REPORT
OF A PROJECT WORK ON
ISOLATION
OF CAESIN FROM DIFFERENT SAMPLES OF MILK AND ITS CHARACTERIZATION
SUBMITTED
TO
The
Department of Chemistry, Darrang College,
Tezpur-784001,
Assam
For Partial Fulfillment
of HS Final Year Chemistry Practical Examination 2012
SUBMITTED
BY
ANKUR
JYOTI DAS
ROLL……………………
NO…………………………………..
REGISTRATION
NO………………………. OF ……………………………
Session:
2012-13
Under the Guidance of
Dr Palashmoni Saikia
Assistant
Professor, Department of Chemistry
Darrang College,
Tezpur
This
is to certify that this dissertation titled “Isolation of Casein from different
samples of milk and its characterization” submitted by AnkurJyoti Das (HS Final Year) to the
Department of Chemistry, Darrang College,Tezpur, for the partial fulfillment of
the HS Chemistry Prcatical Examination conducted by AHSEC, was carried under my
guidance and supervision during the academic year 2011-12.
I
wish him success in life.
Date: Dr Palashmoni Saikia
Assistant Professor
Department of
Chemistry
Darrang College
Acknowledgement
At
the outset I would like to express my sincere gratitude and thanks to my
chemistry mentor Prof.Tumpa Paulfor
her vital support and guidance in completing this project work.
I
express my special thanks and gratitude to my teacher DrPalashmoniSaikiawho introduced us to the fascinating chemistry of
biomolecules, casein in particular.
I
am grateful toProf.Pronil Kumar Bora,
the HOD, Department of Chemistry for providing us the lab facilities and
chemicals required for carrying out this investigation.
My
sincere thank goes to all my friends and well-wishers without whose inspiration
and support this report would have never been materialized.
Last but not the least I thank my mom for her
encouragement and inspiration without which I would have never been able to
complete this project.
(AnkurJyoti Das) Dated:
“Little
Miss Muffet sat on atuffet, Eating of curds and whey….”
Mother Goose (nursery rhyme)
Milk is the normal product of mammary gland
secretion. It is the most nutritionally complete food found in nature. Rich in
vitamins, carbohydrate, proteins and minerals, milk serves as the best food for
the infants. Animal milks products are the most priced food product. No dish is
complete without butter, cheese or curd. Being a complex biological mixture of
chemicals, isolation and characterization of the components of milk is quite
challenging.
Chemically milk is an oil-in-water emulsionwhere
fatis dispersed as micronsized globules. The fat emulsion is stabilized by
complex phospholipids and proteins that are adsorbed on the surfaces of the
globules.
Among the proteins present in proteins,
casein constitute the major percentage. Casein is a phosphoprotein and exist as
calcium caseinate. Being a phosphoprotein it is amphiphatic and can form
micelle. Micellization of casein makes it soluble in milk. Casein has
an isoelectric point of pH
4.6. Therefore it is soluble as its salt
in milk which has a pH of about 6.6.
If the pH of milk is brought down
below 4.6, casein precipates due protonation of its phosphate head group.
When milk is acidified, it is transformed
into a solidcomponent, called curd, and a liquid component called whey. The
curds contain thebutterfat and casein. The carbohydrate, lactose, is present in
the whey. Curding of milk is due to the bacterial conversion of galactose into
acetic acid.Since the production of the lactic acid also lowers
the pH of the milk, the milk clots when it sours due to the precipitation of
casein.
Inthis
project we will isolate casein from milk and carry out some qualitative tests
forprotein.The aim of the project is determine quantitatively the percentage of
casein present in three different samples of milk viz., cow, goat and
buffalo.
Contents
|
|
Page
No
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Chapter-1:Introduction
1.1
Milk
1.2
Composition of Milk
1.3
Casein
1.4
Curding of Milk
1.5
Milk and health
|
1
|
|
Chapter-2:
Isolation of Casein
2.1
Objective
2.2 Methodology
2.3
Things Required
2.4
Procedure
2.5
Observation
2.6 Yield
2.7 Precaution
|
|
|
Chapter-3:
Characterization of Casein
3.1 Biuret Test
3.2 Xanthoproteic Test
|
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Chapter-4: Conclusion
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Bibliography
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