7/21/2019 Egg Power Point 1
1/34
Eggs
7/21/2019 Egg Power Point 1
2/34
Composition of eggs
% Water Protein Fat CHO
Whole 100 74.6 12.1 11.2 1.2
White 58 88.0 10.1 0.2 0.8
Yolk 31 48.0 16.4 32.9 2.0
7/21/2019 Egg Power Point 1
3/34
Composition of Eggs -
egg white (albumen)
Water (~88%)CHO (~1%)
mainly gluose! may ause brown
"isoloration in "rie" eggs an" har" oo#e"eggs ($aillar" reation)
at (trae)
7/21/2019 Egg Power Point 1
4/34
Composition of Eggs -
egg white (albumen)
&roteins (~11%)! most are glyoproteins'hree primary proteins
ovalbumin(*%)+truture of ,a#e" &ro"uts
ovotransferrin(1%)! ,in"s metal! .isoloration
ovomucoid(11%) &rotease /nhibitor ovomucin(10%)ibrous &rotein!
ontributes to the thi#ness of the white (* 2more abun"ant than in yol#)! ontributes to
the stability of egg white foam
7/21/2019 Egg Power Point 1
5/34
Composition of Eggs -
egg white (albumen)&roteins (ont3n)
globulins (8%) inlu"ing lyso4yme! areimportant for foaming
lyso4yme ability to hy"roly4e apolysahari"e in the ell wall of some
bateria to pre5ent baterial spoilageothers o5oinhibitor! o5ofla5oprotein!o5omiroglobulin! a5i"in (bin"s biotin! but isheat sensiti5e)
7/21/2019 Egg Power Point 1
6/34
Composition of Eggs -
egg yol#&roteins (160*%)
plasma (78%) li5etin 9.9 (protein
ontent ~ 1:%)granular fration phos5itin (16%!arrier of e)! lipo5itellins (7:%) 9.9
(1%)Water (*8%)
7/21/2019 Egg Power Point 1
7/34
Composition of Eggs -
egg yol#9ipi"s (; to ;*%)
triglyerol (66%)
phospholipi" (8%) inlu"ing leithin
(has remar#able emulsifying ability)
holesterol (;%! or : mg)
'he olor of yol# "epen"s on thepresene of arotenoi"s0
2anthophylls not arotene
(9utein an" 4ea2anthin)
7/21/2019 Egg Power Point 1
8/34
7/21/2019 Egg Power Point 1
9/34
Egg uality shell harateristis!shape! soun"ness! leanliness! olor
/nterior >uality si4e of the air ell!firmness of the white! the yol#("istint or flattene" "uring aging)
E5aluate" by an"ling
7/21/2019 Egg Power Point 1
10/34
Egg >uality "uring storage
'he si4e of the air ell inreaseswater e5aporates from the egg through shell
'he egg white beomes thinnero5omuin un"ergoes "egra"ation
pH of white inreases (from ~ 8 to ~?)
"ue to the loss of CO through the pores
7/21/2019 Egg Power Point 1
11/34
Egg >uality "uring storage
'he yol# enlarges an" the membrane wea#ens(water mo5es from white to yol#! 5isosity"ereases! yol# beomes flatter an" sprea"s farther)
.eterioration of o"or fla5or
/nrease" storage temperature aelerates loss of>uality
7/21/2019 Egg Power Point 1
12/34
untionality of Eggs
Coagulation
Emulsifiation
oaming
7/21/2019 Egg Power Point 1
13/34
untionality of EggsCoagulation or @elation
7/21/2019 Egg Power Point 1
14/34
&rotein Coagulation
.enaturation Aela2ation of the tertiarystruture to the seon"ary struture!aompanie" by "ereasing solubility of aprotein
&reipitation of protein as moleulesaggregate (often as a result of energyinput! suh as heating or beating)
&roess that results in a loss of solubilityor a hange from a flui" state to a soli"state0 (@elation is also use" to "esribethe proess0
7/21/2019 Egg Power Point 1
15/34
untionality of Eggs -oagulation
egg white begins to thi#en at~6oC! yol# at ~6oC0 7oC irm
'he gel firmness "epen"s on time temperature of heating @el har"ness "epen"ents on the pH
an" the onentration of protein inrease" pH or protein will inrease
gel har"ness "ilute" protein will inrease oagulation
temperature
7/21/2019 Egg Power Point 1
16/34
untionality of Eggs -oagulation
+ugar "ereases the rate of heat
"enaturation inreases theoagulation temperature
+alts promote oagulation
7/21/2019 Egg Power Point 1
17/34
untionality of Eggs
7/21/2019 Egg Power Point 1
18/34
untionality of Eggs -emulsifiation
ormation of emulsionB mehanial agitation ma#es it
insoluble an" stiff or stableB emulsifying agent (9eithin)
Egg ol# is an oil-in-water
emulsion
7/21/2019 Egg Power Point 1
19/34
untionality of Eggsoaming
7/21/2019 Egg Power Point 1
20/34
untionality of Eggs -foaming
olloi"al suspension bubblessurroun"e" by egg albumen
(protein) globulins ha5e greater foaming
ability
o5omuin stabili4es the foam
7/21/2019 Egg Power Point 1
21/34
untionality of Eggs -fators affeting foaming
$etho"! time an" temperature ofbeating
as beating time inreases! 5olume an"stability of the foam 1st inreases then"ereases
ma2imum stability is reahe" before
ma2imum 5olume room temperature 5s refrigerator
temperature
7/21/2019 Egg Power Point 1
22/34
untionality of Eggs -fators affeting foaming
Charateristis of the egg white thin white 5s thi# white
store" eggs 5s fresh eggs pH
ai"s or ai" salts inreases foam
stability but "elays foam formation
7/21/2019 Egg Power Point 1
23/34
untionality of Eggs -fators affeting foaming
Water water inreases the foam 5olume but
"ereases its stability fat
oil re"ues foam 5olume
so"ium hlori"e re"ues the foam stability! inreases
whipping time
7/21/2019 Egg Power Point 1
24/34
untionality of Eggs -fators affeting foaming
+urose "elays foam formation (so beat then a"")
pro"ues a more stable foam egg yol#
"ereases the foam 5olume
a""iti5es surfatants an" stabili4ers may re"ue
whipping time! inrease foam 5olume
7/21/2019 Egg Power Point 1
25/34
untionality of Eggs
7/21/2019 Egg Power Point 1
26/34
untionality of Eggs -fators affeting foaming
$etho"! time an" temperature ofbeating
harateristis of the egg white pH
water an" fat
so"ium hlori"e surose
egg yol#
a""iti5es
7/21/2019 Egg Power Point 1
27/34
untionality of Eggs
7/21/2019 Egg Power Point 1
28/34
&roesse" Eggs ro4en eggs
egg whites perform well after free4ing thawing
a"" 1:% (wDw) of sugar or salt to yol#sbefore free4ing to ontrol the gelation offro4en yol#
'o pre5ent syneresisF in fro4en oo#e"egg pro"utsB a""ition of gums
B a""ition of itri ai"
B a""ition of salt
7/21/2019 Egg Power Point 1
29/34
&roesse" Eggs Egg substitutes
use of egg white together with a yol#-li#e mi2ture ontaining no holesterol
fortify with fat-soluble nutrients a""ition of arotenoi" for gi5ing the
yol# olor
a""ition of arbo2ymethyl-ellulose(C$C) re"ues weeping aroma an" fla5or are not as goo" as
fresh eggs
7/21/2019 Egg Power Point 1
30/34
&roesse" Eggs .rie" eggs (spray "rying)
pro"uts whole-egg soli"s! yol# soli"s!fortifie" whole-egg soli"s an" whites
growth of miroorganisms is inhibite"
oagulation is not affete"
foaming potential is re"ue"
a"" whipping agents (surfae ati5e)
7/21/2019 Egg Power Point 1
31/34
&roesse" Eggs ll li>ui" eggs shoul" be
pasteuri4e" (61C for ;0 min) to
#ill salmonella an" other potentialpathogens0
=ltrapaseuri4e" li>ui" whole eggs retain funtional properties of fresh
shell eggs
are aseptially pa#age"
7/21/2019 Egg Power Point 1
32/34
untionality of Eggs
+ummaryoloring agent (arotenoi"s in yol#)
emulsifier
mayonnaise! hollan"aise saue! ream puffthi#ening agent (oagulation)
ba#e" (gel) or stirre" (sol) ustar"s!
foamingmeringues! foam a#es (angel! sponge!an" hiffon)
7/21/2019 Egg Power Point 1
33/34
7/21/2019 Egg Power Point 1
34/34
&ro5erbs 11
'he Way of a ool
+eems right to Him,=' a Wise $an
9istens to "5ie