO and AuNPs would have great potential in drug release and photothermal therapy applications.

Fire Protection Performance and Thermal Behavior of Thin Film Intumescent Coating

This paper presents the heat release characteristics, char formation and fire protection performance of thin-film intumescent coatings that integrate eggshell (ES) as an innovative and renewable flame-retardant bio-filler. A cone calorimeter was used to determine the thermal behavior of the samples in the condensed phase in line with the ISO 5660-1 standard. The fire resistance of the coatings was evaluated using a Bunsen burner test to examine the equilibrium temperature and formation of the char layer. The fire propagation test was also conducted according to BS 476: Part 6. On exposure, the samples X, Y, and Z were qualified to be Class 0 materials due to the indexes of fire propagation being below 12. Samples Y and Z reinforced with 3.50 wt.% and 2.50 wt.% of ES bio-filler, respectively, showed a significant improvement in reducing the heat release rate, providing a more uniform and thicker char layer. As a result, the addition of bio-filler content has proven to be efficient in stopping the fire propagation as well as reducing the total heat released and equilibrium temperature of the intumescent coatings.

Bio-waste chicken eggshells to store energy

Bio-waste in the form of chicken eggshells, which contain high amounts of calcium carbonate (CaCO3), is used to store energy. The fine eggshell powders are used as an electrode against a metallic lithium anode in a non-aqueous electrolyte. The initial discharge capacitance of the eggshell system was found to be 232 F g-1, while the reversible capacitance was 120 F g-1. Thereon, the cell maintained an excellent capacitance retention of 92% over 1000 cycles. The electrochemical performance obtained is comparable to that of commercially available classical activated carbon (AC) material. CaCO3 showed a non-faradaic behaviour and the shape of the electrochemical curves resembles that of the AC electrode. The preliminary findings suggest that CaCO3 from eggshells can be used as the electrode in Li-ion capacitors to store and release charges effectively over a wide electrochemical stability window of 4 V. Using chicken eggshells in this manner not only reduces the amount of bio-waste, but also adds considerable value. A detailed understanding of the electrochemical and physical behaviour of the material is needed in order to improve its performance and to enable its widespread use.

The Microneurosurgical Training Model for Intrinsic and Extrinsic Brain Tumor Surgery Using Polyurethane Foam and Fresh Cadaveric Cow Brain: An Experimental Study

Objective

To evaluate the feasibility of an experimentally designed brain tumor model consisting of polyurethane foam and fresh cadaveric cow brain for the surgical training of the technique for tumor ablation.

Methods

A laboratory-training model was created for microneurosurgical intervention of intrinsic brain tumor ablation covering microdissection of the brain tissue and opening of the pia mater, dissection and separation of the sulcal and cisternal structures, and dissection and removal of the tumor tissue. The left front parietal lobe was used as the area of interest for this experimental study. One-centimeter cube polyurethane foam was injected 2-cm deep inside the brain tissue using a plastic injection tube. After 5 minutes, the model was ready to use under the operating microscope for dissection, separation, and removal of the tumor tissue. The compatibility of the training model also was evaluated as poor, acceptable, and perfect.

Results

Ten stripped fresh cadaveric cow brains were used in this experimental feasibility study. The compatibility of the model was evaluated as poor, acceptable, and perfect in 1, 6, and 3 subjects, respectively.

Conclusions

In intrinsic brain tumor ablation, surgical manipulations of sulcal, cisternal, and fissural dissection must be undertaken while preserving vital neural and vascular structures. We believe that our model holds promise in developing the technical skills of neurosurgeons in training.

Bio-compatible organic humidity sensor based on natural inner egg shell membrane with multilayer crosslinked fiber structure

In this paper, we propose a novel bio-compatible organic humidity sensor based on natural inner egg shell membrane (IESM) with multilayer cross linked fiber structure that can be used as a substrate as well as a sensing active layer. To fabricate the proposed sensors, two different size inter digital electrodes (IDEs) with 10 mm × 4 mm for sensor 1 and 12 mm × 6 mm for sensor 2 are printed on the surface of the IESM through Fujifilm Dimatix DMP 3000 inkjet material printing setup, which have finger width of 100 μm and space of 100 μm. The fabricated sensors stably operates in a relative humidity (RH) range between 0% RH to 90% RH, and its output impedance and capacitance response are recorded at 1 kHz and 10 kHz. The response time (T_res) and recovery time (T_rec) of sensor 1 are detected as ~1.99 sec and ~8.76 sec, respectively and the T_res and T_rec of sensor 2 are recorded as ~2.32 sec and ~9.21 sec, respectively. As the IESM for the humidity sensor, the natural materials can be implemented in our daily life as they open a new gate way for bio-compatible devices.

Eggshell particle-reinforced hydrogels for bone tissue engineering: an orthogonal approach

Eggshell microparticle-reinforced hydrogels have been fabricated and characterized to obtain mechanically stable and biologically active scaffolds that can direct the differentiation of cells.

Biomineralization in modern avian calcified eggshells: similarity versus diversity

Avian eggshells are composed of several layers made of organic compounds and a mineral phase (calcite), and the general structure is basically the same in all species. A comparison of the structure, crystallography, and chemical composition shows that despite an overall similarity, each species has its own structure, crystallinity, and composition. Eggshells are a perfect example of the crystallographic versus biological concept of the formation and growth mechanisms of calcareous biominerals: the spherulitic-columnar structure is described as "a typical case of competitive crystal growth", but it is also said that the eggshell matrix components regulate eggshell mineralization. Electron back scattered diffraction (EBSD) analyses show that the crystallinity differs between different species. Nevertheless, the three layers are composed of rounded granules, and neither facets nor angles are visible. In-situ analyses show the heterogeneous distribution of chemical elements throughout the thickness of single eggshell. The presence of organic matrices other than the outer and inner membranes in eggshells is confirmed by thermograms and infrared spectrometry, and the differences in quality and quantity depend on the species. Thus, as in other biocrystals, crystal growth competition is not enough to explain these differences, and there is a strong biological control of the eggshell secretion.

Thermo-chemical modification of a natural biomembrane to induce mucoadhesion, pH sensitivity and anisotropic mechanical properties

In the present study due to the distinctive mechanochemical/biological characteristics of natural biomembranes, we state the preparation, characterization and cytocompatibility of modified eggshell membrane (ESM) by citric acid (CA) for biomedical and pharmaceutical applications. FTIR spectroscopy and CHNS analysis demonstrated the successful reaction of ESM with CA. Also, successful modification of the ESM was observed by the change in thermogravimetric analysis. SEM micrographs of neat ESM and ESM-CA gave further insight into membranes morphology and revealed that aligned oriented fibrous frameworks were prepared using thermo-chemical process. The ESM-CA displayed dense and orderly shapes with tailorable architectures to mimic the intended tissue. Moreover, mechanical analyzes for ESM-CA indicated anisotropic mechanical properties and proved that the ESM-CA could induce enhanced mucoadhesion, because of the existence of an enormous amounts of functional groups. It was found that by modification of ESM the swelling behavior was significantly changed. Indomethacin release from the ESM-CA showed enhanced pH sensitivity. The modified membranes have clearly presented adequate mucoadhesion, pH sensitivity and cell viability which can be tailored for potential use in controlled lipophilic drug delivery systems and tissue engineering.

Ball milling of eggshell waste as a green and sustainable approach: A review

Eggshell waste belongs to the most abundant natural waste in nature and is created in huge amounts by everyday consumption of eggs. The majority of this material is being discarded, despite the fact that it has multidisciplinary applications. In this review, the possibility of utilizing the method of ball milling to further broaden the application potential of this material is discussed. The particular application fields include the formation of nanophases, bioceramics synthesis, formation of composites and preparation of material with increased sorption ability. In addition, some other specific applications, like the utilization of ball-milled eggshell as a drug delivery agent, or for the formation of antibacterially active species, are also mentioned. The review provides a critical mechanochemical insight into this topic and aims to emphasize the green and sustainable way of utilizing eggshell waste by environmentally friendly method.

Sexing of chicken eggs by fluorescence and Raman spectroscopy through the shell membrane

In order to provide an alternative to day-old chick culling in the layer hatcheries, a noninvasive method for egg sexing is required at an early stage of incubation before onset of embryo sensitivity. Fluorescence and Raman spectroscopy of blood offers the potential for precise and contactless in ovo sex determination of the domestic chicken (Gallus gallus f. dom.) eggs already during the fourth incubation day. However, such kind of optical spectroscopy requires a window in the egg shell, is thus invasive to the embryo and leads to decreased hatching rates. Here, we show that near infrared Raman and fluorescence spectroscopy can be performed on perfused extraembryonic vessels while leaving the inner egg shell membrane intact. Sparing the shell membrane makes the measurement minimally invasive, so that the sexing procedure does not affect hatching rates. We analyze the effect of the membrane above the vessels on fluorescence signal intensity and on Raman spectrum of blood, and propose a correction method to compensate for it. After compensation, we attain a correct sexing rate above 90% by applying supervised classification of spectra. Therefore, this approach offers the best premises towards practical deployment in the hatcheries.