Index:-
1)Introduction
2)Aim
3)Requirement
4)Procedure
5)Observation
6)Conclusion
7)Result
8)Precaution
9)Bibliography
Introduction:-
Casein is the main protein constituent of milk. It
constitutes about 80% of the total protein in
cow's milk and about 39t of its weight. Itgroup
of protein precipitated when the milk is
slightly acidified. It dissolves slightly In water,
extensively In alkalis' or strong acids. Casein is
a complete protein meaning that it contains all
of the essential amino acids, which the body
can not manufacture on its own. When dried, It
is a white, amorphous powder without taste and
odour. It is a mixed phosphoproteln and occurs
in milk as calcium salt (calcium caseinate) in
the form of micelle. The micelle has a negative
charge. When an acid is added to the milk,
the negative charges are neutralized
Calcium caseinate + acetic acid U casein(s) +
cakium acetate (aq)
The quantity, quaiity and fat-contentfromthe
various milk samples differ with the type of
particular mammals and their fodder. The
composition of milk varies with according to
the animals from which it comes, providing the
correct growth rate and development for the
young of that species. Casein is a slow
digesting protein and it was suspended in the
milk in a complex called micelle. The micelles
aresphericalandare0.04 to0.03Bmindiameter. Milk
composition varleswith the stageof location, age and
breed. Milk is colloidal nature due to the presence of
proteins. Theproteins areheavymolecules; they form
collolds whendispersed In water medium. Theprimary
function of protein in living cellsIstopromotegroMh and
maintenance. Thenltrogen content of milk is distributed
among casein 763t, whenprotein and non-protein
nltrogen Is 636.The structure of proteln consistofa
polypeptide chainofaminoacidsjolnedtogether bypeptide
llink au +. Aroundtheworld,therearemorethansixbillion
consumersofmilk andmilkproduct. Over 750milllon
peopte live in dairyfarminghouseholds.It 1sused In
paints forfastdryingwater-solublemedium (Figure 1).
Casein based glues are formulated from themixture of
casein, water,hydrated lime and sodium hydroxide
•Takeadean dry beaker, put into it 20ccof cow‘s milk and add
30mlof saturatedammonium sulphatesolutionslowly and with
stirring. Fatsbng with casdn willprecipitate out
•Flker the sok‹tIonandtransfer theprecipitates In another beaker.
•Addabout30mlof water tothe precipitate.
•Onlycaseindbsolvesin waterfbrmlng milkysolution leavkig fat
undlssoked.
•Heet themilky salmon to about40•Cand add1%acetk acid
solution drop wise,whencaseingetsprecipitated.
•Flher the PreclPitnte, wash wtth water and let
the prmlPitete dry. Held of caseln
•Weigh the dry solid massIn apreviously welghedwatch
glays.
•s«peatthe experiment withother samplasof milk
Aim:-
To determine the amount of casein present in
different samples of milk.
Milk is a mukinutrient fluid and it is the primary
source of nutrition for human. It consists of 80% of
proteins. The protein in the milk is classified into casein
and whey protein. Milk protein consists of80% of
casein and 2096 whey protein. Thefunction of casein
1sto provide energy to human body. The name of
casein is related to the family of phosphoproteins.
These proteins are commonly found in the
mammalian mllk. This study deals with the
precipMtion of casein from the various milk samples
such as cow milk, goat milk, buffalo milk and also
the samples that availed from the market. The
technique of precipitation of casein is used to
predict the protein content in the milk samples.
Requirement
Apparatus andChemicals
•250mlbeakers
Gunntel
•Chemical balances
•Test tubes
•Filtration flask
•Bunsen burner
•Different samples of milk
•1% acetic acid solution
•Saturated ammonium sulphate solution
Observation Table
Volumeofmilk ‹akenIneachcase 20ml.
No SsznpIos YiefdelraseJ•(gzszzzs)
I Cowmilk 7.8
2 BufFalo milk 4
3 Goai milk ó.4
4 Market milk - A ó.8
S Markct Milk - B 5.S
Theyield of caseinprecipitated fromthe variousmilk samplesof goat
milk, cow
milk and buffalo milk contains 6.4 gm, 7.8 gm and 4 gm
respectively. Similarly, the
milk samplesavailed from the market suchasmllk -Aand milk -B
was6.8gm and
5.5 gm respectively. This shows that the casein precipitated
from the cowmilk containsmore amount of caseln protein than
thegoat and buffalo milk samples. Thelower amount of casein in
the buffalo milk Is may be due to the more fat content in it (8].
The dissimilarkiesbetween the milk samples -Aand Bis
revealed thatthe marketmllk -Bmaybeadultered withwater or any
other substance
Conclusion
This study clearly Indicated that the amount of casein
precipitated from the cow milk washigher than that of
the other milk samples. The quantitative analysis of
casein precipitated from the various milk samples provide
the ample scope to the cottage cheese manufacture.
Accordingto the research findings, cow mllk contains the
largest amount of casein protein. Thus, the cow milk is
suitable for the best muscle growth and basic body building
achievements. It wasfound that goat milk contains the small
amount of casein protein. Although the mineral content of
goat's milk and cow's milk is generally similar, goat's milk
containsmore calcium, potassium, iron, magnesium and
sodlum. All milk haslots of casein butthere are different typesof
casein and for someone who hascasein sensitlvfty, goat
milk may provide an
alternative to which they do not react.
