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Module contents - theoryIntroduction Milk composition
Physiochemical features of milk Milk processingDairy products
manufacturingDairy microbiologyDairy factory and the
environmentQuality assurance of milk & milk products
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4. Milk processingCollection and reception of milk Clarification
Centrifugal separationMembrane filtration
StandardisationHomogenizationPasteurizationSterilizationConcentration
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4. Membrane filtration What is Membrane filtration? Principle
Why needs Membrane filtration? ImportanceMethods of Membrane
filtration? Application
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1. What is Membrane Filtration?Filtration of milk through
various membranesWith various pore sizes and pressuresPermits for
concentrating of milk components Permits for separating of milk
components No use of heat Raw milk Milk constituentsComposition
?Composition ?
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2. Why needs Membrane Filtration?For separating milk
constituents For manufacturing various dairy productsMembrane
Processing permits;Impurity separationWater separation Cream
separationSkim milk separationWhey protein separation Casein
protein separation Lactose separationSpecialized products such as
whey powder, casein powder
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3. Methods of Membrane Filtration? Principle of membrane
processing Reverse of the osmotic pressure Osmotic pressure: When a
solution & water separated by a semi-permeable membraneWater
move into solutionMake equilibrium This is due to Chemical force
caused by concentration gradientKnown as Osmotic pressureReverse
osmosis is the principle of membrane processing
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Cont; Methods of Membrane Filtration? Osmosis & osmotic
pressure
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Cont; Methods of Membrane Filtration? Reverse-osmosis
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If mechanical force > osmotic pressureWater move against
concentration gradient It is Reverse of the osmosis Called Membrane
Processing Particles are separated on Their molecular sizeShape
Technique used Pressure Specially designed semi-permeable
membranesCont; Methods of Membrane Filtration?
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Cont; Methods of Membrane Filtration?
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According to pressure & pore size; 4 types of MPReverse
Osmosis/Hyper-filtration Nano filtrationUltra
filtrationDi-filtration MicrofiltrationCont; Methods of Membrane
Filtration?
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1. Reverse osmosisRO designates a membrane separation
processConcentration of milk by removal of waterDriven by a
pressure gradientIt is a concentration processMembrane separates
water from milk components Membrane pore size is very small Pass
only small amounts of solutes Very low molecular weight solutes Use
cellulose acetate membranes Heat milk to 40CUse composite
membranesHeat milk to 70 to 80C
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Cont; Reverse osmosisConcentrate milk solventMembrane pore size
m Pressure 30 to 60 bars (700 psi)Collect Permeate
Retentate10-4-10-3
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Cont; Reverse osmosis
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2. Nano filtrationConcentration of organic components By removal
of water & mineralsMembrane pore size 10-3-10-2 m -Pressure 20
to 40 bars (470 psi)Membrane materialPolysulfane membranesHeat milk
to 50-60C
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3. Ultra-filtrationConcentration of large and macro
moleculesFatProteinMembrane pore size 10-2-10-1 m Pressure 1 to 10
bars (80 psi)Heat milk to 50-60CLactose & minerals pass into
permeateA 50% separation ratiom
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Cont; Ultra-filtrationIn the retentate would be 100% of fat100%
of protein50% of lactose50% of free minerals
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Di-filtrationA modification of ultra-filtrationRetentate further
diluted with waterRe-ultra filteredReduce the concentration of
soluble permeate componentsIncrease further the concentration of
retained components
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Cont; Di-filtration
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4. Micro-filtration Removal of bacteria & separation of
macro moleculesUse larger membrane pore size 10-1-101 m Allow to
pass particles from 0.2 to 2 micrometersPressure - < 1 bars (15
psi) Heat milk to 50-60CMF use for making low-heat sterile milk As
proteins may pass through but bacteria do not
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Cont; Microfiltration flowchartApplication of Microfiltration in
pasteurized milk manufacturing
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Cont; Methods of Membrane Filtration?
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Cont; Methods of Membrane Filtration?
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Cont; Methods of Membrane Filtration?
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Cont; Membrane filtrations
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Spectrum of application of membrane filtration in dairy
industry
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Batch membrane filtering unit
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Batch membrane filtering unit
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Cont; Membrane filtering unit
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Cont; Membrane filtering unit
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Whey manufacturing by membrane filtering
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Whey/lactose manufacturing by membrane filtering
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DialysisUse the concentration difference as a driving force for
separating large particles from small ones in a solution