Dr. Widodo Hadisaputro, M.Sc

Anatomy of an Egg

1. Eggshell

2. Outer membrane

3. Inner membrane

4. Chalaza

5. Exterior albumen

6. Middle albumen

7. Vitelline membrane

8. Nucleus of pander

9. Germinal disk

10.Yellow yolk

11.White yolk

12.Internal albumen

13.Chalaza

14.Air cell

15.Cuticula 2

ALBUMEN (60 %)

• The egg white is known as the albumen, which comes from albus, the Latin word for “white.”

• contain approximately 40 different proteins:

• OVALBUMIN, CANALBUMIN, OVOTRANSFERIN, LYSOZYM, OVOMUCIN, AVIDIN, ETC 3

Ovalbumin 54%

Conalbumin 13%

Ovomucoid 11%

Lysozyme 3.5%

Globulins (G2, G3) 8.0 %

Ovomucin 1.5%

Other protein components include, flavoprotein (0.8%),

ovoglycoprotein (0.5%), ovomacroglobulin (0.5%),

ovoinhibitor (0.l%) and avidin (0.05%).

MAJOR PROTEINS IN ALBUMEN OF TOTAL PROTEINS (Powrie 1973)

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Egg white contains approximately 40 different

proteins:

YOLK

• Less water, more protein and fat than the white egg

• Contains most of the vitamins and minerals of the egg, including Fe, vitamin A, vitamin D, phosphorus, calcium, thiamine, and riboflavin.

• Source of lecithin (emulsifier).

• Yolk color ranges from just a hint of yellow to a magnificent deep orange, according to the feed and breed of the hen.

• Umur: kuning telur mengabsorbsi air dari albumen: ukuran kuning telur membesar , strukturnya meregang, membran vitelin rusak, bentuk lebih flat.

5

EMULSIFIER CAPACITY

Egg yolk is a source of lecithin, an emulsifier and surfactant.

Lechitin is a substance that helps an emulsion form, or helps keep an emulsion from separating

Aplication :

• Mayonnaise

• butter sauces

• salad dressing

• Stabilizer of bakery products

• Whipped egg

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Lesitin adalah suatu contoh emulsifier yang mampu menstabilkan emulsi air dalam lemak atau lemak dalam air dengan cara menurunkan tegangan antar permukaan antara fase air dan fase lemak

Dengan lesitin dimungkinkan terbentuk suatu dispersi fase lemak yang merata pada suatu fase air

Karakter spesifik dari suatu emulsifier terkait dengan molekul penyusunnya yang mempunyai struktur amphipilik (amphipilic structure)

Suatu molekul emulsifier tersusun atas gugus yang sifatnya lipofilik (mampu mengikat lemak) dan gugus yang sifatnya hidrofilik (mampu mengikat air)

Proses penambahan lesitin biasanya dilakukan di spray tower dengan cara menyemprotkan lesitin kedalamnya. Proses ini umumnya disebut dengan lesitinasi.

Properties Application

Thickening Eggs thicken foods like custards puddings, sauces,

and creamy fillings

Leavening Souffles, sponge & butter cakes, quick breads, and

puffy omelets are leavened by eggs

Coating Meat dishes, breads, and cookies are some foods

with egg components as the base ingredients for

coatings

Binding Eggs bind other ingredients for making meat loaves,

casseroles, and croquettes

Emulsifying Eggs prevent mixture separation in mayonnaise,

salad dressing, and cream puff filling

Clarifying Tiny particles are coagulated in soups and coffee to

create a clear solution

Retarding

Crystallization

Crystallization of sugar is slowed in cake icings and

candies 10

ANTIMICROBIAL AND

ALERGEN ON ALBUMIN

• LYSOZYME

• Immunoglobulin E (IgE)

memicu histamin

• OVOMUCIN (hambat enzim

tripsin)

• AVIDIN: mengkompleks biotin

(Avidin+Biotin komplek):

Biotin tak dpt dicerna 11

14

SHELL (10 %)

• calcium carbonate (CaCO3) 94-97 %, 3-6 % Organic material and Pigment

• Shell strength is depend on the content of CaCO3, Mg, P, dan vit D

• Thickness: 0.2-0.4 mm • Pores: 700 pores/cm2 = 17,000 tiny

pores • Semipermeable membrane: air and

moisture can pass through has a thin outermost coating called the bloom or cuticle that helps keep out bacteria and dust.

• Mucin : covered shell and pores 15

Changes in quality as the egg ages

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Green rots disebabkkan

oleh bakteri Pseudomonas

fluorescen

Black rots disebabkkan

oleh bakteri

Pesudomonas, Proteus

dan Aeromonas sp.

Proteus melanovogenes

penyebab utama warna

gelap pada yolk

Terbentuk gas H2S dan

bau yang tidak enak

Pendinginan (penyimpanan suhu kulkas)

Pemanasan (penggodokan, penggorengan)

Pengeringan (penurunan aktivitas air, tepung telur)

Penggaraman (telur asin)