Hen Eggshell Research Articles

Synthesis Hydroxyapatite from Three Types Eggsshells by Co-Precipitation Method

In the present work, hydroxyapatite (HAp) were synthesised from three types eggshells (hen eggshells, duck eggsshells and quail eggsshells) by co-precipitation method. By using recycled eggshells, there were calcined at 700-900 °C for 2 h to form calcium carbonate (CaCO3). Then, CaCO3 and ammonium dihydrogenphosphate (NH4H2PO4) were used as precursor to produce HAp. The molar ratio of Ca to P was 1.67 : 1. In order to determine the most suitable calcination temperature to produce HAp based on purity of CaCO3, HAp were investigated over the temperatures range of 800-1100 °C for 2 h. Phase formation and microstructure evolution of HAp samples were determined by using (XRD), (SEM) and (FTIR) respectively. The results showed that CaCO3 formed at 700 °C for 2 h of all eggshell types. XRD investigations show that HAp powder were stable up to 1100 °C with hexagonal structure. SEMinvestigations demonstrate that the HAp powder obtained with a sphere morphology and FTIR confirmed that the HAp powder calcined at 1100 °C corresponded to the phosphate group in PO43- with significant characteristic peaks at 1026.5 and 563.9 cm-1.

Optimisation of Activated Carbon Preparation by Chemical Activation of Ayous Sawdust, Cucurbitaceae Peelings and Hen Egg Shells Using Response Surface Methodology

Optimisation of Activated Carbon Preparation by Chemical Activation of Ayous Sawdust, Cucurbitaceae Peelings and Hen Egg Shells Using Response Surface Methodology

Analytical profile of Kukkutanda Tvak Bhasma (incinerated hen egg shells) prepared by two different methods.

Background:Kukkutanda Tvak Bhasma (KTB) (incinerated hen egg shells) is one of the important calcium-rich medicines used to treat leukorrhea, urinary tract infections, etc. Ancient scholars suggested that KTB prepared with processed Hingula (cinnabar) is more potent than Bhasma prepared without Hingula. Hence, in the present study, an attempt has been made to prepare incinerated hen egg shells using two different methods with and without cinnabar and their analytical profiles have been developed.Aims and Objectives:To develop analytical profile of KTB prepared by two different methods.Materials and Methods:Two samples of KTB were prepared. Sample KTB-A was prepared by Kumari Swarasa (juice of Aloe vera Tourn. Linn.) and sample KTB-B was prepared in the presence of Hingula as a medium for Marana using electric muffle furnace. The final product of both the samples of Bhasma were analyzed by organoleptic characteristics, physicochemical parameters and advanced sophisticated instrumental technologies such as particle size detection, inductively coupled plasma-atomic emission spectroscopy, Fourier transfer infrared spectroscopy, X-ray diffraction (XRD) and scanning electron microscopy.Observations and Results:22.75% and 41.16% of Calcium was detected in samples KTB-A and KTB-B, respectively. 0.29% and 0.15% of magnesium was found in samples KTB-A and KTB-B respectively. Both the samples of Bhasma were found to contain calcium hydroxide Ca(OH)2.Conclusions:Minimum four Puta (incineration cycles) with average 800°C temperature is required to prepare KTB through electric muffle furnace using Kumari Swarasa and processed Hingula as a medium. An average particle size was found as 9.35 μm and 9.97 μm in samples KTB-A and KTB-B, respectively. XRD study reveals that raw Kukkutanda Tvak is CaCO3 (calcite) and CaCO3 (calcium carbonate) whereas both the Bhasma contain CaH2O2 (portlandite syn) and Ca(OH)2.

Removal of Phosphates from Water Using Eggshell Bio Sorbents

The present study focuses on the preparation and use of biosorbents produced from eggshells. Hen eggshells are produced as a by-product in large quantities by food manufacturers. The costs associated with eggshell disposal (mainly on landfill sites) are significant and expected to continue increasing as landfill taxes increase.The environmental significance of phosphorus arises from its role as a major nutrient for both plants and microorganisms. The adsorption efficiency of phosphate ions from the obtained biosorbents - raw eggshell powders - is studied at room temperature in static conditions. The effect of phosphate concentration and sorbent mass on the efficiency of the process is evaluated, as well as sorption kinetics are investigated. The structure, phase composition, porosity, specific surface area and morphology of obtained biosorbents is determined. The utilization of eggshells as an abundant, cheap and biodegradable material for the removal of phosphates is studied and discussed.

Biocide Tolerance and Antibiotic Resistance in Salmonella Isolates from Hen Eggshells

The aim of the present study was to determine biocide tolerance and antibiotic resistance in Salmonella isolates from hen eggshells. A total of 39 isolates from hen eggshells, identified as either Salmonella spp. or Salmonella enterica according to 16S rDNA sequencing, were selected for biocide tolerance. Isolates with minimum inhibitory concentrations (MICs) above the wild-type MICs were considered to be biocide tolerant: benzalkonium chloride (BC, 7.7%), cetrimide (CT, 7.7%), hexadecylpyridinium chloride (HDP, 10.3%), triclosan (TC, 17.9%), hexachlorophene (CF, 30.8%), and P3-oxonia (OX, 25.6%). The resulting 21 biocide-tolerant isolates were further characterized. Most isolates (95.2%) were resistant to ampicillin, but only 9.5% were resistant to cefotaxime as well as to ceftazidime. Resistance to chloramphenicol (61.9%), tetracycline (47.6%), streptomycin (19.0%), nalidixic acid (28.6%), ciprofloxacin (9.5%), netilmicin (14.3%), and trimethoprim-sulfamethoxazole (38.1%) was also detected. Considering only antibiotics, 66.7% of isolates were multiresistant; furthermore, 90.5% were multiresistant considering antibiotics and biocides combined. Efflux pump and biocide tolerance genetic determinants detected included acrB (95.2%), oqxA (14.3%), mdfA (9.5%), qacA/B (4.8%), and qacE (9.5%). Antibiotic resistance genes detected included blaTEM (14.3%), blaCTXM-2 (4.8%), blaPSE (4.8%), floR (19.05%), tet(A) (9.5%), tet(C) (4.8%), dfrA12 (0.05%), and dfrA15 (0.05%). Significant positive correlations were detected between phenotypic tolerance/resistance to biocides, biocides and antibiotics, and also between antibiotics, suggesting that a generalized use of biocides could co-select antibiotic resistance.

Synthesis of Nanocrystalline Hydroxyapatite Using Eggshell and Trimethyl Phosphate

Background: Recently, the use of synthetic bone graft substitutes has garnered attention and become more popular than tradi- tional methods for reconstructing osseous defects in the fields of orthopedics and maxillofacial surgery. Commercially available hydroxyapatites (HAs) have been widely reported to be eective bone graft substitutes. Unfortunately, they are expensive to pro- duce. Thus, there is a need to develop methods of producing HA bone graft substitutes from inexpensive sources. Objectives: To synthesize nanocrystalline HA using recycled eggshell and trimethyl phosphate. Until date, several phosphate solu- tions have been utilized for this purpose. However, this is for the first time to the best of our knowledge that trimethyl phosphate is used as a source of phosphate to synthesize eggshell-derived HA. Methods: To produce HA, calcined hen's eggshell was used as a source of calcium, and trimethyl phosphate was used as a source of phosphate in a sol-gel method at a controlled temperature. The results were estimated using scanning electron microscopy (SEM) observantion to evaluate surface morphology, X-ray diraction (XRD) to analyze phase composition, and transmission electron mi- croscopy (TEM) to evaluate the shape and size of prepared HA. Micro-chemical analysis was conducted using energy-dispersive X-ray spectroscopy (EDX). Fourier transform infrared spectroscopy (FTIR) was employed to identify the functional groups of the prepared HA. Results: XRD evaluation showed that high-purity synthetic HA powder was obtained. The results of the SEM, XRD, TEM, EDX, and FTIR analyses demonstrated that the synthesis yielded nanostructured HA. Conclusions: A complete synthesis of nanocrystalline HA was obtained by using trimethyl phosphate and eggshells in a sol-gel method at a controlled temperature. A spherical particle morphology and particle size ranged 19 - 41 nm were achieved. Eggshell waste material is inexpensive and can be considered a viable choice for high-volume HA powder production, based on the present results.

Detection of potential pathogenic aerobic bacteria from egg shell and egg contents of hen collected from poultry.

This study was done to identify different pathogenic aerobic bacteria from egg shell and egg contents of hen. Egg shells and egg contents of 150 eggs collected from poultry were tested. Of 150 egg shells, 130 (86.67%) yielded growth of bacteria and 60 (40%) Esch. coli,.25 (16.67%) Providencia rettgeri, 5 (3.33%) Providencia alkalifaciens, 20 (13.33%) Citrobacter freundii, 10 (6.67%) Salmonella spp, 10 (6.67%) Enterobacter aerogenes were isolated. No bacteria were isolated from 150 egg contents. Total 14 (9.33%) Salmonella spp. from egg shells and 7 (4.67%) Salmonella spp. from egg contents were identified by PCR. Most of the identified serotypes were Salmonella Enteritidis (42.86% from egg shells and 71.43% from egg contents). All (100%) Salmonella Typhi and Salmonella Paratyphi A were sensitive to ciprofloxacin and ceftriaxone.

Virulence factors and antimicrobial resistance in Escherichia coli strains isolated from hen egg shells

Eggs may contain extraintestinal pathogenic (ExPEC) and diarrheogenic (DEC) Escherichia coli which in addition may carry antibiotic resistance. The wide use of biocides and disinfectants in the food industry may induce biocide tolerance in bacteria. The aim of the present study was to evaluate biocide tolerance and antibiotic resistance in E. coli from hen egg shells. A total of 27 isolates obtained from a screening of 180 eggs were studied. Seven isolates carried both eae and bfpA genes of typical enteropathogenic E. coli (EPEC) strains, while 14 isolates only carried eae associated with atypical EPEC strains. Shiga toxin genes stx and stx2 were detected in four isolates. Heat-stable and heat-labile enterotoxin genes as well as aggR were also detected. Several isolates had minimum inhibitory concentrations (MICs) that were higher than the wild-type for the biocide hexadecylpyridinium chloride (HDP, 18.52%) or the commercial disinfectant P3 oxonia (OX, 14.81%). Antibiotic resistance was detected for ampicillin (37.03%), streptomycin (37.03%), tetracycline (37.03%), chloramphenicol (11.11%), nalidixic acid (18.51%) and trimethoprim-sulfamethoxazole (14.81%). Eight isolates (29.63%) were biocide tolerant and antibiotic resistant. Efflux pump genes detected included acrB (96.29%), mdfA (85.18%) and oxqA (37.03%), in addition to quaternary ammonium compound (QAC) resistance genes qacA/B (11.11%) and qacE (7.40%). Antibiotic resistance genes detected included blaCTX-M-2 (22.22%), blaTEM (3.70%), blaPSE (3.70%), tet(A) (29.63%), tet(B) (29.63%), tet(C) (7.40%), tet(E) (11.11%), aac(6′)-Ib (3.70%), sul1 (14.81%), dfrA12 (3.70%) and dfrA15 (3.70%). Most isolates (96.30%) carried more than one genetic determinant of resistance. The most frequent combinations were efflux pump components acrB and mdfA with tetracycline resistance genes (33.33% of isolates). Isolates carrying QAC resistance genes also carried between 4 and 8 of the additional antimicrobial resistance genes investigated. Regardless of biocide tolerance and antibiotic resistance, all isolates were sensitive to carvacrol (0.25%), thymol (0.125%) and trisodium phosphate (1 to 1.5%), but they exhibited a heterogeneous response to sodium lactate and lysozyme-EDTA combinations that apparently were not related with antibiotic resistance. Results from the study reveal not only a low incidence of biocide tolerance but also the presence of multiple resistance strains carrying multiple genetic determinants of resistance.

Isolation and Identification of Pathogenic Gram-Positive Bacteria from Egg Shell of Hen and to See Their Antimicrobial Susceptibility Pattern

Background: Food-borne disease is a major public health problem affecting developed as well as developing countries. Inaccurately treated eggs can be one of its causes. So we designed this study to observe the possibility of transmission of pathogenic Gram-positive bacteria from market eggs to the community.Objectives: To identify different Gram-positive bacteria in eggs and to observe their antimicrobial susceptibility.Materials and Methods: This observational study was conducted in the department of Microbiology, Dhaka Medical College, Dhaka. Shells of 150 eggs collected from different markets of Dhaka city were tested. Bacteria were isolated and identified by culture and relevant biochemical tests.Results: Out of 150 egg shells, 120 (80%) yielded growth of different bacteria. Of them, Staphylococcus spp. were 80 (66.67%), Streptococcus spp. 8 (6.67%), Bacillus subtilis 20 (16.67%) and Bacillus cereus 12 (10%). Out of 80 Staphylococcus spp., 30 (25%) were Staphylococcus aureus and 50 (41.67%) were Staphylococcus saprophyticus. Most of the Gram-positive bacteria were sensitive to ciprofloxacin, ceftriaxone and imipenem. No MRSA and VRSA were found.Conclusion: It can be concluded from this study that Gram-positive bacteria from market eggs may be an important source of infection to the community.J Enam Med Col 2016; 6(1): 15-18

Effects of cage and barn rearing system on early laying performance of pullet

The present experiment was conducted with 144 Shaver 579 egg laying pullets to compare their performances reared on barn and in cages for a period of 16 weeks from 25 to 40 weeks of age. Feed consumption, feed conversion (FC) and egg weight were significantly higher when reared on barn than in cages. However, hen day egg production (HDEP), egg mass, body weight, livability, albumen index, Haugh unit (HU), yolk index, shape index and egg shell thickness did not differ (P>0.05) between pullets under two different rearing systems. Soiled eggs (p<0.01) and shell breaking strength (P<0.05) were higher for the pullets reared on barn than in cages. In contrast, yolk color score (YCS) was higher (P<0.05) in eggs collected from the cage-reared pullets when compared with the eggs of pullets reared on barn. It is concluded that egg laying pullets can be reared either on barn or in cages successfully in Bangladesh condition without any adverse effect on egg production.Bang. J. Anim. Sci. 2015. 44 (3):151-156

Development of a biomimetic nanocomposite gradient scaffold to mimic the natural osteochondral structure for tissue repair

Event Abstract Back to Event Development of a biomimetic nanocomposite gradient scaffold to mimic the natural osteochondral structure for tissue repair Cristian Parisi1, 2, Luca Salvatore2, Neelam Gurav1, Marta Madaghiele2, Lucy Di Silvio1 and Alessandro Sannino2 1 King's College London, Tissue Engineering & Biophotonics Division, United Kingdom 2 University of Salento, Department of Engineering for Innovation, Italy Introduction: The natural osteochondral (OC) tissue exhibits a unique gradient structure which varies with distance from the articular cartilage to subchondral bone[1]. In this study, a biomimetic collagen-based scaffold reinforced with nanohydroxyapatite (nHAp) has been developed to obtain an engineered device which mimics the gradient structure of the natural tissue for OC defects repair[1],[2]. Scaffolds were analysed to verify chemical and phase compositions, porosity architecture and mechanical properties. Furthermore, they were seeded with primary human mesenchymal stem cells (hMSCs) and examined for differentiation towards osteo- and chondrogenic lineages[3]. Materials and Methods: Bovine collagen I (Coll) was used as a collagen source. Hydrated CaO from hen eggshell and H3PO4 were used for nHAp synthesis. nHAp was directly nucleated into collagen suspensions and highly porous scaffolds were obtained using a one-step freeze-drying process. FTIR, XRD, SEM, EDS and micro-CT analyses were carried out to check chemical and phase compositions and pores architecture of the scaffold. Mechanical properties were verified by compression and tension tests in wet state. Primary hMSCs were seeded on scaffolds and then conditioned to induce terminal differentiation in osteo- or chondrogenic conditions. Cell proliferation (alamarBlue) and viability (Live&Dead) were verified up to 28 days. The morphology of cells on the scaffolds was evaluated using SEM and fluorescence microscopy. qPCR was used to verify the expression of specific genes for osteo- (ON, RUNX2) and chondrogenic (SOX9, COL2A1) differentiation. Results and Discussion: Physicochemical analyses confirmed that scaffolds were composed of collagen and nHAp, and both materials were chemically integrated with each other. In particular, SEM, EDS and micro-CT showed the gradient distribution of mineral phase and interconnected porosity throughout the scaffold. Compression and tension tests confirmed the mechanical stability of the device and showed improved mechanical properties with the increase of the nHAp content. The gradient scaffold exhibited excellent biocompatibility and allowed cell migration with higher cell proliferation and viability compared to non-gradient nHAp/Coll scaffolds. Cells on the gradient scaffold demonstrated different morphologies after 28 days in osteo- or chondrogenic condition. This was confirmed by qPCR analysis where specific genes (ON, RUNX2, SOX9, COL2A1) showed an upregulation compared to non-gradient scaffolds when kept in osteo- or chondrogenic condition. Conclusion: The biomimetic scaffold was successfully fabricated with a gradient distribution of mineral phase and interconnected porosity throughout the scaffold as desired. The scaffold showed excellent mechanical and biological properties allowing stem cells proliferation and differentiation in osteo- and chondrogenic condition. On the basis of these excellent results, in vivo studies on an animal model (sheep) are currently ongoing.

Sorption dominance of biowaste Camelia sinensis and Gallus domesticus to activated carbon, alumina, and silica

Toxicity of heavy metals to higher life forms is ascribed to mobility and accumulation in water reservoir. Adsorption offers a promising alternative to treat wastewater. This article proposes green and economically viable options for the replacement of expensive commercial adsorbent. The spent Camelia sinensis (black tea) and Gallus domesticus (hen egg shell) powder under identical experimental conditions possesses better sorbing potential for cadmium (Cd) and lead (Pb). The adsorbents can be conveniently regenerated with HCl solution. The proposed adsorbents were found successful in situ remediation of textile, pharmaceutical, and leather industry effluents. Cost benefit and batch sorption analysis strongly recommends the present experimental endeavor for commercial scale up.

Synthesis and Characterization of Collagen Scaffolds Reinforced by Eggshell Derived Hydroxyapatite for Tissue Engineering.

In this work, we synthesized porous nanohydroxyapatite/collagen composite scaffold (nHA-COL), which resemble extracellular matrices in bone and cartilage tissues. Nano hydroxyapatite (nHA) was successfully nucleated in to the collagen matrix using hen eggshell as calcium biogenic source. Porosity was evaluated by apparent and theoretical density measurement. Porosity of all scaffolds was in the range of 95-98%. XRD and TEM analyses show the purity and size of nucleated HA around 10 nm and selected area electron diffraction (SAED) analysis reveals the polycrystalline nature of nucleated HA. SEM analysis reveals (i) all the scaffolds have interconnected pores with an average pore diameter of 130 micron and (ii) aggregates of hydroxyapatite were strongly embedded in the collagen matrix for both composite scaffolds compared with pure collagen scaffold. EDS analysis shows the Ca/P stoichiometric ratio around 1.67 and FTIR reveals the chemical interaction between the collagen molecule and HA particles. The testing of mechanical properties evidenced that incorporation of HA resulted in up to a two-fold increase in compressive modulus with high reinforcement level (-7 kPa for 50HA-50COL) compared to pure collagen scaffold.

Vliv tvaru vajec na rozložení napětí ve vaječné skořápce při zatěžování vnitřním přetlakem

The influence of the eggshell shape on the stress distribution under internal pressure is studied. A mathematical description of the hen's eggshell is proposed. The analytical expressions for the membrane solution are presented. Obtained results are used for the evaluation of a set of domestic hen's eggs. 28 eggs were analysed in this study. The weight of eggs ranged from 49.55 g to 61.08 g, the egg shape ranged from 72.82 % to 84.94 %, the average eggshell thickness ranged from 0.343 to 0.433 mm. The eggshell strength is given namely by the maximum values both of meridian and circumferential forces. The dependence of the meridian force maximum on the egg shape index has some tendency to increase with egg shape index. The outlined linear dependence is very weak, the coefficient of correlation is about 0.45.

The Influence of Biogenic and Synthetic Starting Materials on the Properties of Porous Hydroxyapatite Bioceramics

The aim of this study was to investigate the influence of biogenic and synthetic starting materials on properties of porous hydroxyapatite (HAp) bioceramics. HAp powders were synthesized by modified precipitation method using biogenic calcium carbonates (ostrich (Struthio camelus) egg shells, hen (Gallus gallus domesticus) egg shells, snail (Viviparus contectus) shells) and synthetic calcium oxides (Sigma-Aldrich and Fluka). Specific surface area, molecular structure and morphology of obtained powders were determined. As-synthesized HAp powders had a varied specific surface area with a wide range from 83 to 150 m2g-1 depending on CaO source. Porous bodies of HAp were prepared by in situ viscous mass foaming with NH4HCO3 as pore forming agent. Foamed and dried green bodies were sintered at 1100 °C. The obtained bioceramics were investigated using Archimedes method, field emission scanning electron microscopy and Brunauer-Emmett-Teller method. There are considerable differences between porous HAp bioceramics structures prepared from different sources of CaO. The choice of starting material substantially affects the macro-and microstructure of prepared porous bioceramics.

A new patch material for tympanic membrane perforation by trauma: the membrane of a hen egg shell

Conclusion: The egg shell membrane (ESM) patch may promote tympanic membrane (TM) healing in acute traumatic TM perforation. Objective: To evaluate the use of ESM for treating acute traumatic TM perforation. Methods: We reviewed charts of patients with traumatic TM injury from 2008 to 2011. Treatments were an ESM patch or a perforation edge approximation. We divided patients into two groups according to the treatment used. Each patient was matched by treatment onset and perforation size. We compared healing ratio, healing time, and frequency of otorrhea between the perforation edge approximation group and the ESM patch group. Matched t tests were used for analysis. Results: The healing ratio of the TM showed no significant difference between the two groups, but the time to heal was significantly shorter in the ESM patch group than in the perforation edge approximation group.

Processing of Eggshell Biomaterial by Electrical Discharge Assisted Mechanical Milling (EDAMM) and High Energy Milling (HEM) Techniques

In this study, hen eggshell (ES) biomaterial was treated by two mechanochemical methods. Here we show that using of low-current high-voltage electrical impulses during electrical discharge assisted mechanical milling (EDAMM) or high-energy milling (HEM) are proper tools for ES transformation to materials suitable for the further applications. The decomposition of calcite CaCO3 (the main component of ES) into lime CaO (EDAMM treatment) or calcite-aragonite transformation (HEM treatment) were documented by X-ray diffractometry. The applied techniques bring about solid state transformation, high degree of calcite amorphization, and enhancement of specific surface area of ES samples. As examples of using the transformed ES the uptake of cadmium ions during sorption experiments and the dechlorination of polyvinyl chloride are given. In both cases, the technologically accepted recoveries and kinetics have been obtained.

Solubilization and Identification of Hen Eggshell Membrane Proteins During Different Times of Chicken Embryo Development Using the Proteomic Approach

A fertilized chicken egg is a unit of life. During hatching, transport of nutrients, including calcium, have been reported from the egg components to the developing embryo. Calcium is mobilized from the eggshell with the involvement of Ca(2+)-binding proteins. In addition, other unknown proteins may also play some important roles during embryo developing process. Therefore identification and prediction of biological functions of eggshell membrane (ESM) proteins during chick embryo development was conducted by proteome analysis. Comparison of different lysis solutions indicated that the highest ability to extract ESM proteins could be obtained with 1% sodium dodecyl sulfate in 5mM Tris-HCl buffer pH 8.8 containing 0.1% 2-mercaptoethanol. In this study fertilized Cornish chicken eggs were incubated at 37°C in humidified incubators for up to 21days. At selected times (days 1, 9, 15 and 21), samples were taken and the ESMs were carefully separated by hand, washed with distilled water, and air-dried at room temperature. The ESM proteins were then solubilized and analyzed by proteome analysis. Sodium dodecyl sulfate polyacrylamide gel electrophoresis combined with high performance liquid chromatography and mass spectrometry revealed 62 proteins in the ESM; only keratin is known ESM protein, 8 of which are egg white proteins and related while 53 others have not previously been reported. Some differences in the types of proteins and their molecular functions were noted in ESM at different incubation times. One protein which was present only at days 15 and 21 of egg incubation was identified as a calcium binding protein i.e. EGF like repeats and discoidin I like domain 3 (EDIL3 homologous protein).

Salmonella Infantis, a Potential Human Pathogen has an Association with Table Eggs

Food borne Salmonellosis in human is mainly caused by the consumption of contaminated eggs and other poultry products. Trans-shell route is considered the underlying phenomena leading to the production of Salmonella Infantis contaminated eggs. Salmonella Infantis comes in the top 10 human pathogenic Salmonella serovars, been isolated from human and poultry from diverse group of countries in patients linked to contaminated food. Majority of the Salmonella cases are sporadic, outbreaks occur frequently with a direct or indirect link to contaminated food especially poultry. This review has mainly highlighted the factors affecting Salmonella transmission with a special emphasis on hen eggshell quality.

Synthesis of nanocrystalline hydroxyapatite by precipitation using hen's eggshell

Hydroxyapatite (HAP) is a substance that is most actively used in orthopedia and dentistry as a biocoating of implants in order to improve its osteointegration with bone tissue. HAP was synthesized by precipitation technique with the use of the biological source — hen's eggshell. X-ray diffraction (XRD) investigations, IR-spectroscopy, scanning electron microscopy (SEM) demonstrate that the obtained powder-like material in the form of globules from 4 to 5 μm in size is single-phase, thermally stable up to 900 °C and morphologically uniform. The globules consist of nanocrystals with the average size of about 30 nm.