What Are the Key Steps in the Soybean Oil Extraction Process?

Soybean oil is the world’s leading vegetable oil, accounting for about 30% of total global vegetable oil production. It holds an irreplaceable role in the food industry and agricultural economy. On the consumer side, soybean oil dominates the markets for restaurant frying, food processing (accounting for 90% of fast food oil usage), and home cooking—especially in Asia and the Americas—thanks to its high smoke point, neutral flavor, and cost-effectiveness.

The production of solvent-extracted soybean oil centers on solvent extraction and involves four key processing stages: pre-treatment, extraction, desolventization, and refining.

The pre-treatment section includes equipment such as cleaning sieves, magnetic separators, crushers, softening cookers, and flaking machines. These remove impurities and transform soybeans into thin flakes by crushing and rolling, which ruptures the cell walls and improves solvent penetration. Pre-treatment steps typically include cleaning, destoning, crushing, flaking, and steaming. The goal is to remove impurities, break cell structures, and adjust moisture and temperature to maximize oil yield.

During extraction, the pre-treated soybeans are thoroughly contacted with solvent to extract the oil, forming a mixture known as miscella. Through evaporation and stripping—taking advantage of the different boiling points of oil and solvent—the solvent is vaporized and separated from the oil. The solvent vapor is then condensed and recycled. This process yields crude soybean oil.

Besides mechanical impurities, crude oil still contains phospholipids, proteins, free fatty acids, pigments, and odor-causing substances—key factors that lead to rancidity, oxidation, and spoilage, while also affecting oil color, taste, and safety. Simple filtration is insufficient to remove them; refining equipment is necessary to purify the oil and enhance quality.

Soybean oil refining involves several critical steps, commonly known as the “six-degumming” process: degumming, deacidification, dehydration, decolorization, deodorization, and dewaxing. Once tested and certified, the refined oil meets standards as solvent-extracted soybean oil.

When choosing solvent extraction equipment, selecting the right manufacturer is crucial. A strong manufacturer ensures reliable equipment and worry-free production. Interested buyers are welcome to visit and inspect Huatai Cereals and Oils Machinery for selection and consultation.