Get familiar with the traditional or local and modern methods of crude palm oil extraction from the oil palm fruit.
Both traditional and modern methods achieve crude palm oil extraction. While the traditional method is tedious and requires manpower, the modern method is either automated or semi-automated.
In my local community in Nigeria, we smallholder farmers use the agelong traditional methods that require manpower to extract the golden oil before processing it into red palm oil.
This article will look closely at these two methods and how they play out in the extraction process, including their benefits and drawbacks.
Related: What is Palm Oil?
Key Takeaways
- Crude palm oil processing and extraction involve traditional local methods and modern techniques.
- Local palm fruit oil processing and extraction methods are labor-intensive and time-consuming but preserve traditional knowledge.
- Local processing of crude palm oil involves steps such as harvesting, stripping, threshing, steaming, milling, and pressing.
- Advantages of modern methods of processing palm fruit oil include higher efficiency, improved quality, consistency, speed, sustainability, labor reduction, and safety, but come with high initial investment and complexity.
Related: Benefits of Palm Oil
Table of Contents
- Key Takeaways
- Local Method of Crude Palm Oil Extraction
- Advantages of the Local Extraction of Palm Fruit Oil
- Disadvantages of the Local Extraction of Palm Fruit Oil
- The Modern Method of Palm Fruit Oil Processing and Extraction
- Advantages of the Modern Method of Processing and Extraction of Crude Palm Oil
- Disadvantages of the Modern Method of Processing and Extraction of Crude Palm Oil
- Solvent Extraction of Crude Palm Oil
- Advantages of the Solvent Extraction of Crude Palm Oil
- Disadvantages of the Solvent Extraction of Palm Fruit Oil
- Factors Affecting Crude Palm Oil Quality
- Frequently Asked Questions on Extraction of Crude Palm Oil
- Final Word from PalmOil Pathway
Recommended: What is Refined Palm Oil?
Local Method of Crude Palm Oil Extraction
The local method of processing crude palm oil is a traditional and sustainable way of producing palm oil in rural areas – my community in Nigeria.
This method produces two types of crude palm oil – the primary palm crude extract and the secondary palm crude extract.
The Primary Palm Crude Extract
The primary crude palm oil extract is obtained from the initial pressing of the mesocarp pulp of oil palm fruits during the milling process.
This extract is rich in triacylglycerols, giving it a high oil yield, and retains its characteristic deep reddish-orange color due to carotenoids.
It contains natural impurities, such as moisture, free fatty acids, and small amounts of solid particles.
This raw oil serves as the foundation for producing refined palm oil or red palm oil.
The primary extract is highly valued for its rich nutrient content, including vitamin A precursors, and is widely used in food and industrial applications.
Related: Fatty Acids in Palm Crude Oil
Secondary Crude Palm Oil Extract
The secondary crude palm oil extract is obtained by further processing palm oil milling residues, such as palm oil mill effluent (POME), fiber, and pressed chaff.
It involves recovering residual oil trapped in these by-products, typically through mechanical pressing, decantation, or solvent extraction.
This oil is of lower quality compared to the primary extract, as it contains higher levels of impurities, moisture, and free fatty acids.
While not directly suitable for culinary purposes, secondary crude palm oil finds applications in industrial uses, such as biodiesel production, soap-making, and animal feed, ensuring minimal wastage in palm oil milling processes.
The processing of palm oil involves several steps, including:
- Harvesting
- Stripping/cutting the spikelets
- Threshing
- Steaming
- Pounding/milling
- Second threshing
- Pressing
- Clarification/filtering
- Storage
Harvesting Palm Fruit Bunches
The first step in the local method of extracting crude palm oil is harvesting the ripe fresh fruit bunches from the palm tree.
The fruits are harvested by hand for short palm trees or with a special rope used by South Eastern Nigerians to climb the tall palm trees to cut the bunches down (see photo).
The bunches are transported by wheelbarrow or on the head to the processing site which is usually a designated area around the home or to a locally constructed mill.
Related: Is Palm Oil Bad for You?
Stripping/Cutting of the Spikelets from the Stalk
After harvesting, the palm fruit bunches are stripped by matches or axes to free the spikelets from the stalk.
This is achieved with a sharp matchet, with the bunch held vertically with the head of the stalk upwards and cutting from the base where the spikelets start and work downwards.
The spikelets are the thorn-laden smaller stalks that hold the palm fruits. The spikelets are attached to the bigger stalk that forms the bunch. See palm fruit bunch here.
When all the spikelets are removed, what remains would be a fibrous stalk that is also useful along the palm oil value chain.
The spikelets which hold the fruits are spread, covered, and left to sit for a few days usually 5 to 7 days so the fruits can be easily removed from the spikelets after heat has done its thing.
Related: Hydrogenated Palm Oil and the Process
Picking Palm Fruits and Threshing the Husks from the Palm Fruit Spikelets
After stripping, threshing which is the separation of the fruits from the spikelets is now very easy after the waiting period.
This is achieved either by picking the fruits one by one or by hitting them with a stick to remove them from the spikes.
When the fruits are separated from the spikes, some other smaller residues like the husk must also be removed by flail or throwing the fruits over a flatbed mesh with tiny holes enough for the husks to pass through while the heavier fruits are collected at the other end.
After picking the palm fruits, they are transferred into a giant boiling pot to be cooked before pounding or milling.
It is important to point out that these processes can take days to be completed. The palm fruit is a very resilient fruit that can go for days without going bad.
Related: Palm Oil in the Making of Soaps
Boiling/Steaming/Sterilizing the Palm Fruits
Yes! The palm fruits are transferred to a large drum-pot filled with water halfway with a massive fire underneath and steamed for 2 hours.
This process helps to soften and break down the oil-bearing cells in the fruit, making it easier to extract the pulp and the kernel.
Recommended: Are Crude Palm, Red Plam, and Refined Palm Oils the Same?
Local Milling of Palm Fruits
Milling is a very important step in local or traditional crude palm oil extraction. It can be achieved either by pounding or a mill.
Pounding
Pounding is a method of milling that is achieved by transferring the cooked palm fruits into a huge wooden or iron mortar and pounding repeatedly with a long pestle until completely mashed.
When this is done, you can see the crude palm oil dripping from the pestle and ready to be pressed.
Locally Constructed Milling Machine
Another milling method is with a locally constructed milling machine that is powered by a diesel generator with a motor that is connected to the miller drum motorized with a belt.
Inside the thick drum are a combination of turning blades and blunt edges that go opposite directions to rob the soft palm fruits together, crushing the mesocarp but not the kernel to free the crude pulp.
Because the pulp is slippery as a result of the oil content, special sands are added to introduce friction so it can be properly milled.
Marching Method
Also, another method used by people who don’t have a locally constructed miller to extract crude palm oil is the marching method.
In this method, after the palm fruits are steamed, they are transferred into a big pit specially prepared for milling by marching.
Feet is used to match the soft palm fruits until the mesocarps are completely milled resulting in the fiber-pulp-palm-crude mixture ready to be pressed.
This fibrous mixture of oil, chaff, pulp, kernel, and water is called palm oil mill effluent (POME).
Related: Oil Palm Fruits: Everything to Know
Kernel Removal from Palm Oil Mill Effluent
After the palm fruit has been milled to satisfaction, the next step is to remove the kernels from the palm oil mill effluent before the mechanical press.
The kernel is a hard nut at the core of the palm fruit which does not allow the palm oil mill effluent mixture to be pressed properly, so it must be removed.
This is done by using locally made special tools to separate the kernels from the effluent. After this is done, the mechanical press can then happen.
Mechanical Press to Release the Primary Palm Crude Oil
There are two methods we use in pressing the first crude palm oil extract out from the pulp and fiber mixture.
Mechanical Press Using a Porous Bag
In the porous bag method, the palm oil effluent mixture is transferred into a large porous bag and tied. It is then subjected to pressure to let the crude palm escape through the small holes.
This is inefficient as the mixture is not completely pressed. However, after pressing, the remaining is put in water and separated through the local centrifuge.
Mechanical Press Using a Locally Made Machine
The second method is more efficient with the use of a steel mechanical presser. It consists of a large drum with holes by the sides. The drum sits on a round bed with one opening at the side for collecting the crude palm oil.
The top is a lid that can be screwed up and down to exert pressure on the effluent to release the crude palm oil.
This is the most efficient in my palm oil community and is fast replacing the first method.
The final primary palm crude extract is a dense, deep-orange oil with a viscous texture and distinct earthy aroma.
Its physical properties include a melting point between 33°C and 39°C and a semi-solid state at room temperature.
Chemically, it is composed primarily of fatty acids – triacylglycerols (90–95%), with nearly equal proportions of saturated (palmitic acid, ~45%) and unsaturated fats (oleic acid, ~40%).
It is rich in carotenoids (500–700 ppm), which give it its vibrant color, and tocopherols and tocotrienols (vitamin E compounds), contributing to its antioxidant properties.
It also contains free fatty acids (3–5%), moisture, and minor impurities like phospholipids.
The Secondary Palm Oil Crude Extract
The local process of extracting secondary crude palm oil involves recovering residual oil from palm oil mill by-products, such as fibers, nuts, and effluent.
First, the residue is collected after the primary extraction process.
The material is then boiled to soften and loosen the remaining oil. Next, the boiled mixture is pressed manually or using simple mechanical devices to extract the oil.
The pressed liquid, which contains oil, water, and impurities, is decanted or filtered to separate the crude oil.
This method is labor-intensive and yields oil with higher impurities, primarily used for industrial purposes or further processing.
As we have seen, the crude palm oil obtained by pressing palm oil mill effluent (POME) is an extract characterized by its high impurity content.
This oil is darker in color, with a mix of water, solids, and residual fats from the milling process.
It contains a good percentage of free fatty acids (FFAs), making it less suitable for direct consumption without further refining. However, it retains valuable components such as carotenoids and tocopherols.
This secondary crude oil is commonly used in industrial applications, including biofuel production, soap manufacturing, and animal feed, after appropriate processing.
Related: Impacts of Palm Oil Deforestation
Advantages of the Local Extraction of Palm Fruit Oil
Local processing and extraction methods of crude palm oil, despite their challenges, offer several distinct advantages that contribute to the sustainability and livelihoods of communities involved in palm oil production.
- Preservation of Traditional Knowledge: Local palm oil processing protects cultural heritage, sustains traditional knowledge, and supports local livelihoods through community-based production methods.
- Support for Small-Scale Producers: Small-scale palm oil extraction empowers rural producers, boosting local economies and providing income for families in underprivileged communities.
- Reduced Environmental Footprint: Using organic waste for composting and mulching, local processing reduces waste and improves soil fertility, creating a more sustainable system.
- Beneficial to Biodiversity: Sustainable practices like intercropping and agroforestry in small-scale operations promote biodiversity and strengthen ecosystem health.
- Flexibility and Adaptability: Local processors adjust methods to suit market demands and environmental changes, ensuring timely and efficient production.
- Application of Traditional Knowledge: Integrating traditional knowledge with modern techniques enhances local processing efficiency and product quality, fostering innovation and sustainability.
Disadvantages of the Local Extraction of Palm Fruit Oil
While local processing and extraction of crude palm oil methods have been the backbone of palm oil production for generations, they come with a set of challenges and disadvantages.
Understanding these drawbacks helps to address the inefficiencies and environmental impacts associated with local palm oil production.
- Inefficiency in Oil Extraction: Manual processing methods lead to low efficiency and significant oil losses, limiting productivity for local palm oil producers.
- Poor Oil Yield: Traditional techniques fail to fully extract oil, reducing yields and affecting small-scale producers’ ability to meet economic demands.
- Inconsistent Quality: Without standardized processes, local palm oil varies in quality, reducing marketability and competitiveness against industrially processed alternatives.
- Environmental Impact: Open burning and poor waste management from local processing contribute to pollution and environmental degradation, worsening ecological concerns.
- Labor-Intensive and Time-Consuming: Manual processing is slow and exposes workers to health risks, limiting production scalability for small-scale palm oil producers.
- Limited Access to Technology: High costs and low technical knowledge restrict small producers’ access to advanced tools, reducing efficiency and competitive growth opportunities.
- Economic Constraints: Inconsistent yields and global price fluctuations hurt small producers’ incomes and financial stability, hindering their sustainability.
The Modern Method of Palm Fruit Oil Processing and Extraction
Technological advancements in the palm oil industry have modernized the processes of producing crude palm oil starting from planting to harvesting and down to refining.
The stages in the modern processing and extraction of crude palm oil are the same as in the traditional method.
The only difference is that the modern method is automated or semi-automated.
Let’s take a closer look:
Modern Method for Harvesting Fresh Fruit Bunches from Palm Trees
In the modern processing of crude palm oil, harvesting is done with special equipment – a long pole with moving blades or sickle attached at the end that cuts the bunch’s neck without much effort from the operator.
The length of the harvester can be extended up to 12 feet for taller palm trees. It is powered by a petrol engine at the base with buttons at the disposal of the operator.
Once the fruit has been harvested, it is transported to the processing plant with a bucketed tractor where it awaits the next process.
Modern Method of Sterilizing Fresh Fruit Bunches
After harvesting, palm fruit oil is sterilized using a vertical sterilizer that employs steam and water.
The process begins by feeding fruit bunches through an inlet with the blowdown and bleed-off valves closed, while the water valve is opened. This allows water to enter the sterilizer, displacing the air and steam inside.
This method ensures the fruits are adequately sterilized for easier digestion and higher-quality oil extraction.
The idea is to heat the fresh fruit bunches to a high temperature to kill any bacteria and enzymes that may affect the quality of the oil.
Modern Threshing Machine
The palm fruit thresher machine features a revolving drum that collects the bunches and tosses them in a centrifugal, rotational movement, effectively separating the fruits from the bunches.
Modern Digesting Machine in Crude Palm Oil Extraction
The digestion process in palm crude oil extraction is achieved by feeding the threshed palm fruits into a digester with rotating arms that crush and break down the pulp (mesocarp), releasing trapped oil.
The pulp is steamed, in combination with vigorous stirring to stimulate uniformity and the release of the oil and it is ready for pressing.
Crude Palm Oil Extraction/Pressing
After digestion, oil extraction from fresh fruit bunches involves mechanical pressing or centrifugation.
The heated and softened pulp is fed into a screw press, where high pressure squeezes out the crude palm oil.
Alternatively, centrifugation separates the oil from the pulp using rapid spinning, exploiting density differences.
After pressing out the crude palm oil, the fiber and kernels are further put into water and decanted to remove the remaining oil before threshing out the kernels from the fiber.
Both methods ensure efficient separation of oil from the fibrous material and water.
Clarification of Extracted Palm Fruit Oil
Once the oil has been extracted, it is sent to a clarification tank where any impurities are removed.
This is done using centrifuges or separation tanks, which separate the oil from any water or solids that may be present.
Storage of Freshly Extracted Crude Palm Oil
After extraction, clarified crude palm oil is stored in large tanks to allow any remaining impurities to settle.
This ensures the oil is stable and maintains its quality. Once settled, the oil is transferred into appropriate containers for packaging.
These containers, often drums or large plastic vessels, are designed to protect the oil from contamination and oxidation.
The packaged oil is then either sold as crude palm oil or sent for further refining, depending on its intended use.
Proper storage and packaging are important to preserving the oil’s quality and extending its shelf life.
Advantages of the Modern Method of Processing and Extraction of Crude Palm Oil
1. Higher Efficiency: Modern methods, including mechanical pressing and solvent extraction, maximize oil yield from the fruit, ensuring minimal waste.
2. Improved Quality: Advanced techniques in sterilization, digestion, and extraction lead to higher-quality crude palm oil with fewer impurities.
3. Consistency: Automation and precise control over processing parameters ensure consistent oil quality and characteristics.
4. Speed: Modern equipment and processes significantly reduce the time required for extraction and processing, increasing throughput.
5. Sustainability: Modern methods often incorporate sustainable practices, such as using renewable energy sources and efficient resource management, reducing the environmental impact.
6. Labor Reduction: Automation reduces the need for manual labor, decreasing labor costs and mitigating risks associated with labor-intensive processes.
7. Safety: Improved machinery and safety protocols minimize the risk of accidents and enhance the overall safety of the processing environment.
Disadvantages of the Modern Method of Processing and Extraction of Crude Palm Oil
1. High Initial Investment: The setup cost for modern processing facilities, including advanced machinery and infrastructure, can be substantial.
2. Complexity: Modern methods require specialized knowledge and technical expertise to operate and maintain advanced equipment.
3. Energy Consumption: Some modern techniques, especially those involving mechanical and thermal processes, can be energy-intensive, potentially increasing operational costs.
4. Regulatory Compliance: Modern processing methods must adhere to strict regulatory standards, which can be complex and costly to maintain.
5. Maintenance and Repairs: Advanced machinery requires regular maintenance and can be costly to repair, leading to potential downtime and increased operational expenses.
Solvent Extraction of Crude Palm Oil
Solvent extraction is a technique used to separate a particular compound from a mixture based on the solubility of the compound in a specific solvent.
In the case of palm oil extraction, a solvent such as hexane is often used to dissolve the oil from the fresh fruit bunches.
This method is highly efficient and has been proven to yield a higher quantity of oil compared to other conventional methods.
The process of solvent extraction begins by first crushing the fresh fruit bunches to release the oil.
The crushed fruit is then subjected to a series of treatments to remove impurities and moisture.
Once the oil is separated from the other components of the fruit, it is mixed with the solvent and heated to facilitate the dissolution of the oil.
The mixture is then filtered to remove any remaining solids and the solvent is then evaporated to leave behind pure crude oil palm.
Advantages of the Solvent Extraction of Crude Palm Oil
1. Higher Oil Yield: One of the major advantages of solvent extraction is that it allows for a higher oil yield compared to traditional methods such as mechanical press.
2. Faster: It is also a faster process, which makes it more efficient for large-scale palm oil production.
3. Preservation of Quality and Flavour: It also helps to preserve the quality and flavour of crude palm oil by minimizing oxidation and the formation of free fatty acids.
Disadvantages of the Solvent Extraction of Palm Fruit Oil
1. Negative Environmental Impact: One of the main concerns with this method is the potential environmental impact of using chemical solvents such as hexane.
2. A Must for Proper Safety Measures: Proper safety measures must be in place to ensure that the solvent is handled and disposed of properly to prevent any harm to the environment.
Factors Affecting Crude Palm Oil Quality
The quality of crude palm oil is affected by many factors, including the variety of oil palm, the growing conditions, and the processing methods used, but here are some of the key factors:
1. Fruit Ripeness
The ripeness of the palm fruit significantly influences oil quality. Over-ripe or under-ripe fruits can result in lower oil yields and produce oil with inferior characteristics, including higher free fatty acids and off-flavors, compromising the overall quality of crude palm oil.
2. Harvesting and Transportation
Rough handling or delays during harvesting and transportation can cause physical damage to the fruits and initiate premature oil degradation.
This results in increased free fatty acid content, leading to lower-quality crude palm oil and potentially higher refining costs.
3. Processing Conditions
Processing conditions such as sterilization, digestion, and pressing are crucial for oil quality. Improper sterilization can leave harmful enzymes active, while poor digestion or pressing can result in lower yields and oil with higher impurities and off-flavors, affecting overall quality.
4. Storage Conditions
Proper storage conditions are vital for maintaining oil quality. High temperatures or humidity during storage can accelerate oil degradation, leading to rancidity and microbial contamination.
These factors significantly affect the stability, taste, and shelf life of crude palm oil.
Frequently Asked Questions on Extraction of Crude Palm Oil
Is palm fruit oil bad for you?
Palm fruit oil is high in saturated fats, which can impact heart health if consumed excessively. Moderation is key to a balanced diet.
What is the modern method of crude palm oil extraction?
The modern method of palm oil extraction uses mechanical pressing, solvent extraction, and advanced machinery for efficient, high-yield, and consistent oil production.
How is crude palm oil extracted?
Crude palm oil is extracted by sterilizing, digesting, and mechanically pressing or centrifuging the fruit pulp to separate the oil from the solids.
What is the traditional method of oil processing crude palm oil?
The traditional method involves manual threshing, boiling, and mechanical pressing of the fruit pulp to extract crude palm oil, requiring intensive labor and time.
What is the process of oil palm?
The process includes cultivating palm trees, harvesting fruit bunches, sterilizing, threshing, digesting, extracting oil, and refining crude palm oil for various uses.
Final Word from PalmOil Pathway
Crude palm oil processing and extraction can be achieved through both traditional local methods and modern sophisticated techniques.
While traditional methods preserve cultural heritage and support small-scale producers, they also come with inefficiencies and environmental impacts.
On the other hand, modern methods offer higher efficiency, improved quality, and sustainability but require high initial investments and specialized knowledge.
Both methods have their advantages and disadvantages, highlighting the need for a balance between tradition and innovation in the palm oil industry to ensure sustainability and quality.
Citations:
- https://www.palmoilmillplant.com/faqs/how-palm-oil-extracting-plant-works.html
- https://www.foodunfolded.com/article/palm-oil-how-its-made
- https://www.agrifarming.in/palm-oil-extraction-process-methods-steps
