How does prepressing help extract oil from seeds with high oil content?

Prepressing is a critical step in the processing of oilseeds with high oil content, such as those richer in oil than soybeans. This method involves using a screw press to remove a significant portion of the oil before the material undergoes solvent extraction.1

Prepressing helps extract oil through two primary mechanisms:

• Bulk Oil Removal: By mechanically squeezing out a large proportion of the oil initially, the process makes the subsequent solvent extraction more efficient and economical.1
• Cellular Disruption: The high-pressure environment of the screw press ruptures the cellular structures of the oil-bearing material. This structural breakdown makes the remaining residual oil more accessible, allowing solvents to penetrate the meal more effectively and recover nearly all of the remaining oil—often reducing residual oil content to less than 1 percent.1

This combination of mechanical prepressing followed by solvent extraction allows for a more complete recovery of oil than would be possible through mechanical pressing alone.21