Oil Content Of Common Oilseeds: A Reference Guide

Oil content is the core indicator for measuring whether an oilseed is suitable for pressing and how much oil it can yield. For customers new to the oil pressing industry, understanding the oil content of different oilseeds is the first step in assessing project feasibility and estimating return on investment.

It should be noted that the oil content figures listed below are industry reference values. Actual oil yield varies depending on variety, origin, growing conditions, storage time, and pressing process. Oil content is not the same as oil yield - oil yield is typically lower than oil content, depending on the performance of the pressing equipment, operating process, and residual oil in the press cake.

#Common Oils Display

I. High Oil Content Seeds (Above 40%)

These oilseeds have high oil content and good pressing economics, making them ideal as the primary raw material for oil pressing projects.

Sesame: oil content approximately 45%–55%. Sesame has one of the highest oil contents among common oilseeds, but its seeds are small, so attention should be paid to feeding speed and pressing chamber clearance during pressing. For large-volume processing, we recommend using model ZX130 or above to avoid incomplete pressing due to excessive screw clearance.

Peanut: oil content approximately 40%–50%. Peanut is one of the oilseeds with the most mature pressing process. After dehulling, hot pressing yields high oil output with rich aroma, and residual oil can be controlled below 8%. Hot pressing with shells will result in darker oil; if a lighter oil color is desired, we recommend dehulling before pressing.

Sunflower seed: oil content approximately 30%–40% (oil-type sunflower varieties can reach 40%–54%). Oil-type sunflower has high oil content and can be pressed with shells. Cold pressing yields 2–4 percentage points less oil than hot pressing; the choice depends on your requirements for oil flavor and nutrient retention.

Palm kernel: oil content approximately 45%–50%. Palm kernel is the seed inside the palm nut shell and must be dehulled before pressing; otherwise, parts will wear out very quickly. We recommend upgrading to the next motor size above the standard model.

Copra (dried coconut): oil content approximately 60%–65%. Copra has extremely high oil content, but it must be crushed into uniform particles (about 0.3 cm) before pressing; otherwise, the feed inlet may become clogged. Copra pressing places a heavy load on the machine, so we do not recommend using 220V single-phase power.

II. Medium Oil Content Seeds (20%–40%)

These oilseeds have medium oil content and relatively high pressing feasibility, but raw material pre-treatment and process optimization need to be considered.

Cottonseed: oil content approximately 15%–25%. Cottonseed must be dehulled before pressing; pressing with shells accelerates parts wear. For cottonseed hot pressing, we recommend controlling the temperature at 80–100°C and feed moisture below 10%. After steaming and roasting, the gossypol in cottonseed cake becomes denatured, allowing it to be used as animal feed.

Rapeseed: oil content approximately 30%–45%. Rapeseed has thin shells and small seeds and does not require dehulling before pressing. Rapeseed hot pressing yields high oil output with low residual oil, making it one of the most compatible oilseeds for screw oil presses.

Safflower seed: oil content approximately 25%–35%. Safflower seed is relatively difficult to press; we recommend using model ZX105 or above, with the motor upgraded by two sizes (e.g., the standard 11kW motor for ZX105 should be upgraded to 15kW). Safflower seed usually requires hot pressing, and the finished oil may need dewaxing in cold regions.

III. Low Oil Content Seeds (Below 20%)

These oilseeds have low oil content, and the economic benefit of pressing them alone is limited. They usually require special processes or are targeted at specific markets.

Soybean: oil content approximately 10%–20%. Soybean has relatively low oil content, and cold pressing usually requires two to three pressings to achieve ideal oil output. The protein content of soybean cold-press cake can reach 39%–45%, and in some markets, the protein content of the cake is an important indicator of product value.

Corn germ: oil content approximately 8% (based on whole corn kernels). Corn germ content is low - one ton of corn kernels yields approximately 80kg of germ. For corn germ oil pressing, we recommend configuring a cooking kettle for hot pressing; a single pressing is sufficient, while cold pressing usually requires multiple pressings.

Rice bran: oil content approximately 15%–20%. Rice bran has medium oil content but high fiber content. Before pressing, it requires steaming treatment (steam temperature 100°C, material temperature 70–80°C), followed by hydraulic or screw pressing.

IV. Relationship Between Oil Content and Equipment Selection

Screw oil presses require raw material oil content above 10%. For materials with oil content below 10%, effective pressure cannot be built during pressing, and alternative extraction methods such as solvent extraction or aqueous enzymatic extraction are required.

When pressing high oil content seeds (above 40%), be careful not to feed too quickly, to avoid "chamber slippage" caused by oil separating too rapidly inside the pressing chamber. You can mix in some press cake (the residue from the first pressing) to increase friction inside the chamber and help build effective pressure.

When pressing low oil content seeds (below 20%), multiple pressings are usually required. After the first pressing, the cake still contains a significant amount of residual oil. The cake can be fed back into the press for a second or even third pressing to maximize oil extraction.

V. Residual Oil Rate - A Key Indicator of Pressing Performance

Oil content is a natural property of the raw material, while residual oil rate is the proportion of oil remaining in the press cake after pressing. Together, they determine the actual oil yield.

The industry standard for residual oil rate in screw oil presses is typically within 8%. Under normal operating conditions, residual oil can be controlled between 7%–10%; with smooth pressing, it can drop to 5%–7%, and hot pressing can usually keep it below 8%.

Simply put: Actual oil yield = Raw material oil content − Residual oil rate (after deducting moisture and other factors). For example, peanuts with 45% oil content, after hot pressing with cake residual oil controlled at 7%, yield approximately 38% actual oil extraction.

 

VI. How to Estimate Output and Return on Investment

Before launching an oil pressing project, we recommend doing a simple calculation using the raw material oil content and residual oil rate data:

Suppose you plan to process peanuts:

Raw material oil content: approximately 45%

Expected residual oil rate: approximately 7%

Actual oil yield: approximately 38%

Daily processing capacity: using ZX85 as an example, approximately 1.4–2 tons per day (24 hours)

Daily oil output: approximately 0.5–0.7 tons (estimated at 38% oil yield; varies significantly by raw material and process)

Compare this estimate with local market prices to get a preliminary assessment of the project's economic benefit. Actual output data will vary depending on raw material variety, operating process, and equipment selection. We recommend thorough communication with the equipment supplier during the project planning stage.