2. INTRODUCTION
Milk has been the most widely consumed liquid food source for humans since ancient
times. Among all sources, milk produced from domesticated animals such as cow,
buffalo and goat have been widely consumed by humans depending on the source of
Availability.
Although the importance of milk and its derivatives have been noticed for several hundred
years, recent findings of the impact of minor milk components impact on human health
and nutrition has increased their use in both nutraceutical and therapeutic applications
immunoglobulins (Igs) .
3. GLOBAL PRODUCTION AND MARKET
According to the recent reports released by the International Dairy Federations
the total amount of milk production around the world in 2007 was
approximately 670 million tonnes, and in 2006, it was 661 million tonnes.
The major part of the milk production was from cattle (85%), buffalo (11%), sheep (2%)
and goat (2%).
5. MILK AND ITS COMPONENTS
BOVINE MILK PROTEINS AND SOME OF THEIR PROPERTIES
6. SEPARATION TECHNIQUES USED IN THE DAIRY INDUSTRY TO
EXTRACT MILK PROTEINS:
1.Precipitation :
selective precipitation technique involves adjusting
physical properties of desired
components in crude solutions by addition of organic
solvents, salts, pH changes,
and/or heating to promote selective insolubility or
aggregation. The most common
process of protein precipitation is salting-out at high
concentrations of salt, usually
ammonium sulphate ((NH4)2SO4).
Selective precipitation has been the most commonly
used method in dairy industry for making cheese by
adjusting milk pH below 5 (Acid whey) at 40°C,
which leads to aggregate casein proteins.
7. 2. Membrane filtration
This method based on size of hydrophobicity Membrane processes for
separating milk components operate over a range of particle sizes from 1 nm
to 10 μm .
8.
9. 3.Chromatography:
Ion exchange Chromatography
Just as with other forms of chromatography, ion exchange chromatography utilizes both a
stationary and mobile phase. The stationary phase in this method carries either a positive
or negative charge. The charged stationary phases are named according to the types of
charged particles that bind to them.
Among all, ion exchange chromatography is the most common and popular type of
adsorption chromatography in dairy processing. It is based on the net charge of
components that will bind to the opposite charges present on adsorption surface. Ion
exchange chromatography mainly depends on two factors: the pH and salt
concentration of buffer solutions.
For example, anion exchange adsorption surface
with diethylaminoethyl (DEAE) moieties (+ charge) will facilitate to bind negatively
charged proteins or peptides.
10. Affinity chromatography
Affinity chromatography is an applicable technique used to purify proteins. It is performed
depending on the advantage of the high affinity of proteins for specific chemical groups.
Ingeneral, most commonly used affinity adsorbents for isolation of immunoglobulins
Diethylaminoethyl
group used to bind
negative charge group
Carboxylmethyl group
used to bind positive
charge group
