What is mechanical extraction of soybean oil?

Are you considering entering the soybean oil processing industry but torn between concerns like "solvent residues in chemical extraction" and "the reliability of mechanical pressing"? Mechanical extraction of soybean oil refers to an oil extraction process that uses purely physical methods to extract oil from soybeans. Compared with chemical solvent extraction, mechanical extraction avoids issues related to chemical residues, and preserves the natural properties of the oil—making it widely used in the production of high-end edible oils.

Based on practical production scenarios, Henan Glory Company will break down the details of the mechanical soybean oil extraction process, specifying the equipment for each stage and helping you avoid unnecessary mistakes.

Process Flow and Equipment for Mechanical Extraction of Soybean Oil

I. Raw Material Pretreatment

Before soybeans are fed into the press, they must undergo the pretreatment. The purpose of this stage is to remove impurities, break down the soybeans’ cell structure, and make it easier to extract the oil during pressing. The specific steps and corresponding equipment are as follows:

1. Cleaning

Freshly harvested soybeans typically contain impurities like leaves, stones, dirt, and metal scraps, which can impair crude oil quality and wear down pressing equipment. Thus, sequential cleaning with specialized tools is necessary, such as a cleaning sieve, a destoner and a magnetic separator.

Cleaning equipment for soybean

2. Crushing

A crusher is used to break whole, clean soybeans into small particles. This step is intended to facilitate the subsequent flaking process.

3. Softening

A softening pot is used to adjust the soybeans’ moisture content to an optimal level. If soybeans are too dry, they tend to break during flaking; if they are too wet, they will stick to the equipment. This step is crucial for ensuring the quality of flaking.

4. Flaking

A double-roller flaker is used to press crushed soybeans into soybean flakes. The goal of flaking is to increase the surface area of the crushed soybeans, allowing heat to penetrate more easily during subsequent steaming and roasting, and enabling oil to be squeezed out more readily during pressing.

5. Cooking

A multi-layer cooker is used to steam and roast the soybean flakes. On one hand, this process breaks down the soybeans’ cell structure to facilitate oil extraction; on the other hand, it inactivates lipase in the soybeans, preventing post-pressing oil deterioration. After steaming and roasting, the soybean flakes should be feeded into the soybean oil extraction equipment.

Muti-layer cooker for soybean flakes

II. Pressing and Filtration

Currently, our company's soybean oil pressing production line is equipped with an oil extraction machine with an auxiliary wok, which can maintain the temperature and moisture of the soybeans at the optimal level before pressing. For efficient and stable operation, the soybean oil extraction equipment is also equipped with PLC system control. This not only ensures a high level of automation in the pressing process but also improves pressing efficiency.

The crude soybean oil obtained after pressing contains fine impurities such as fiber. It only needs to first be fed into a clarification tank, then pass through a leaf filter to separate tiny impurities, resulting in soybean oil with a rich soybean aroma.

III. Refining of Crude Soybean Oil

The soybean oil obtained after pressing and filtration is still crude oil, which cannot be directly sold as finished edible oil. It needs to undergo refining processes such as degumming, deacidification, decolorization, and deodorization. These processes make the crude oil clear and transparent, eliminate its beany flavor, and ensure its stable and safe quality.

If you want to know the soybean oil processing equipment required for your production capacity, please feel free to contact us. Henan Glory will customize a solution based on your actual needs, helping you stabilize and expand your mechanical soybean oil extraction business.