This document summarizes different techniques for extracting oil from plant and animal sources. It discusses three main stages of edible oil processing: production of triglyceride oils, refining of oils, and modification of oils. For oil extraction, it describes various methods including rendering, mechanical pressing, and solvent extraction. Mechanical extraction techniques like expression and expellers are explained. Solvent extraction using hexane is described along with factors affecting the process. Other advanced extraction methods like supercritical fluid extraction using carbon dioxide and enzymatic extraction are also summarized.

1. VIDHYALAXMI GROUP OF EDUCATIONAL INSTITUTIONS,
BRAHMAVARA
DEPARTMENT OF FOOD TECHNOLOGY
PRESENTATION
OIL EXTRACTION
MODERATOR
Ms Rasmiya
Lecturer
Technology of Fat and Oil Products
Presented by :
Santhosh Kumar P S
Second year BSc Ft

2. INTRODUCTION
• EDIBLE OIL PROCESSING COVERS THE RANGE OF INDUSTRIAL
PROCESSING THAT THAT START WITH THE ISOLATION OF
TRIGLYCERIDE OILS AND FATS FROM RAW MATERIALS OF
BIOLOGICAL ORIGIN. THIS RANGE INCLUDES THOSE REFINING
PROCESS THAT CONVERT THE CRUDE OIL INTO HIGH QUALITY
OIL PRODUCTS THAT ARE FIT FOR HUMAN CONSUMPTION AND
ALSO THE OIL MODIFICATION PROCESS THAT ENSURE THAT THE
PHYSICAL PROPERTIES IF THE FTS AND OILS MEAT MARKET
REQUIREMENTS AT MINIMAL COST.
• EDIBLE OIL PROCESSING HAS 3 DIFFERENT STAGES.
1. PRODUCTION OF TRIGLYCERIDE OILS.
2. REFINING OF OILS.
3. MODIFICATION OF OILS.

3. OIL EXTRACTION
• OIL EXTRACTION IS THE ISOLATION OF OIL FROM ANIMAL
BYPRODUCTS FLESHY FRUITS SUCH AS THE OLIVE AND PALM, AND
OIL SEEDS SUCH AS COTTON SEED, SESAME SEED, SOYBEANS, AND
PEANUTS.
• OIL IS EXTRACTED BY 3 GENERAL METHODS DEPENDING ON THE
SOURCE OR RAW MATERIAL AND SCALE OF OPERATION.
• RENDERING USED ANIMAL PRODUCTS AND OLIAGINOUS FRUITS.
• MECHANICAL PRESSING FOROIL BEARING SEEDA AND NUTS.
• EXTRACTION WITH VOLATILE SOLVENTS, EMPLOYED IN LARGE
SCALE OPERATIONS FOR MORE COMPLETE EXTRACTION THEN THE
PRESSING.
• OTHER ADVANCED METHODS ARE ALSO EMPLOYED SUCH AS
SUPER CRITICAL FLUID EXTRACTION, ENZYMATIC EXTRACTION,
MICROWAVE ASSISTED EXTRACTION.

4. PRETREATMENT
BEFORE SUBJECTING THE SEEDS TO EXTRACTION PRETREATMENTS
ARE GIVEN TO THE SEEDS TO FACILITATE EASY OIL EXTRACTION.
PRETREATMENTS ARE AS FOLLOWS.
Seed cleaning Dehulling/decorticating Crushing
Cooking or conditioning

5. OIL EXTRACTION TECHNIQUES

6. MECHANICAL EXTRACTION OF OIL
EXPRESSION
• EXPRESSION IS THE PROCESS OF
MECHANICALLY PRESSING LIQUID OUT
OF LIQUID-CONTAINING SOLIDS.
•
• SCREW PRESSES, ROLL PRESSES AND
MILLS, COLLAPSIBLE-PLATE AND FRAME-
FILTER PRESSES, AND HYDRAULIC
PRESSES ARE EXAMPLES OF THE WIDE
VARIETY OF EQUIPMENT AVAILABLE FOR
EXPRESSION PROCESSING.
•
• THE EFFICIENCY OF A MECHANICAL-
EXPRESSION PROCESS CANNOT BE
EQUAL TO UNITY AND, IN ACTUAL
OPERATIONS, IT SELDOM EXCEEDS 90%.
Oil seeds Oil content
Sunflower 40-42
Soybean 13-25
Sesame 50-57
Peanut 43-45
Rapeseed 33-43
Mustard 25-60
Cottonseed 24-26
Coconut 40-45
Caster bean 35-55

7. MECHANICAL EXTRACTION OF OIL
• MECHANICAL OIL EXTRACTION (EXPRESSION) IS A
SOLID-LIQUID PHASE SEPERATION METHOD WHICH
IS APPLIED TO COOKED SEED FLAKES.
•
• • IT CAN BE EXECUTED BY BATCH, MAINLY
HYDRAULIC, AND BY CONTINOUS, MAINLY
MECHANICAL WORKING PRESSES.
•
• THIS METHOD USUALLY USES AN EXPELLER PRESS
TO GIVE PRESSURE ON VEGETABLES, NUTS AND
SEEDS TO CAUSE THE OIL TO RUN.
•
• USUALLY THE MECHANICAL PRESSING METHOD
PROVIDES YIELDS OF ONLY 65-70% OF THE OIL;
AND 80% IS CONSIDERED VERY GOOD.
Most large
commercial
operations use a
mild pressing
operation to
extract 60 to 70%
of the oil, while the
remainder is
solvent extracted.

8. PRESSING
COLD PRESSING
•HIGH OIL CONTAINING SEEDS SUCH AS SESAME AND PEANUTS AND THE
OILY PULPS OF OLIVES YIELD FREE OIL BY THE SIMPLE APPLICATION OF
PRESSURE.
• OIL OF THIS TYPE GENERALLY REQUIRE NO FURTHER PROCESSING.
•SESAME AND PEANUT OILS HAVE A PLEASANT NUTTY FLAVOR.
•OLIVE OIL HAS A STRONG BUT WELL ACCEPTED FLAVOUR.
HOWEVER COLD PROCESSING IS NOT VERY EFFICIENT.

9. HOT PRESSING
✔THE OIL MEALS (SEED RESIDUES FROM WHICH OIL HAS BEEN
REMOVED) OBTAINED AFTER COLD PRESSING TECHNIQUES
CONTAINED AN EXCESSIVE AMOUNT OF VALUABLE OIL.
✔THIS LEAD TO THE DEVELOPMENT OF MORE EFFICIENT PRESSES
SUCH AS THE HYDRAULIC BATCH PRESS AND THE CONTINUOUS
SPIRAL PRESS OR EXPELLER.
✔THESE PRESSES DEVELOP PRESSURE OF 1-15 TONES PER SQUARE
INCH LEAVING 4-5% OIL IN THE MEAL.
✔UNFORTUNATELY SUCH PRESSES ALSO DEVELOP EXCESSIVE HEAT
CAUSING DARKENING OF THE OIL AND DENATURATION OF THE
OILSEED PROTEINS.

10. OIL EXPELLERS USED IN MECHANICAL
EXTRACTION
Screw Press Hydraulic
press

11. • ADVANTAGES OF MECHANICAL EXTRACTIONS
• RELATIVELY SIMPLE PROCESS.
• LOWER INITIAL CAPITAL COST.
• NO USE OF SOLVENT.
• DRAWBACKS OF MECHANICAL EXTRACTIONS
• LOW CAPACITY.
• HIGH RESIDUAL OIL IN THE PRESS CAKE (4 TO 7 %).
• HIGH POWER REQUIREMENTS.
• HIGHER MAINTENANCE AND OPERATOR SKILL.

12. FACTORS AFFECTING MECHANICAL
EXTRACTION OF OIL
Factors Effect
Pressure The more pressure is applied, the
higher is the oil extraction yield.
Temperature The heat coagulates the protein and
reduces the viscosity of oil which
increases the yield.
Prolonged heating at higher
temperature causes hardening of
material that reduces oil yield.
Screw rotation speed Depending upon type of press and
raw material, generally the increase
in screw speed may either increases
or decreases the yield of oil.
Moisture content Low moisture content leads to a
better yield of oil. Higher moisture
results in poor oil recovery.
Particle size Coarser the particle size higher the
yield of oil.

13. SOLVENT EXTRACTION
BASIC PRINCIPLE
THE EXTRACTION OF OIL FROM OILSEEDS BY MEANS OF NON-POLAR
SOLVENTS IS, BASICALLY, A PROCESS OF SOLID-LIQUID EXTRACTION.
THE TRANSFER OF OIL FROM THE SOLID TO THE SURROUNDING OIL-
SOLVENT SOLUTION (MISCELLA) INVOLVES THREE STEPS.
✓ DIFFUSION OF THE SOLVENT INTO THE SOLID,
✓ DISSOLUTION OF THE OIL DROPLETS IN THE SOLVENT, AND
✓ DIFFUSION OF THE OIL FROM THE SOLID PARTICLE TO THE
SURROUNDING LIQUID.

14. FACTORS AFFECTING SOLVENT
EXTRACTION
•PHYSICAL CHARACTERISTICS OF SOLIDS
✓ AN OPEN, POROUS STRUCTURE OF THE SOLID MATERIAL IS
PREFERABLE, BECAUSE SUCH A STRUCTURE FACILITATES DIFFUSION AS
WELL AS PERCOLATION.
•SOLVENT
✓ A SOLVENT HAVING HIGHER SOLUBILITY IS PREFERABLE. A LOW
BOILING POINT MAKE THE SEPARATION EASIER.
• TEMPERATURE
✓ THE RATE OF EXTRACTION CAN BE INCREASED CONSIDERABLY BY
INCREASING THE TEMPERATURE IN THE EXTRACTOR.
✓ HIGHER TEMPERATURE MEANS HIGHER SOLUBILITY OF THE OIL, HIGHER
DIFFUSION COEFFICIENTS AND LOWER MISCELLA VISCOSITY.
* A NUMBER OF PROCESSES LIKE COOKING, FLAKING HAVE BEEN
PROPOSED FOR INCREASING THE POROSITY OF OILSEEDS BEFORE
SOLVENT EXTRACTION.

15. CHOICE OF SOLVENT
AN IDEAL SOLVENT FOR THE EXTRACTION OF OIL FROM OIL SEEDS SHOULD POSSESS THE
FOLLOWING PROPERTIES
✔ GOOD SOLUBILITY OF THE OIL.
✔ POOR SOLUBILITY OF NON-OIL COMPONENTS.
✔ HIGH VOLATILITY (I.E. LOW BOILING POINT), SO THAT COMPLETE REMOVAL OF THE
SOLVENT FROM THE MISCELLA AND THE MEAL BY EVAPORATION IS FEASIBLE AND EASY.
✔ THE BOILING POINT SHOULD NOT BE TOO LOW, SO THAT EXTRACTION CAN BE CARRIED
OUT AT A SOMEWHAT HIGH TEMPERATURE TO FACILITATE MASS TRANSFER.
✔ LOW VISCOSITY.✓ LOW LATENT HEAT OF EVAPORATION, SO THAT LESS ENERGY IS NEEDED
FOR SOLVENT RECOVERY.
✔ LOW SPECIFIC HEAT, SO THAT LESS ENERGY IS NEEDED FOR KEEPING THE SOLVENT AND
THE MISCELLA WARM.
✔CHEMICALLY INERT TO OIL AND OTHER COMPONENTS OF THE SEED FLAKES.
✔ABSOLUTE ABSENCE OF TOXICITY AND CARCINOGENICITY, FOR THE SOLVENT AND ITS
RESIDUES.
✔ NON-INFLAMMABLE, NON-EXPLOSIVE, NON-CORROSIVE.
✔COMMERCIAL AVAILABILITY IN LARGE QUANTITIES AND LOW COST.

16. DVANTAGES AND DISADVANTAGES OF TH
SOLVENT EXTRACTION PROCESS
ADVANTAGES
⚫ HIGH OIL YIELD AS COMPARED TO MECHANICAL EXTRACTION. .
⚫ SPENDS LOWER PRODUCTION COST AND REQUIRES LESS TIME.
DISADVANTAGES
⚫ THE EXPELLER PRESSED OIL IS CLEANER MORE PURE OIL, HIGHER IN NATURAL
COLORS AND FLAVORS COMPARED TO THE SOLVENT EXTRACTED OIL.
⚫ REQUIREMENT OF LARGE VOLUME OF SOLVENT, PRESSURE REQUIREMENTS, ETC.
⚫ HIGH CONSTRUCTION COST OF EXTRACTION AND REFINING WORKSHOP.
⚫ HIGH MAINTENANCE COST.
⚫ RESIDUAL OIL CONTENT IN MEAL.

17. TYPES OF EXTRACTORS
SOLVENT EXTRACTORS ARE OF TWO TYPES
BATCH TYPE
✓ IN BATCH PROCESSES, A CERTAIN QUANTITY OF FLAKES IS CONTACTED WITH A CERTAIN VOLUME OF FRESH
SOLVENT.
✓ THE MISCELLA IS DRAINED OFF, DISTILLED AND THE SOLVENT IS RECIRCULATED THROUGH THE EXTRACTOR UNTIL
THE RESIDUAL OIL CONTENT IN THE BATCH OF FLAKES IS REDUCED TO THE DESIRED LEVEL.
CONTINUOUS TYPE
✓ BOTH THE OILSEEDS AND THE SOLVENT ARE FED INTO THE EXTRACTOR CONTINUOUSLY.
✓ THE DIFFERENT AVAILABLE TYPES ARE CHARACTERIZED BY THEIR GEOMETRICAL CONFIGURATION AND THE
METHOD BY WHICH SOLIDS AND SOLVENTS ARE MOVED, ONE IN RELATION TO THE OTHER.
* CONTINUOUS SOLVENT EXTRACTORS ARE OF TWO TYPES
✓ PERCOLATION TYPE
✓ IMMERSION TYPE

18. SIMPLIFIED FLOW DIAGRAM OF A
HEXANE EXTRACTION PROCESS

19. SUPERCRITICAL FLUID EXTRACTION
• PUBLIC CONCERNS AND GOVERNMENT SCRUTINY ABOUT THE ENVIRONMENTAL AND
HUMAN HEALTH HAZARDS OF ORGANIC SOLVENTS AND RESIDUES IN OIL/OILSEED-
DERIVED PRODUCTS HAVE CATALYZED THE SEARCH FOR ALTERNATIVE SOLVENTS
FOR EDIBLE OIL PROCESSING. ETHANOL, ISOPROPYL ALCOHOL, ACETONE, ISO-
HEXANE AND SUPERCRITICAL FLUIDS (SCF) HAVE BEEN STUDIED AS ALTERNATIVE
SOLVENTS. SCF TECHNOLOGY HAS BEEN EXAMINED AS AN ALTERNATIVE TECHNIQUE
FOR THE CONVENTIONAL OIL AND OILSEED PROCESSING METHODS FOR MORE
THAN TWO DECADES. THE SUPERCRITICAL CARBON DIOXIDE (SC-CO2) TECHNIQUE,
WHICH UTILIZES CARBON DIOXIDE ABOVE ITS CRITICAL PRESSURE (7.3 MPA) AND
TEMPERATURE (31°C) AS SOLVENT, HAS BEEN THE CHOICE FOR THE MAJORITY OF
EDIBLE APPLICATIONS. THE UNIQUE ADVANTAGE OF SC-CO2 IS THE EASY REMOVAL
OF SOLVENT FROM THE EXTRACT. WHEN PRESSURE IS RELEASED FROM THE SYSTEM,
CARBON DIOXIDE RETURNS TO THE GAS PHASE AND OIL PRECIPITATES OUT FROM
CO2-OIL MIXTURE. CARBON DIOXIDE IS RECYCLED; HENCE, CO2 RELEASED FROM
THE SYSTEM IS NOT AN ENVIRONMENTAL ISSUE. ALTHOUGH INDUSTRIAL
APPLICATIONS OF SC-CO2 TECHNOLOGY HAVE BEEN GROWING STEADILY,
CURRENTLY MOST OF THE APPLICATIONS INVOLVE HIGH-VALUE PRODUCTS. THE
ECONOMIC FEASIBILITY OF SC-CO2 BASED PROCESSES IS STILL HAMPERED BY THE
CAPITAL COST OF HIGH PRESSURE VESSELS. HOWEVER, COST SAVING CAN BE
REALIZED FROM SIMPLIFIED SEPARATIONS AND THE LOWER SOLVENT COST OF
SUPERCRITICAL FLUIDS. THE NONTOXICITY OF SC-CO2 AND SIGNIFICANTLY
REDUCED WASTE STREAMS FROM THE PROCESS MAKES THIS TECHNOLOGY UNIQUE
IN TERMS OF MEETING INCREASINGLY STRINGENT HEALTH AND ENVIRONMENTAL

20. LOW DIAGRAM OF A SUPERCRITICAL CARBON DIOXIDE
EXTRACTION SYSTEM.

21. AQUEOUS ENZYMATIC EXTRACTION
•THE EXTRACTION OF OIL FROM EDIBLE AND NON-EDIBLE
OILSEEDS BY SOLVENT EXTRACTION STEP BY MECHANICAL
AND CHEMICAL FOR INDUSTRIAL PURPOSE. NORMALLY,
HEXANE IS USED AS A SOLVENT.
•IN THE PAST, DUE TO USE OF HEXANE, THERE IS CHANCES OF
ENVIRONMENTAL POLLUTION AND LOW OIL YIELD. SO USE OF
HEXANE WAS REDUCED.
•THE PRESENT SCENARIO TO BE CHANGING. INTEREST IN
AQUEOUS ENZYMATIC EXTRACTION PROCESSES HAS BEEN
BECOMING POPULAR DUE TO ITS ENVIRONMENTAL
CONCERN. AN AQUEOUS PROCESS IS LOOKED UPON AS
ECOFRIENDLY TECHNOLOGY FOR OIL EXTRACTION.

22. • OTHER ADVANTAGES OF THE AQUEOUS ENZYMATIC
EXTRACTION PROCESS COMPARED WITH SOLVENT-BASED
PROCESSES INCLUDE:
• (I) HIGHER EXTRACTION OF EDIBLE AND NON-EDIBLE OIL
AND PROTEIN
• (2) MINIMUM DAMAGE OF PROTEIN DURING EXTRACTION, AND
• (3) GOOD PROCESS SAFETY DUE TO THE MINIMUM FIRE RISK
AND EXPLOSION. DUE TO THE SOLVENT RECOVERY STEP IS
ELIMINATION, AQUEOUS EXTRACTION PROCESSES MAY BE
MORE COST EFFECTIVE.

23. • THEENZYMATICHYDROLYSIS PROCESS ISTHE PRETREATMENT OFOILSEEDS WITHENZYMES. THISLEADSTOAQUICK
SOFTENINGOFOILSEED COATS.INOTHERWORDS,ENZYMES DIGEST THECOMPLEXCELLWALLSOFOILSEEDS WHICHINCREASES
THEIR PERMEABILITY LEADINGTOBETTER OILEXTRACTION.THEY OPENUPOILCELLWALLSANDBREAKTHECOMPLEX
LIPOPROTEINANDLIPO-POLYSACCHARIDE MOLECULES INTOSMALLPARTSWHICHCANBEPROCESSED FURTHER.THESE LEAD
TOARELEASE OFOILFROMLIPIDBODIES TRAPPEDBETWEEN CARBOHYDRATE ANDPROTEINSTRUCTURES WITHINTHESEEDS.
• ENZYMATICEXTRACTION OFOILREQUIRES CERTAINFACTORSLIKETEMPERATURE, OPTIMUMPHLEVELS,MOISTURE, GRINDING,
ANDREDUCED SIZEOFOILSEEDS FORTHEIREFFICIENT WORKING.THISLEADSTOEFFICIENT ANDINCREASED EXTRACTION OF
OILWITHAHIGHERCONCENTRATION OFNUTRIENTS.
• UTILIZINGENZYMES FOROILEXTRACTION ISANECO-FRIENDLY PROCESS THATREDUCES BOD(BIOLOGICALOXYGENDEMAND)
BY75%ANDCOD(CHEMICALOXYGENDEMAND) UPTO45%OFTHERESIDUE ANDWASTEWATER GENERATED. ENZYME
EXTRACTION ALSOLOWERSACIDDEVELOPMENT ANDOXIDATIONWHICHMAY OCCURDURINGFURTHERPROCESSING AND
STORAGE.

24. ENZYMES USED IN OIL EXTRACTION
• DIFFERENT ENZYMES ARE USED DEPENDING ON THE OILSEEDS
AND THE EXTRACTION PROCESS USED FOR OIL RECOVERY.
ENZYMES SUCH AS PROTEASES, CELLULASES, AND
HEMICELLULASES ARE USED FOR IMPROVED RECOVERY OF OIL
FROM SOLVENT AND EXPELLERS EXTRACTION METHODS.
PECTINASE AND CELLULASE ARE THE MOST EFFECTIVE ENZYMES
THAT INCREASE OIL RECOVERY BY NEARLY 20%. ENZYMATIC
EXTRACTION OF OIL SHOULD PRIMARILY CONTAIN A
COMBINATION OF SEVERAL ENZYMES LIKE CELLULASES,
HEMICELLULASES, PECTINASES, AND PROTEASES. OTHER ENZYMES
USED FOR THE EXTRACTION OF EDIBLE OILS COULD INCLUDE
POLYGALACTURONASE, ALPHA-AMYLASE, CARBOHYDRASES, AND
GALACTOMANASE.