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BAB 1
PENDAHULUAN
Bab 1 PENDAHULUAN
1.0 PENGENALAN
1.0.1 Fungsi
Cangkerang telur merupakan organ respirasi bagi pertumbuhan embrio melalui pertukaran
gas secara resapan. Struktur asas sosiologi cangkerang telur terbina daripada pelbagai
komponen yang menyediakan permukaan atau lapisan bagi pertukaran gas dan kawalan
osmosis berlaku (Steward, 1935; Simons, 1971; Freeman and Vince, 1974; Parsons, 1982).
1.0.2 Lapisan filem
Lapisan paling dalam ialah lapisan filem nipis yang merupakan lapisan pelindung bagi
cangkerang telur ayam.
1.0.3 Lapisan membran dan lapisan membran palisad
Lapisan filem seterusnya dilapisi oleh lapisan membran cangkerang telur. Bahagian luar
lapisan filem ini dilindungi oleh lapisan vascularized chorioallantois iaitu lapisan yang
paling nipis daripada lapisan membran luar cangkerang telur. Membran luar ini dilapisi oleh
lapisan mammillary (100m) yang mempunyai lapisan teras epitactic bagi formasi kristal
kalsium karbonat, CaCO3 (Creger et al., 1976; Stembergeret al., 1977). Lapisan kristal
CaCO3 terbentuk mencancang di atas bonggol struktur lapisan mammillary membentuk ruang
berbentuk kon di antara lapisan kristal yang terbentuk. Lapisan ini membentuk permukaan
lapisan membran palisad (200m) yang berongga. Sebahagian kecil lapisan ini terdiri
daripada 0.3% fosforus, 0.3% magnesium, dam kuantiti kecil sodium, potassium, zink,
mangan, besi dan kuprum. Hampir 95% daripada cangkerang telur terbina daripada struktur
CaCO3 (kumpulan no. 167: R-3c) atau kira-kira 5.5 g CaCO3 yang terdapat dalam membran
palisad.
1.0.4 Peranan cangkerang telur
Oleh sebab liang yang terdapat dalam cangkerang telur yang sesuai adalah terbentuk di mana
sisi kon atau ruang yang gagal untuk bertemu dengan sama rata. Oleh itu, formasi teras
mammillary dan pembahagiannya adalah berkaitan dengan tenaga mekanikal dan kualiti
proses respirasi yang dikawal oleh cangkerang telur.
1.0.5 Lapisan kutikel
Lapisan paling luar adalah lapisan organik yang melapisi permukaan yang tidak sama rata
iaitu lapisan kutikel (5-8m). Kutikel terbina daripada sebahagian besarnya protein dengan
beberapa polisakarida dan jirim lipid (Baker and Balch, 1970; Board, 1982). Lapisan kutikel
juga menghubungkan lumina dari luar liang cangkerang telur bagi menyediakan laluan untuk
gas resapan (Board and Scott, 1980).
1.1 MASALAH PELUPUSAN CANGKERANG TELUR AYAM
1.1.1 Kajian ADAS
Kajian oleh ADAS dalam industri penghasilan produk telur di United Kingdom pada Mei
2001, telah menyenaraikan masalah-masalah berikutan pelupusan cangkerang telur ayam
khususnya, dalam aspek kos termasuklah dalam masalah pembayaran cukai. Dalam kajian
tersebut, kira-kira 10 000 hingga 11 000 tan cangkerang perlu dilupuskan setiap tahun.
Masalah pelupusan cangkerang telur ayam bukan sahaja berlaku di United Kingdom sahaja
malah di negara-negara lain. Beberapa kajian yang sama dan usaha sama telah dilakukan bagi
mengatasi masalah ini.
1.1.2 Kos dan cukai
Pelupusan cangkerang telur ayam di tapak pelupusan sampah merupakan cara yang paling
murah dari segi kos. Namun, peningkatan cukai bagi tapak pelupusan sampah ini
membuatkan cara ini sebenarnya tidak sesuai pada masa akan datang malah membebankan.
1.1.3 Cukai bahan buangan
Pasukan pencinta alam sedar bahawa penghasilan gas metana, karbon dioksida dan kesan
bahan kimia organik yang reaktif amat bahaya . Oleh itu, kawalanterhadap tapak pelupusan
sampah diperketat. Peraturan di United Kingdom, misalnya di kuatkuasakan kembali. Justeru,
cukai bahanm buangan cangkerang telur ayam terbuang yang mencapai £13 per tan
ditetapkan meningkat sebanyak £1 per tan pada setiap tahun berikutnya. Kos bahan buangan
meningkat mengikut berapa jauh atau berapa lama jarak tapak pelupusan sampah tersebut.
Perubahan kos tersebut antara £15 per tan dan £35 per tan tidak termasuk cukai lain.
1.2 KONKLUSI
Cangkerang telur termasuk dalam ketegori makanan terbuang, minuman atau bahan yang
digunakan atau menjadi sumber dalam penyediaan makanan dan minuman. Kenyataan ini
temasuk dalam The Waste Management Licening Regulations 1994, Statuory Instrument
1994 No. 1056 di United Kingdom. Sifat fizikal cangkerang telur terbuang (serpihan besar )
dapat menghasilakan kapur atau CaCO3 yang sesuai dikitar semula menjadi bahan seramik
dalam bidang agrikultur. Melalui cara ini, masalah pelupusan cangkerang telur ayam yang
tinggi berikutan penggunaan telur ayam dalm penyediaan makanan sangat meluas.
BAB 2
OBJEKTIF KAJIAN
BAB 2 OBJEKTIF KAJIAN
2.0 Mengurangkan kos pelupusan sampah
1.Objektif utama kajian adalah untuk mencari alternatif lain, dalam usaha mengitar
semula cangkerang telur ayam khususnya. Masalah pelupusan bahan buangan
cangkerang telur ayam yang banyak kuantiti penggunaannya, meningkatkan kuantiti
bahan buangan yang perlu dilupuskan malah meningkatkan kos pelupusan sampah.
2.Kira-kira 10 000 hingga 11 000 tan cangkerang telur perlu dilupuskan bukan sahaja
menjadi masalah besar di negara seperti United Kingdom, malah berlaku juga
kepada negara-negara yang lain.
2.1 Mengurangkan gangguan ekosistem
1.Struktur kalsium karbonat, CaCO3 yang terdapat dalam cangkerang telur merupakan
struktur CaC03 yang sama dengan struktur semulajadi CaCO3 dalam batu kapur.
2.Pengasingan membran cangkerang telur ayam untuk mendapatkan lapisan CaC03 ini
dijalankan untuk menghasilkan bahan seramik bagi mengurangkan tarahan atau
gangguan ekosistem di gua batu kapur mahupun struktur lain yang mengandungi
sumber ini.
3.Masalah gangguan ekosistem dapat mengganggu populasi yang hidup dalam
ekosistem tersebut.
2.2 Penghasilan produk seramik yang menjimatkan
1. Melalui kajian ini, penggunaan seramik daripada cangkerang telur dapat digunakan
secara meluas dalam industri pembuatan pinggan dan mangkuk daripada seramik malah
digunakan dalam proses penghasilan jubin lantai yang kini luas permintaannya.
2. Penghasilan produk seramik daripada serbuk daripada cangkerang telur ayam ini
sebenarnya amat berpatutan kerana sumbernya diperoleh daripada sumber yang terbuang.
Maka produk ini amat menjimatkan.
2.3 Memenuhi syarat graduasi
1. Antara syarat keutamaan graduasi adalah melibatkan diri dalam Program Khas
Pendidikan di MRSM Mersing. Syarat ini perlu diikuti bagi mendapatkan sijil
penganugerahan graduasi.
BAB 3
CARA KERJA DAN MASALAH
3.0 MENGENAL PASTI MASALAH
3.0.1 A) Masalah kos pelupusan bahan buangan termasuk cangkerang telur yang tinggi.
B) Masalah gangguan ekosistem di lokasi sumber batu kapur.
C) Masalah kos penghasilan seramik dan kos jualan yang tinggi di samping
permintaan yang luas.
3.1 MERANGKA HIPOTESIS
Sumber kalsium karbonat (CaCO3) dalam struktur cangkerang telur boleh dikitar semula
menjadi bahan seramik yang praktikal.
3.2 MERANCANG PENYIASATAN
A) Pengumpulan maklumat
1. Maklumat tentang struktur cangkerang telur dan masalah yang dihadapi tentang
pelupusan cangkerang telur, kajian terdahulu tentang cangkerang telur, diperoleh daripada
internet dan bahan rujukan di pusat sumber .
B) Pengumpulan cangkerang telur ayam terbuang
1.Pengumpulan dijalankan di beberapa restoran terdekat, yang berhampiran.
2.Proses pengumpulan cangkerang telur ayam terbuang dijalankan dengan memohon
kebenaran telebih dahulu kepada pengurus perniagaan kedai makan.
3.Setiap ahli kumpulan telah berjaya mengumpul lebih kurang 50 keping cangkerang
telur ayam terbuang dalam tempoh sebulan secara keseluruhan.
C) Perancangan awal eksperimen
1.Teori yang digunakan ialah teori kinetik jirim. Teori kinetik jirim menyatakan bahawa
semua jirim terdiri daripada zarah-zarah kecil iaitu atom, ion atau molekul yang
sentiasa berada dalam keadaan bergerak. Semua nirim mempunyai jisim dan
isipadu.
2.Ciri-ciri jirim dalam bentuk pepejal ialah :
a) Jarak antara molekul dan cara susunan molekul rapat dan teratur dan pola susunan yang
tetap.
b) Mempunyai isipadu dan bentuk yang tetap.
c) Ketumpatan yang tinggi.
d) Daya tarikan dan daya tolakan yang kuat.
e) Bergetar pada kedudukan yang tetap sahaja.
f) Ketermampatan yang sangat rendah dan daya tolakan antara molekul yang sangat.
(berdasarkan eksperimen memapatkan plastisin dalam picagari dengan menggerakkan
omboh).
BAB 4
UJIKAJI DAN KEPUTUSAN
BAB 4 UJIKAJI DAN KEPUTUSAN
4.0 EKSPERIMEN – Penghasilan seramik daripada serbuk
cangkerang
telur ayam.
Tujuan : 1. Mengitar semula serbuk cangkerang telur ayam menjadi bahan seramik.
2. Mengkaji hubungan antara jisim serbuk cangkerang telur ayam dengan
nilai kekerasan bahan seramik daripada serbuk cangkerang telur ayam
yang terhasil.
3. Menentukan jisim serbuk cangkerang telur ayam yang paling sesuai untuk
menghasilkan produk seramik yang pelbagai.
Hipotesis : 1. Serbuk cangkerang telur ayam boleh dikitar semula menjadi
bahan seramik.
2. Jisim serbuk CaCO3 cangkerang telur ayam berkadaran terus
dengan nilai kekerasan seramik yang terhasil.
3. Jisim serbuk cangkerang telur ayam yang paling sesuai ialah 16g
kerana ketebalan yang sesuai untuk menghasilkan pelbagai
produk dan mempunyai nilai kekerasan yang tinggi.
Bahan : 40 keping cangkerang telur ayam.
Radas : Mesin penimbang Analytical Balance, mesin pemampat Pellitizing Press,
mangkuk pijar, spatula, mesin penguji kekerasan Rockness Hardness Tester,
ketuhar Purnace EML, forsep, air suling, lesung penggiling dan mesin pengisar.
PROSEDUR
A) Pengasingan membran dan cangkerang telur ayam.
1.40 keping cangkerang telur ayam dikumpulkan dan dibersihkan dengan menggunakan
air suling untuk menyingkirkan benda asing.
2.Lapisan membran cangkerang telur dipisahkan dengan menggunakan forsep. Semua
lapisan membran cangkerang telur ayam dipastikan telah diasingkan.
3.Lapisan cangkerang telur ayam yang telah diasingkan daripada membrannya, dijemur
di bawah sinaran Matahari selama satu jam.
4.Cangkerang telur ayam diramas dengan menggunakan tangan sehingga menjadi
kepingan kasar.
5.Kepingan kasar cangkerang telur ayam dikisar dengan menggunakan mesin pengisar
sehingga menjadi serbuk halus.
6.Masukkan serbuk halus cangkerang telur ayam ke dalam lesung penggiling. Serbuk
halus cangkerang telur ayam tersebut digiling sehingga benar-benar halus.
B) Pemampatan serbuk cangkerang telur ayam di bawah tekanan, suhu dan
tempoh yang tertentu.
1.Serbuk cangkerang telur ayam yang sangat halus dimasukkan ke dalam mangkuk pijar
dengan menggunakan spatula dan 4g serbuk cangkerang telur ayam ditimbang
dengan menggunakan mesin penimbang Analytical Balance.
2.Serbuk cangkerang telur dimasukkan ke dalam mesin pemampat Pellitizing Press
selama 10 minit di bawah tekanan 30 kN.
3.Selepas 10 minit, pepejal serbuk cangkerang telur ayam (seramik) yang terhasil
dipindahkan ke dalam ketuhar yang dilaraskan pada suhu 200C selama 90 minit.
4.Sampel bagi setiap pepejal serbuk cangkerang telur ayam (seramik) dimasukkan yang
terhasil ke dalam bekas yang diasingkan dan dilabel dengan “A”.
5.Langkah 1 hingga langkah 4 diulang dengan menggantikan 7g, 10g, 13g, dan 16g bagi
menggantikan jisim serbuk cangkerang telur ayam dan pepejal cangkerang telur
ayam (seramik) yang terhasil dilabel masing-masing dengan “B”, “C”, “D”, dan
“E”.
C) Menguji kekerasan kepingan sampel pepejal cangkerang telur ayam (seramik)
yang terhasil.
1.Kekerasan pepejal cangkerang telur ayam (seramik) yang terhasil diuji dengan
menggunakan mesin mesin penguji kekerasan Rockness Hardness Tester.
2.Pemerhatian ketebalan dan keadaan mudah pecah sampel dicatatkan dalam jadual.
3.Nilai kekerasan bagi setiap sampel tersebut dicatatkan dalam jadual.
4.Graf jisim serbuk cangkerang telur ayam melawan kekerasan bahan seramik daripada
serbuk cangkerang telur ayam yang terhasil diplotkan.
KEPUTUSAN
Sampel Jisim Nilai kekerasan (Hv) Purata
serbuk
cangkerang
telur ayam
(g)
nilai
kekerasan
(Hv)
Pemerhatian
Bacaan
pertama
Bacaan
kedua
Bacaan
ketiga
Bacaan
keempat
A 4 57.7 78.0 49.0 21.6 51.6 Ketebalan amat tidak sesuai dan sangat mudah pecah
B 7 53.0 51.9 67.1 58.0 57.5 Ketebalan tidak sesuai dan sangat mudah pecah
C 10 57.7 69.7 59.5 68.7 63.9 Ketebalan kurang sesuai dan amat mudah pecah
D 13 70.1 62.5 59.2 65.1 64.2 Ketebalan kurang sesuai dan mudah pecah
E 16 74.2 58.2 55.0 72.6 65.0 Ketebalan kurang sesuai dan tidak mudah pecah
Jadual 1.0 Jadual purata kekerasan bahan seramik daripada serbuk cangkerang telur ayam yang terhasil.
Jadual 1.0 Graf jisim serbuk cangkerang telur ayam melawan kekerasan bahan seramik daripada serbuk
cangkerang telur ayam yang terhasil.
KESIMPULAN
1.Serbuk cangkerang telur ayam boleh dikitar semula menjadi bahan seramik.
2. Jisim serbuk CaCO3 cangkerang telur ayam berkadaran terus dengan nilai kekerasan
seramik yang terhasil.
3. Jisim serbuk cangkerang telur ayam yang paling sesuai ialah 16g kerana ketebalan
yang sesuai untuk menghasilkan pelbagai produk dan mempunyai nilai kekerasan
yang tinggi. Hipotesis diterima.
BAB 5
HASIL DAN PERBINCANGAN
BAB 5 HASIL DAN PERBINCANGAN
5.0 Analisis Keputusan
1. Kecerunan graf mewakili kadar kekerasan yang diperolehi. Hubungan yang diperoleh
ialah semakin besar jisim serbuk cangkerang telur ayam, semakin tinggi nilai kekerasan yang
diperoleh.
2. Cangkerang telur ayam yang sudah diasingkan membrannya dan telah dihancurkan
sehingga halus dimampatkan untuk merapatkan jarak antara zarah-zarah cangkerang telur
tersebut. Prosedur ini juga penting untuk mengelakkan serbuk cangkerang telur tersebut
mempunyai liang-liang udara yang akan menyebabkan zarah-zarah udara akan bercampur
dengan zarah-zarah cangkerang telur dan hal ini akan menyukarkan proses pengujian
kekerasan cangkerang telur itu.
3. Setelah cangkerang telur itu dimampatkan dengan nilai tekanan yang telah ditentukan,
kepingan tersebut mestilah dipanaskan dengan suhu yang tinggi untuk menyingkirkan
molekul-molekul air yang terkandung dalam kepingan cangkerang telur tersebut. Proses ini
mirip dengan proses penyejatan dan proses ini mengambil masa yang agak lama untuk
mengeringkan kepingan tersebut.
4. Permasalahan yang dihadapi sepanjang menjalankan proses penghasilan seramik
daripada serbuk cangkerang telur adalah seperti berikut:
a) Terpaksa menggunakan tenaga yang sepenuhnya untuk menggiling
cangkerang telur bagi menghasilkan serbuk cangkerang telur yang lebih
halus kerana tiada mesin penggiling yang khusus untuk tujuan industri.
b) Membuat proses dan teori pengasingan membran telur daripada
cangkerang telur ayam dengan kadar yang maksimum. Proses
pengasingan yang dimaksudkan ialah proses yang praktikal dalam bidang
perindustrian.
c) Mendapatkan bahan campuran atau bahan kimia yang dapat
meningkatkan nilai kekerasan dan mengukuhkan struktur seramik
daripada serbuk cangkerang telur ayam mengikut teori pengaloian.
BAB 6
KESIMPULAN
BAB 6 KESIMPULAN
6.0 Rumusan
Cangkerang telur ayam berpotensi untuk dikitar semula menjadi bahan seramik. Struktur
kalsium karbonat, (CaCO3) yang dipisahkan dan digiling halus akan dimampatkan di bawah
tekanan suhu dan tempoh dan membentuk pepejal seramik yang praktikal dalam kehidupan.
Nilai kekerasan yang ditentukan sesuai untuk penggunaan seramik dalam penghasilan
pinggan mangkuk, jubin lantai dan juga dalam penghasilan kraftangan.
6.1 Pencapaian objektif kajian
1. Kos pelupusan sampah dapat dikurangkan.
2. Gangguan ekosistem di lokasi sumber batu kapur dikurangkan.
3. Kos produk seramik lebih murah.
6.2 Kajian masa hadapan
1. Mencari bahan kimia tambahan untuk menambah kekerasan dan ketahanan seramik
daripada cangkerang telur ayam dengan menggunakan teori pengaloian agar seramik yang
dihasilkan lebih kuat dan tegar daripada sebarang gangguan .
2. Mencari alternatif untuk menghaluskan dan memisahkan lapisan Kalsium karbonat
(CaCO3) yang sesuai digunakan dalam industri secara kormesil.
3. Mempelbagaikan seramik daripada sumber ini dengan mencari pigmen warna yang dapat
mencorakkan dan lebih mengkomersialkan bahan seramik ini.
RUJUKAN
1.R. B. Von Dreele,” combined rietveld and stereo chemical Restraint Refinement of a
crystal Stucture ,” Jounal of Applied Crystallography 32.1084-1089(1999)
2.Y.Nys, J.gautron ,M.D.McKee, J.M. Garcia-Ruiz, M.T.Hincke,Biochemical of a
functional characterisasion of egg shell natrix proteine in hens.World is Poutry
Science Journal 57(2001)401-413
3.R>M>G> Hamilton,The Microstructure of the Hen is Egg Shell – A short review ,
Food Microstucture 5 (1986),99-110.
4.P.Hunton ,Understanding the architecture of the egg shell, World is Poultry Journal
51 (1995) 141-147.Materials Stucture,vol.10,number 1(2003)39
5.http://lansce .lanl.gov/re search/vondreele.html.
6.Chicken Egg shell Microstucture Studied by Powder Diffaction.htm
LAMPIRAN I
APPLICATION OF POWDER DIFFRACTION IN BIOLOGY?
THE EGG-SHELL MICROSTRUCTURE
L. Dobiášová, R. Kužel , H. Šíchová
Faculty of Mathematics and Physics, Charles University, Ke Karlovu 5, 121 16 Praha 2
In last years, renaissance of rather old and traditional technique - X-ray powder diffraction
can be observed. This was initiated by both the interest in design of new materials (in
materials science, physics and chemistry, where it plays the role of a basic method), and also
by fast development in instrumental techniques – X-ray optics and detection which enhanced
its possibilities.
Powder diffraction pattern contains different kind of information . Peak positions and
intensities are related to crystal (atomic) structure, i.e. the type and size of lattice cell and
atomic positions and consequently it can be used for structure refinement and even structure
determination in some cases. As a finger print of each individual phase, the diffraction pattern
can be an ideal tool for phase analysis.
However, there is much more hidden in the pattern. Variations of lattice parameters and
intensitites can detect lattice defects. This is related to the so-called real structure of material,
the term which is also used for structural features in the scale of nanometers, i.e. grains or
subgrains. The topics which is now of great interest because of intense research of
nanomaterials. Powder diffraction analysis nowadays may include application of different
diffraction geometries and analysis of peak positions, intensities and widths. This makes
possible a complete PXRD analysis – phase analysis, structure refinement, stress, strain,
crystallite size and texture analysis.
Can the technique be of any use for biologists? There have not been many applications yet.
Main interest of biologists now seems to be directed to protein crystallography where even
synchrotron single crystal diffraction may be insufficient. However, recently, an attempt to
use powder diffraction for structure refinement of proteins has appeared [1, 2] too.
In present work, we have tried to perform more complete diffraction analysis of different
egg-shells.
The biological function of the egg-shell is a chamber for embryonic development and from
which the chick is able to emerge at the appropriate time. The requirements of the table egg
industry are different. The industry sustains economic loss from cracked eggs and some of
the cracking can be attributed to the deficiencies in the egg-shell structure. This is one of the
reasons why the attention to eggshell is devoted [3-5].
The egg-shell consists of several mutually through-growing layers of CaCO3. The innermost
layer – mamilary layer ( 100 μm) grows on the outer egg membrane and creates the base on
which the palisade layer constitutes the thickest part ( 200 μm) of the egg-shell. The top
layer is the vertical layer ( 5-8 μm) covered by the organic cuticle.
Different kinds of hen´s and bird´s egg-shells in the powder form or as a whole from both
sides of the shell were examined by powder diffractometry and film back-reflection method.
The powder patterns were evaluated by the fitting of diffraction profiles with the Pearson VII
function. The lattice parameters, peak intensities and profile broadening were analysed. At
the Bragg-Brentano setting (2Θ= 40o) the Cu radiation penetrates approximately into the 9
μm of the egg-shell, so the measurements from the inner and outer shell surface can give
evidence of the mamilary and palisade layer, respectively.
The results obtained on egg-shells of very different origins shown no significant differences
in lattice parameters that correspond well to the PDF-2 values. The patterns contained only
basic phase CaCO3 (space group no. 167: R-3c) with a small addition of magnesium (0.3 wt.
% , determined by atomic absorption). Diffraction patterns of powders obtained from all the
eggs investigated correspond very well to the pattern of standard CaCO3. The correspondence
is very good including intensities. The patterns obtained from egg-shell powders are also very
similar to the standard pattern, regardless larger line broadening.
However, there are differences between powders and both sides of the shells. For inner shell
surfaces, the intensities are only slightly different than in powders (including standard one)
but there is significant line broadening indicating fluctuations of lattice spacings (the mean
local strain of about 0.2 %). On the other hand, for outer shell surfaces, there is much smaller
broadening of lines, similar to powders, but significant changes of intensities indicating the
00l textures of grains. This is also an evidence of presence of two basic layers, structurally
very different – mamilary and palisade. The meaning of crystallographic texture has been
emphasized [3, 4]. It was steted that the breaking strength of the eggshell is inversely related
to the degree of calcite orientation and conversely, reduced strength in the eggshell from aged
hens coincides with a high variability of texture [3].
As a general conclusion and amazing fact, we can say that any differences of XRD
parameters between the eggs of very different origin are not significant. So that their
microstructure and composition, as they can be seen by XRD, are the same.
This work was an attempt for non-traditional application of powder diffraction and it was
shown that it may be helpful for biologists not only for phase analysis but also for the study
of nanostructure of inorganic crystalline phases in biological objects which is closely related
to the overall microstructure which is strongly influenced by proteins taking part in the egg
creation. The eggshell matrix proteins influences the process of crystal growth by controlling
size, shape and orientation of calcite crystals. The formation of avian eggs belongs to most
rapid mineralization processes known.
The work has been initiated and supported only by private interests of the authors.
1. R. B. Von Dreele, “Combined Rietveld and Stereochemical Restraint Refinement of a Protein Crystal
Structure,” Journal of Applied Crystallography 32, 1084-1089 (1999).
2. http://lansce.lanl.gov/research/vondreele.html
3. Y. Nys, J. Gautron, M. D. McKee, J. M. Garcia-Ruiz, M. T. Hincke, Biochemical and functional
characterisation of eggshell matrix proteins in hens.World’s Poultry Science Journal, 57 (2001), 401-413.
4. R.M.G. Hamilton, The Microstructure of the Hen’s Egg Shell – A short review., Food Microstructure,
vol 5 (1986), 99-110.
5. P. Hunton, Understanding the architecture of the egg shell, World’s Poultry Science Journal, vol. 51
(1995), 141-147.
CONCEPTS OF EGGSHELL QUALITY
By Dr. Gary D. Butcher and Dr. Richard D. Miles*
Much information has been learned about eggshell quality during the past fifty years. During
this period of time, the genetics of the chicken, diets, house design and management practices
have changed dramatically. In the future, it is very likely that additional changes will have to
he made by the commercial egg industry. No matter what changes occur, the eggshell needs
to be as strong as possible to maximize the number of eggs reaching the market.
Many factors influence eggshell breakage. Eggshell breakage is directly related to the quality
of the shell. It is impossible, even with current knowledge, to correct all eggshell quality
problems. We can, however, make significant reductions in the number of eggs lost due to
poor shell quality. This can be accomplished if one realizes that no single factor is usually
responsible for egg breakage. Many factors are known to be related to eggshell quality. These
include adequacy of nutrition, flock health problems, management practices, environmental
conditions, and breeding. The following are some of the major factors associated with
eggshell quality. A brief account of each factor is provided.
THE EGGSHELL ITSELF
Most good quality eggshells from commercial layers contain approximately 2.2 grams of
calcium in the form of calcium carbonate. About 95% of the dry eggshell is calcium
carbonate weighing 5.5 grams. The average eggshell contains about 0.3% phosphorous, 0.3%
magnesium, and traces of sodium, potassium, zinc, manganese, iron and copper. If the
calcium from the shell is removed, the organic matrix material is left behind. This organic
material has calcium binding properties, and its organization during shell formation
influences the strength of the shell. The organic material must be deposited so that the size
and organization of the crystalline components (mostly calcium carbonate) are ideal, thus
leading to a strong shell. The majority of the true shell is composed of long columns of
calcium carbonate. There are other zones that are involved in the self-organization giving the
eggshell its strength properties. Thus, shell thickness is the main factor, but not the only
factor, that determines strength. At present, dietary manipulation is the primary means of
trying to correct eggshell quality problems. However, the shell to organic membrane
relationship is also critical to good shell quality and must be considered.
An eggshell that is smooth is desirable, as rough-shelled eggs fracture more easily. Large
eggs will usually break more easily than small ones. The main reason for this is that the hen
is genetically capable of placing only a finite amount of calcium in the shell. As the hen ages
and the eggs get bigger, a similar amount of calcium has to be spread over a larger surface.
Therefore, controlling the rate of egg weight change can influence eggshell quality as the hen
ages. Controlling feed intake by changing the temperature inside the layer house influences
egg size. It must be remembered that many factors can influence the amount of calcium being
laid down by the hen. Just because an eggshell is thick does not necessarily mean that it is
strong. Sometimes a thinner eggshell is stronger than a thicker eggshell. The reason for this is
due to the shape and organization of the organic and inorganic components of the shell.
FEEDING
The importance of adequate nutrition in providing the hen what she needs to maintain
adequate eggshell quality is obvious. A hen lays approximately 250 eggs per year which
correspond to 20 times the quantity of calcium in her bones at any one time. Therefore, the
calcium requirement of the laying hen is great. It can be calculated that during the 20 hours
that are required to form an eggshell, 25 milligrams of calcium must be deposited on the egg
every 15 minutes. This amount of calcium is the total amount of calcium in a normal hen's
circulatory system at any given time. In addition, the laying hen is not 100 percent efficient in
extracting calcium from the available sources in the diet. Therefore, many times the diet has
to furnish in excess of 4 grams of calcium to the hen daily. Calcium availability values are
sometimes not known, and it must be remembered that higher daily intakes are needed when
the availability values are known to be low.
A high phosphorus content in the feed and excess chlorine may have a negative effect on
eggshell quality. It is possible that these two elements act negatively on eggshell quality
through their influence on the acid-base balance (pH) in the blood. The importance of
adequate vitamin D intake by the hen is obvious, and it is essential for proper calcium and
phosphorus utilization. However, excess vitamin D and its metabolites have not been shown
to benefit eggshell quality when normal hens are already consuming adequate vitamin D.
Other vitamins and trace minerals, when fed in excess of the hen's requirements, have failed
to improve eggshell quality.
ENVIRONMENT
Usually, eggshell quality is not as much of a problem in cooler environments as it is in hot
environments. One of the contributing factors causing poorer eggshell quality in hot weather
is hens not consuming adequate feed. This can lead to problems in body weight, egg
production, egg size, and eggshell quality if measures are not taken to assure adequate daily
nutrient and energy consumption. When environmental temperature becomes excessively hot,
feed intake decreases, and energy becomes the first limiting factor to the hen. Inadequate
consumption of amino acids, calcium, phosphorus, and other nutrients can usually be
corrected by adjusting the nutrient density of the diet. However, it must not be forgotten that
in hot weather, unlike cooler weather, the laying hen has to make critical life sustaining
physiological adjustments in order to cope with the increased environmental temperature.
The laying hen, through panting, resists the rise in body temperature during periods of heat
stress. At the same time, the acid-base balance in the bird's blood is changed. We sometimes
forget that the laying hen has to cool her body in extremely hot environments and this will
shift her physiological priorities from producing eggs and maintaining an adequately calcified
eggshell to that of staying alive. In such situations, maximum egg mass (egg production times
egg weight) along with maximum eggshell quality are difficult to achieve with any age bird.
DISEASE AND EGGSHELL QUALITY
Not all diseases affecting chickens cause a decline in eggshell quality. However, egg
production will usually decline. An example of a disease that can affect the numbers of eggs
and not necessarily the quality is infectious laryngotracheitis. Other common viral diseases,
such as egg drop syndrome (EDS), avian influenza (AI), Newcastle disease (ND) and
infectious bronchitis (IB), may produce severe effects on eggshell and internal quality. Many
times the total number of eggs is not influenced, even though the egg records indicate a drop
in total collectable eggs. This is due to the increase in non-collectable eggs (shell-less or
ultra-thin shells) that are lost under the cages. This is a common occurrence with EDS. It has
been established that the EDS virus affects only the shell gland, but with ND and IB every
portion of the reproductive tract can be affected.
If one disease had to be singled out as being responsible for the majority of the economically
significant production losses in egg layers, it would have to be infectious bronchitis.
Infectious bronchitis virus, a coronavirus, has a preference for the mucus membranes of the
respiratory and reproductive tracts. The kidney is also affected by certain IB virus strains. Not
only is eggshell quality affected, but internal quality also declines. Watery whites are very
common and can persist for long periods after egg production returns. Also, an IB outbreak
can result in a pale-colored shell in brown shell eggs.
*DVM, Ph.D., poultry veterinarian, and Ph.D., poultry nutritionist, Poultry Science
Department, respectively, University of Florida, Gainesville.
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Copyright 1995-2004 by Dennis Hawkins, All Rights Reserved.
The Egg-Shell Microstructure Studied by Powder
Diffraction
L. Dobiášová†1, R. Kužel1, H. Šíchová1, J. Kopeček2
1Faculty of Mathematics and Physics, Charles University, Ke Karlovu 5, 121 16 Praha 22Institute of Physics, Academy of Sciences of the Czech Republic † in memoriam
In last years, traditional technique of powder diffraction known mainly to materials scientists,
physicists, chemists, mineralogists is also applied to biological materials. First powder
diffraction studies of protein structures has appeared [1, 2]. However, powder diffraction is
known also as a suitable tools for studies of the so-called real structure of materials. In
present work, we have tried to perform more complete diffraction analysis of different egg-
shells.
The biological function of the egg-shell is a chamber for embryonic development and from
which the chick is able to emerge at the appropriate time. The requirements of the table egg
industry are different. The industry sustains economic loss from cracked eggs and some of
the cracking can be attributed to the deficiencies in the egg-shell structure. This is one of the
reasons why the attention to egg-shell is devoted [3-5].
The egg-shell consists of several mutually through-growing layers of CaCO3. The inner most
layer – mamilary layer ( ~100 µm) grows on the outer egg membrane and creates the base on
which the palisade layer constitutes the thickest part 5-8 µm)200 µm) of the egg-shell. The
top layer is the vertical layer (( covered by the organic cuticle. Different kinds of hen´s and
bird´s egg-shells in the powder form or as a whole from both sides of the shell were
examined by powder diffractometry and film back-reflection method. The powder patterns
were evaluated by the fitting of diffraction profiles with the Pearson VII function.
The lattice parameters, peak intensities and profile broadening were analysed. At ) the Cu
radiation penetrates approximately= 40the Bragg-Brentano set ting (2 into the 9 µm of the
egg-shell, so the measurements from the inner and outer shell surface can give evidence of
the mamilary and palisade layer, respectively. The results obtained on egg-shells of very
different origins shown no significant differences in lattice parameters that correspond well to
the PDF-2 values. The patterns contained only basic phase CaCO3 (space group no. 167: R-
3c) with a small addition of magnesium (0.3 wt. % , determined by atomic absorption).
Diffraction patterns of powders obtained from all the eggs investigated correspond very well
to the pattern of standard CaCO3. The correspondence is very good including intensities. The
patterns obtained from egg-shell powders are also very similar to the standard pattern,
regardless larger line broadening.
However, there are differences between powders and both sides of the shells. For inner shell
surfaces, the intensities are only slightly different than in powders (including standard one)
but there is significant line broadening indicating fluctuations of lattice spacings (the mean
local strain of about 0.2 %). On the other hand, for outer shell surfaces, there is much smaller
broadening of lines, similar to powders, but significant changes of intensities indicating the
(00l) textures of grains. This is also an evidence of presence of two basic layers, structurally
very different – mamilary and palisade. The meaning of crystallographic texture has been
emphasized [3, 4]. It was stated that the breaking strength of the egg shell is inversely related
to the degree of calcite orientation and conversely, reduced strength in the egg shell from
aged hens coincides with a high variability of texture [3].
As a general conclusion and amazing fact, we can say that any differences of XRD
parameters (for inorganic – calcite part) between the eggs of very different origin are not
significant. So that their microstructure and composition, as they can be seen by XRD, are the
same. All the shells investigated exhibited strong texture from outside and no texture from
inside (Fig. 1). This agrees with the SEM pictures (Fig. 2) and known fact that from smaller
more or less isotropical grains larger columnar grains are developed to the outer side. This
work was an attempt for non-traditional application of powder diffraction with the aim to
show that the method may be helpful also for biologists. Not only because of the phase
analysis but also for the study of nanostructure of inorganic crystalline phases in biological
objects. This is closely related to the overall microstructure strongly influenced by proteins
taking part in its creation. The egg-shell matrix proteins influences the process of crystal
growth by controlling size, shape and orientation of calcite crystals. The formation of avian
eggs belongs to most rapid mineralization processes known.
1. R. B. Von Dreele, "Combined Rietveld and Stereochemical Restraint Refinement of a
Protein Crystal Structure," Journal of Applied Crystallography 32, 1084-1089 (1999).
2. http://lansce.lanl.gov/re search/vondreele.html.
3. Y. Nys, J. Gautron, M. D. McKee, J. M. Garcia-Ruiz, M. T. Hincke, Biochemical and
functional characterisation of egg shell matrix proteins in hens. World's Poultry Science
Journal 57 (2001) 401-413.
4. R.M.G. Hamilton, The Microstructure of the Hen's Egg Shell - A short review, Food
Microstructure 5 (1986), 99-110.
5. P. Hunton, Understanding the architecture of the egg shell, World's Poultry Science
Journal 51 (1995) 141-147. Materials Structure, vol. 10, number 1 (2003) 39.
ADAS
IN CONFIDENCE
UTILISATION OF
EGG SHELL WASTE
FROM UK EGG PROCESSING
AND
HATCHERY ESTABLISHMENTS
Prepared for Prepared by
Mr David Jones Jason Gittins, Senior Consultant
Pigs, Eggs and Poultry Division Assisted by Catherine Drakley, Research Consultant
DEFRA ADAS Consulting Ltd
Whitehall Place East Woodthorne
London Wergs Road
SW1A 2HH Wolverhampton
WV6 8TQ
May 2002 Tel: 01902 693197
CONTENTS
1 INTRODUCTION *
2 SOURCES AND COMPOSITION OF WASTE *
2.1 Egg Processing Premises *
2.1.1 Production of pasteurised liquid egg *
2.1.2 Production of boiled egg (minus shell) for sandwich fillings etc. *
2.2 Hatcheries *
3 CURRENT DISPOSAL OR RECOVERY OPTIONS *
3.1 Incineration *
3.2 Landfill *
3.3 Land-spreading *
4 LONGER TERM SOLUTIONS *
4.1 Effectively Separating the Shell and Membrane *
4.1.1 Uses of egg shell membrane *
4.1.2 Uses of purified shell *
4.2 Feed Options *
4.2.1 Feeding ground egg shell waste *
4.2.2 The nutritional value of day old chick meal *
4.2.3 Lactic acid fermentation of hatchery waste *
4.3 Other Possibilities for Utilising Egg Shell and Hatchery Waste *
5 FURTHER RESEARCH *
6 CONCLUSIONS *
References *
1 INTRODUCTION
A recent report prepared by ADAS for DEFRA – MPEP Branch (The UK Egg Products
Industry, May 2001) highlighted the difficulties which the disposal of egg shells presents to
UK egg processors. In the report, it was estimated that some 10-11,000 tonnes of egg shell
has to be disposed of each year by egg processors and producers of hard cooked eggs. The
vast majority of this is produced by comparatively few businesses. Similar issues affect UK
hatcheries for both egg and poultry meat production where again the quantity of egg shell and
other hatchery waste to be disposed of is considerable. It is estimated that this amounts to
some 360 tonnes per annum for egg laying birds and 4,800 tonnes per annum for broilers. An
estimated 30 million male laying strain chicks also need to be disposed of.
The disposal of egg shells and hatchery waste is not only a problem for the UK industry.
However, the problem is alleviated in many other countries since it is acceptable practice to
feed treated egg shell back to animals as a source of calcium. Since many of the egg
processing plants in other parts of Europe are part of co-operative groups which incorporate
animal feedmills, this is a very efficient option. Research has been ongoing for some years on
alternative uses for the waste in the UK, other EU countries and worldwide.
UK consumption of eggs in further processed form is growing. Approximately 20% of UK
egg production enters the further processed chain compared to 14% in 1994. It is likely that
the consumption of further processed eggs will continue to increase as ready prepared meals,
cakes and eating out become ever more popular, and therefore the problem of waste disposal
will continue to increase. By 2010, it is predicted that products could account for 30% of the
UK egg market.
The egg processing industry in particular is very competitive, with low margins being the
norm due to global competition and cheap imports. The costs associated with egg shell
disposal (much of which is currently taken to landfill sites) are significant, and set to continue
increasing as landfill taxes increase. Alternative solutions, which transform the waste product
into a saleable item would be welcomed, but investment to date is limited into new areas of
waste processing. However, new technologies are being investigated, which although
seemingly priced out of the market at present, may become economically viable in the not too
distant future.
The objective of this report is to identify the options for and costs of disposal that are
currently available to the egg processors and hatchery industries. The current disposal options
will be considered in terms of current and future costs.
The future potential uses of egg shell and hatchery waste from the poultry industry will be
established by a review of the literature, and the practical issues likely to be associated with
these will be evaluated. Any further research or development requirements will be
highlighted.
The UK egg products industry is particularly concerned about its ability to remain
competitive in future. Finding solutions to the problem of egg shell waste would be a step
towards safeguarding the competitive position of the UK industry.
2 SOURCES AND COMPOSITION OF WASTE
2.1 Egg Processing Premises
2.1.1 Production of pasteurised liquid egg
Shell from pasteurised liquid egg is perhaps the most difficult waste to manage. The liquid
constituents are rapidly degraded microbiologically causing unpleasant sulphurous odours.
There is a need to remove this material for disposal or recovery on a very regular basis. This
leads to frequent collections by waste management companies in relatively small
consignments.
2.1.2 Production of boiled egg (minus shell) for sandwich fillings etc.
The situation is similar to that of pasteurised liquid egg, although the cooking process will
slow down the rate of microbiological degradation slightly.
Egg shell waste primarily contains calcium, magnesium carbonate (lime) and protein.
2.2 Hatcheries
Waste from hatcheries will contain tissue from the developing embryo in the egg and the
cause of the non-viable development will generally be unknown. As the cause of this may
have been due to pathogens which can also affect humans, the subsequent waste will be
subject to the Animal By-products Order 1999 (Statutory Instrument 1999 No. 646) and
subsequent amendments. The waste must, therefore, be consigned for rendering at a cost of
£50-85/tonne.
3 CURRENT DISPOSAL OR RECOVERY OPTIONS
3.1 Incineration
Incineration with waste-to-energy (combined heat and power) is considered to be a desirable
but high cost waste disposal option. Costs can exceed £35/tonne and incinerator capacity is
limited. In order to maximise the recycling opportunities for egg shells, the material should
be incinerated independently of other wastes. The calcium/magnesium content of the shells
will be converted into calcium/magnesium oxide and the resultant burnt lime could be used as
a liming agent. In addition, most of the constituents are not organic and of low calorific
value, making the material less attractive as an energy source.
This option is, therefore, not considered to be viable at this time.
3.2 Landfill
Environmental concerns over the production of methane, carbon dioxide and other volatile
organic chemicals and the threat to controlled waters from leachate production, has led to
tighter controls over the management of landfill sites. Current and forthcoming EU and UK
regulations also demand high standards of site monitoring and engineering by site operators.
The result of these changes and the threat of the impending introduction of restrictions on the
amount of putrescible material (organic carbon) which may be landfilled means that material
such as egg shells will be less attractive for landfill disposal.
Landfill Tax is currently at £13/tonne for egg shell waste and is set to rise by £1/tonne for the
next few years.
The cost of landfill will vary according to the proximity and availability of sites but will vary
between £15/tonne and £35/tonne, excluding Landfill Tax and haulage.
In real terms, this equates to a cost of 2.8 – 4.8 pence per 10kg of pasteurised egg produced
for disposing of the shell waste (not including haulage).
In the future it is likely that restrictions on the amount of carbon allowed to be deposited into
landfills will require some form of pre-treatment such as composting, aerobic/anaerobic
digestion or chemical treatment.
Disposal to landfill is currently the most common method of disposal of eggshell waste, as it
is the cheapest. However due to the increasing levels of landfill tax, and likely future
restrictions on carbon depositing it is likely to become less attractive in the future.
3.3 Land-spreading
Land-spreading of industrial wastes is carried out under the exemptions from licensing in
paragraph 7 of Schedule 3 of the Regulations (The Waste Management Licensing
Regulations 1994, Statutory Instrument 1994 No. 1056) to permit the beneficial recovery of
specified wastes. Controlled wastes listed in Table 2 of paragraph 7 of Schedule 3 of the
Regulations that can be applied to land subject to the conditions of this provision are as
follows:
Part I
Waste soil or compost
Waste wood, bark or other plant matter
Part II
Waste food, drink or materials used in or resulting from the preparation of food or
drink
Blood and gut contents from abattoirs
Waste lime
Lime sludge from cement manufacture or gas processing
Waste gypsum
Paper waste sludge, waste paper and de-inked paper pulp
Dredgings from any inland waters
Textile waste
Septic tank sludge
Sludge from biological treatment plants
Waste hair and effluent treatment sludge from a tannery
Egg shell waste falls within the category of waste food, drink or materials used in or resulting
from the preparation of food or drink and could, subject to adequate scrutiny, be suitable for
land spreading. The total neutralising value (lime) is almost the same as ground chalk or
limestone tonne for tonne.
However, the physical nature of the egg shell waste (large shell fragments) and the foul rotten
egg odours produced when the material degrades, reduce the liming value and render the
waste difficult to recycle to land. Ideally, the waste should be dried at source, transported to a
site where it can be finely ground and used as a source of lime in agriculture. Some form of
intensive heat treatment will be necessary at some point in the process to guarantee pathogen
kill. However the costs of drying, additional transport, grinding and heat treatment required
are likely to make this option less desirable in the short term.
4 LONGER TERM SOLUTIONS
This section of the report considers the past and ongoing research work on the problem of the
utilisation of egg shell and hatchery waste. These techniques are not considered economically
viable at the present time, but a basic understanding of the scope of potential solutions is
useful in looking toward a future when land-filling may not be an option as a disposal
method.
4.1 Effectively Separating the Shell and Membrane
A major problem with profitable utilisation of eggshell waste is ensuring the complete
separation of the shell and the membrane. Many methods have been tried to completely
separate the membrane from the shell, as when separated, both items can have significant
value. Shells have been dried, crushed, acid treated, abraded and tumbled but the membrane
has remained attached to the shell. In 1997 an American company used a machine normally
used for meat processing (a comitrol) that finely cut the eggshells to a powder. When the
resultant powder was mixed with water, the shell fragments sank and the membrane particles
were suspended in the water. This process has been patented (WO 98/41326,
PCT/US98/05315). The membrane and the shell can then be used for several purposes.
4.1.1 Uses of egg shell membrane
Egg shell membrane contains around 10 % collagen, including the most common Type 1
collagen and the unusual Type 10 collagen. The potential value of collagen from egg shell
membrane is huge, especially in the medical area, where purified collagen can sell for up to
US$1000 per gram. Collagen is used for skin grafts, dental implants, angioplasty sleeves,
cornea repair, plastic surgery, treatment of osteoporosis and pharmaceuticals as well as food
casings and film emulsions.
This is however a very specialised product, and a thorough investigation of the potential size
of the market would need to be carried out before any investment occurred. It is unlikely to
be a route that an egg processor would go down directly, although a co-operative of
processing companies might be able to act as suppliers of material for other specialist
companies.
4.1.2 Uses of purified shell
The membrane free shell powder can be used in the paper industry, or in agriculture as a lime
substitute or calcium supplement
4.2 Feed Options
Egg shell waste does have a theoretical value either as an animal feed or as a fertiliser or lime
substitute. In many other countries, it is accepted practice for egg shells to be dried and used
as a source of calcium in animal feeds. This is currently not undertaken in the UK, although it
would be a very efficient use of the industry’s by-products. It is not used due to concerns over
the transfer of pathogens from raw animal by-products.
4.2.1 Feeding ground egg shell waste
The following provides an example of what could be done, based on studies by Froning and
Bergquist (1990). Egg shell waste was ground (70%) and blended with technical albumin
(8%), maize (5%), soya-bean meal (17%) and propionic acid (0.15%). The blend was
extruded, cooled and fed to laying hens as a protein and calcium supplement in a fully
formulated diet. The process of extrusion produced a microbiologically safe product. Hens
fed the extrudate were not adversely affected in comparison to control birds (rate of lay, feed
conversion, mortality, shell thickness and shell strength). This technique is more practical
than drying and storing waste shells, as the fresh shells are used on a daily basis. The
recycling of the nutrients back to the hen could also be seen as being environmentally logical.
However, there is the risk of bacterial contamination being circulated back to the flock, and
consumer perception of hens being fed a recycled product.
It is unlikely that egg shell waste will be acceptable to the UK consumer for recycling into
processes linked to the food chain. This includes the recycling of waste to agricultural land,
in the absence of an agreed form of auditable enhanced treatment. As a result, most wastes of
this type are consigned to landfill, although we do know of some operators who have
recycled egg shell waste to agricultural land in the past. Shells from cooked eggs may
however be accepted for this purpose having undergone an intensive heat treatment.
4.2.2 The nutritional value of day old chick meal
It is estimated that within the UK approximately 30 million male chicks from laying hen
strains are culled each year. A limited number of these are utilised as a low-priced animal
feed-stuff (at zoos and wildlife parks) but the remainder usually go to landfill. Research by
Tacon (1982) quantified the nutritive value of processed chick meal. The chick meal was
equivalent to meat meal, and is a good source of methionine, lysine and cystine. The chick
meal was a well balanced source of most minerals, although the level of zinc was extremely
high. Animals have a high tolerance for zinc, but very high levels may depress food intake or
induce copper deficiency.
There is a serious risk of potential health hazards arising from pathogenic microbial
contamination or parasites within the waste material, therefore it is essential that the products
must be processed to ensure destruction of the disease-causing organisms. This will add to
the cost of the process.
4.2.3 Lactic acid fermentation of hatchery waste
Hatchery waste has not been fully utilised historically as the products are highly perishable
and rapidly spoil unless they are immediately rendered or dehydrated to a stable form. In
practice the cost of regular haulage of small loads to the renderers has also proved
prohibitive. Research has been carried out on the possibility of preserving the hatchery waste
by fermentation in order to produce a nutrient dense feed-stuff that can be fed to poultry
(Deshmukh and Patterson, 1997). Cockerel chicks and shell waste were ground and
fermented in sealed containers with a fermentation culture. The fermented product was
extruded and dried, and included as a feed ingredient in a feed evaluation trial for broiler
chicks. Diets supplemented with hatchery by-products were comparable with control diets in
terms of bird performance (body weight gain and feed conversion). Carcass yields were not
adversely affected. Again, this is unlikely to be a practical proposition in the UK food
industry.
4.3 Other Possibilities for Utilising Egg Shell and Hatchery Waste
Production of biodegradable plastics from eggshell membrane proteins.
Altering of food-borne bacterial pathogen heat resistance with an eggshell membrane
bacteriolytic enzyme.
A human dietary calcium supplement especially for post menopausal women,
eggshells also contain useful amounts of microelements such as strontium (Sr),
fluorine (F) and selenium (Se).
Eggshell membrane can be used as an adsorbent for the removal of reactive dyes from
coloured waste effluents.
Eggshell membrane can be used to eliminate heavy metal ions from a dilute waste
solution
5 FURTHER RESEARCH
ADAS is already carrying out research into the viability of drying, grinding and conditioning
waste into useful by-products. These include safe products for land-spreading and substrates
for a waste-to-energy boiler. Current costs for such a technique could be in the region on £40
– 45 / tonne, but will depend upon the location of the site. This option may be economically
viable as it is similar to the cost of landfill (including tax and haulage charges).
6 CONCLUSIONS
The UK industry has a major problem with the disposal of egg shell and hatchery waste, due
to the substantial, and rising, costs of such disposal. Consumer pressure over food safety
means that recycling of treated waste back to poultry as a nutrient dense food source is
currently not acceptable and unlikely to become so in future.
At present, therefore, it appears that landfill is still the most economic means of disposal of
the large quantities of eggshells currently produced. But due to high disposal costs the UK
industry is in danger of losing out to cheaper imported egg products from countries where
disposal costs are considerably lower. In future, landfill taxes are set to rise and restrictions
on the amount of carbon that can be sent to landfill will tighten.
Some of the longer term solutions set out in this report may therefore become more feasible
but there is a need for more research into affordable and practical disposal options to help the
competitive position of the UK industry in the near future. It is recommended that a pilot
study is set up, using ADAS facilities and co-operation from industry to further evaluate the
utilisation of dried, ground egg shells for land spreading or energy production.
References
DESHMUKH, A.C. and PATTERSON, P.H., (1997). Preservation of hatchery waste by
lactic acid fermentation. 2, large scale fermentation and feeding trial to evaluate feeding
value. Poultry Science, 76, 1220 – 1226.
FRONING G.W., and BERGQUIST, D (1990). Research note: utilisation of inedible
eggshells and technical egg white using extrusion technology. Poultry Science, 69, 2051 –
2053.
TACON, A.G.J., (1982). Utilisation of chick hatchery waste: the nutritional characteristic
Egg and Embryo DevelopmentThe Formation of an Egg:
The Yolk: The chicken egg starts as an egg yolk inside a hen. A yolk (called an oocyte at this point) is produced by the hen's ovary in a process called ovulation.
Cross Section of a Newly Hatched Egg
Fertilization: The yolk is released into the oviduct (a long, spiraling tube in the hen's reproductive system), where it can be fertilized internally (inside the hen) by a sperm. The Egg White (albumin): The yolk continues down the oviduct (whether or not it is fertilized) and is covered with a membrane (called the vitelline membrane), structural fibers, and layers of albumin (the egg white). This part of the oviduct is called the magnus. The Chalazae: As the egg goes down through the oviduct, it is continually rotating within the spiraling tube. This movement twists the structural fibers (called the chalazae), which form rope-like strands that anchor the yolk in the thick egg white. There are two chalazae anchoring each yolk, on opposite ends of the egg. The Eggshell: The eggshell is deposited around the egg in the lower part of the oviduct of the hen, just before it is laid. The shell is made of calcite, a crystalline form of calcium carbonate. This entire trip through the oviduct takes about one day. Growth of the Embryo: The fertilized blastodisc (now called the blastoderm) grows and becomes the embryo. As the embryo grows, its primary food source is the yolk. Waste products (like urea) collect in a sack called the allantois. The exchange of oxygen and carbon dioxide gas occurs through the eggshell; the chorion lines the inside surface of the egg and is connected to the blood vessels of the embryo. The Incubation Period: The embryo develops inside the egg for 21 days (the incubation period), until a chick pecks its way out of its eggshell and is hatched. Definitions:
air cell - an empty space located at the large end of the egg; it is between the inner and outer shell membranes.
chalaza - a spiral, rope-like strand that anchors the yolk in the thick egg white. There are two chalazae anchoring each yolk, one on the top and one on the bottom. (The plural of chalaza is chalazae.)
germinal disc or blastodisc - a small, circular, white spot (2-3 mm across) on the surface of the yolk; it is where the sperm enters the egg. The nucleus of the egg is in the blastodisc.
inner shell membrane - the thin membrane located between the outer shell membrane and the albumin.
outer shell membrane - the thin membrane located just inside the shell.
shell - the hard, protective coating of the egg. It is semi-permeable; it lets gas exchange occur, but keeps other substances from entering the egg. The shell is made of calcium carbonate.
thick albumin - the stringy part of the egg white (albumin) located nearest the yolk.
thin albumin - the watery part of the egg white (albumin) located farthest from the yolk.
vitelline (yolk) membrane - the membrane that surrounds the yolk.
yolk - the yellow, inner part of the egg where the embryo will form. The yolk contains the food that will nourish the embryo as it grows.s of day old chicks and egg shells. Agricultural Wastes, 4, 335 – 343.
LAMPIRAN II
RAJAH 1.0 Struktur asas cangkerang telur ayam.
RAJAH 1.1 Keratan akhbar yang membincangkan kes tarahan gua batu kapur yang semakin menganggu ekosistem di lokasi tersebut.
PROSES I : PROSES PEMBERSIHAN
RAJAH 2.0 Kulit telur ayam yang telah dibersihkan daripada dengan menggunakan air suling untuk menyingkirkan bendasing.
PROSES II : PROSES PENGASINGAN
RAJAH 2.1 Membran telur ayam yang telah diasingkan daripada membrannya dengan menggunakan forsep.
PROSES III : PROSES PENGISARAN
RAJAH 2.2 Cangkerang telur ayam yang telah dikisarkan secara kasar dengan menggunakan mesin pengisar.
PROSES IV : PROSES PENGGILINGAN
RAJAH 2.3 Serbuk kasar cangkerang telur ayam yang telah dikisar digiling halus dengan menggunakan penggiling.
PROSES V : PROSES PEMAMPATAN
RAJAH 2.4.0 Serbuk halus cangkerang telur ayam ditimbang pada jisim tertentu dengan menggunakan mesin elektronik Analytical Balance. RAJAH 2.4.1 Serbuk halus cangkerang telur ayam dimampatkan dibawah tekanan dan tempoh tertentu dengan menggunakan mesin pemampat Pelletizing Press.
RAJAH 2.4.2 Pepejal seramik daripada serbul halus cangkerang telur ayam diletakkan di bawah tekanan suhu dalam mesin ketuhar Purnace EML.
RAJAH 2.5 Seramik yang terhasil daripada pengitaran semula cangkerang telur ayam diuji kekerasannya dengan menggunakan meain penguji kekerasan Hardness Tester.
RAJAH 3.0 Gambar penulis bersama pembantu makmal Fizik di Universiti Teknologi Malaysia Skudai, Johor. Send instant messages to your online friends http://uk.messenger.yahoo.com