How to Choose the Right Processing Method for Different Oilseeds? Rapeseed, Soybean, and Peanut Each Have Their Own Answer

Hundreds of millions of tons of oilseeds are processed globally each year, but there is no “one-size-fits-all” processing method. Soybeans are best suited for direct solvent extraction, rapeseed requires pre-pressing followed by extraction, while peanuts and sesame are better processed by pressing to preserve their distinctive flavors.

Why can’t a single set of processing equipment handle all oilseeds? The answer lies in the oil content and quality characteristics of each seed. This article starts with the oil content data of various oilseeds and systematically analyzes the optimal processing routes and equipment configurations for different oilseeds.

I. Oil Content Determines the Processing Route – The First Principle

The golden rule of oilseed processing is: the higher the oil content, the more pressing is needed first; the lower the oil content, the more suitable it is for direct extraction.

The oil content of major oilseeds varies significantly:

Oilseed	Oil Content Range	Recommended Process
Soybean	15%-26%	Direct solvent extraction
Rapeseed	33%-50%	Pre-pressing + extraction
Peanut	40%-51%	Pressing (mainly hot pressing)
Sunflower (oil type)	45%-54%	Pre-pressing + extraction
Sesame	45%-63%	Pressing (cold pressing / water method)
Cottonseed	15%-25%	Direct extraction or pre-pressing + extraction
Rice bran	14%-24%	Direct extraction

Oil content not only determines the process route but also directly affects the configuration of the complete oil processing equipment – from pretreatment to pressing and then to extraction, different oilseeds require completely different equipment combinations.

II. Soybean – Low Oil Content, Extraction Is the Mainstream

Soybean has an oil content of approximately 15%-26%, making it a typical low-oil-content oilseed. The primary value of soybean lies not only in its oil but also in its protein (content as high as 35%-45%).

Why isn’t pure pressing used for soybeans?

With its relatively low oil content, pure pressing leaves 6%-10% residual oil in the meal, which not only wastes oil but also reduces the protein concentration of the meal. Solvent extraction can reduce residual oil to below 1% while producing high-protein soybean meal.

Standard soybean processing configuration:

Pretreatment: Cleaning screens remove impurities → Destoners separate stones → Magnetic separators capture metal → Crushers break the beans → Conditioners adjust temperature and moisture → Flaking mills roll into 0.25-0.35 mm flakes
Extraction: Rotocel extractors or drag chain extractors for solvent extraction
Desolventizing: DTDC desolventizer-toasters remove residual solvent
Refining: Degumming tanks, alkali refining tanks, bleaching towers, and deodorization towers complete the refining process

It is worth emphasizing that extraction yields approximately 50% more oil than pressing – this is the fundamental reason why direct extraction is the preferred method for soybean processing.

III. Rapeseed – High Oil Content, Pre-Pressing + Extraction

Rapeseed has an oil content as high as 33%-50%, making it a typical high-oil-content oilseed.

Why can’t rapeseed be directly extracted?

If high-oil-content oilseeds are fed directly into extraction equipment, the high oil concentration makes solvent penetration difficult and reduces extraction efficiency. Therefore, the industry uses a pre-pressing + extraction combination process.

Standard rapeseed processing workflow:

Step 1 (Pre-pressing): After pretreatment, rapeseed is fed into screw presses for pre-pressing, extracting approximately 60%-70% of the oil
Step 2 (Extraction): The pressed cake (still containing 12%-18% oil) is sent to extraction equipment to recover residual oil using solvent, with total residual oil reduced to below 1%
Step 3 (Refining): Crude oil is processed through refining equipment – degumming, deacidification, bleaching, and deodorization – to become finished oil

This “press first, then extract” combination strategy ensures both high oil yield and oil quality. Studies have shown that the pre-pressing + extraction combination process can bring the total oil yield of rapeseed close to the theoretical upper limit of its oil content.

IV. Peanut – Flavor First, Pressing Is the Way to Go

Peanut has an oil content as high as 40%-51%, also placing it in the high-oil-content category. However, unlike rapeseed, peanuts are primarily processed by pure pressing rather than pre-pressing + extraction.

Why is pure pressing used for peanuts?

Peanut’s core competitive advantage lies in its flavor. The rich aroma of peanut oil is the primary reason consumers choose it. If solvent extraction is used, flavor compounds are largely lost during the refining process.

Peanut pressing process options:

Peanut oil production mainly uses the hot pressing method: peanuts are cooked at high temperature (approximately 120°C) and then fed into screw presses for pressing. The high temperature converts flavor precursors in the peanuts into aromatic compounds, giving peanut oil its rich, distinctive aroma.

Advantages of hot pressing:

High oil yield (up to 85%-90% recovery)
Rich, aromatic flavor
Suitable for large-scale continuous production

Applications of cold pressing:

Premium peanut oil markets
Retains more nutrients (vitamin E, phytosterols, etc.)
Lower oil yield, higher price point

For peanut processing, the pressed meal can still be further utilized – as a high-protein feed ingredient or for food processing applications.

V. Sunflower Seed – Oil-Type Sunflower, Pre-Pressing + Extraction

Sunflower seeds are divided into confectionery sunflower and oil-type sunflower. Confectionery sunflower is primarily consumed as a snack, while oil-type sunflower is the raw material for oil extraction.

Oil-type sunflower has an oil content as high as 45%-54%, placing it in the high-oil-content category, suitable for the pre-pressing + extraction combination process.

Key points in oil-type sunflower processing:

Dehulling is critical: Sunflower seed hulls have extremely low oil content (approximately 2%-3%) and account for 22%-40% of the total seed weight. Dehulling significantly increases the oil content of the feed material and improves equipment processing efficiency
Pre-pressing: Dehulled sunflower kernels are fed into screw presses for pre-pressing
Extraction: The pressed cake is sent to extraction equipment to recover residual oil

Sunflower oil is known as “nutritional oil” due to its high linoleic acid content, which can reach up to 70% in some varieties.

VI. Cottonseed and Rice Bran – Special Routes for By-Product Processing

Cottonseed and rice bran are by-product raw materials in oil processing, and their processing paths have certain special considerations.

Cottonseed (15%-25% oil): Cottonseed is the seed of the cotton plant, with whole seed oil content of 15%-25% and kernel oil content of 28%-39%. Cottonseed must first be dehulled (hulls account for approximately 40%-50% of the whole seed), and then either direct extraction or pre-pressing + extraction is selected based on scale. The removal of gossypol is a special requirement in cottonseed oil processing.

Rice bran (14%-24% oil): Rice bran is a by-product of rice processing, with an oil content of 14%-24%. Rice bran contains highly active lipase, which can easily cause rancidity and deterioration. Therefore, the key to rice bran processing is timely inactivation of lipase activity, followed by direct solvent extraction.

VII. How to Choose the Right Processing Method for Your Oilseed?

Three-Step Decision Framework

Step 1: Check the oil content

Oil content >30% → Consider pre-pressing + extraction or pure pressing
Oil content <30% → Consider direct solvent extraction

Step 2: Consider flavor requirements

Need to preserve distinctive flavor (peanut, sesame, olive oil) → Pressing
Neutral flavor is acceptable (soybean oil, rapeseed oil) → Extraction or combination process

Step 3: Determine equipment configuration

Pressing route: Cleaning screens → Magnetic separators → Crushers → Cookers → Screw presses → Plate-and-frame filter presses
Pre-pressing + extraction route: Pressing equipment above + Rotocel extractors + DTDC desolventizer-toasters + Solvent recovery systems
Direct extraction route: Pretreatment equipment + Extraction equipment + Refining equipment

VIII. Huatai Oilseed Processing Solutions

Henan Huatai Intelligent Equipment Group has over 38 years of experience in oil equipment manufacturing, providing complete processing solutions covering all types of oilseeds:

Pretreatment Equipment: Cleaning screens, destoners, magnetic separators, crushers, conditioners, flaking mills, cookers – customized configurations based on the pretreatment needs of different oilseeds.

Pressing Equipment: Screw presses (single units processing from a few to several tens of tons per day), hydraulic presses – suitable for pressing flavor oilseeds such as peanuts and sesame.

Extraction Equipment: Rotocel extractors, loop-type extractors, drag chain extractors, supported by solvent recovery systems and DTDC desolventizer-toasters – suitable for direct extraction of low-oil-content oilseeds such as soybeans and rice bran, as well as secondary extraction of pressed cake from rapeseed, sunflower, and other oilseeds.

Refining Equipment: Degumming tanks, alkali refining tanks, bleaching towers, deodorization towers, leaf filters – ensuring finished oils meet food safety standards.

From equipment selection and process design to installation, commissioning, and personnel training, Huatai provides complete turnkey engineering services, serving customers in over 130 countries and regions worldwide.

Final Thoughts

There is no “one-size-fits-all” equipment solution for oilseed processing. Soybean requires extraction, rapeseed needs pre-pressing + extraction, and peanut is best pressed – the right process choice depends on a deep understanding of the oil content and quality characteristics of each oilseed.

Choosing the right oil pressing equipment and process route for your oilseed type is the first step in maximizing oil yield, ensuring oil quality, and improving overall economic returns. If you are planning an oilseed processing project, please contact Huatai Group for a customized process solution and equipment configuration recommendations tailored to your raw material characteristics.