Corn oil is primarily extracted using a combination of mechanical and chemical processes. Here's a breakdown of how it's done:
Extraction Process of Corn Oil
The process involves two main stages, as detailed below:
1. Expeller Pressing
- Initially, corn kernels are subjected to expeller pressing. This mechanical method uses pressure to squeeze out a portion of the oil. This is the first step in the extraction process.
2. Solvent Extraction
- Following the expeller pressing, the remaining oil is extracted using solvents.
- Hexane or 2-methylpentane (isohexane) is used as the solvent. These solvents are added to the corn material, dissolving the remaining oil.
- The solvent-oil mixture is then separated from the solids.
3. Solvent Removal and Reuse
- The solvent is then evaporated from the extracted corn oil.
- The evaporated solvent is not wasted but is recovered and re-used in subsequent extraction processes, making the overall method more efficient and cost-effective.
4. Refining the Oil
- Finally, the extracted corn oil is refined using methods such as degumming and/or alkali treatment. These methods remove phosphatides (gums) from the oil, enhancing its quality and stability.
Summary of Corn Oil Extraction
Here’s a concise summary of the complete process:
| Step | Method | Purpose |
|---|---|---|
| 1. Initial Pressing | Expeller pressing | Mechanical extraction of initial oil portion |
| 2. Solvent Extraction | Using Hexane or Isohexane | Dissolves remaining oil from the corn material |
| 3. Solvent Recovery | Evaporation and collection | Recovers and reuses the solvent |
| 4. Refining | Degumming or alkali treatment | Removes phosphatides for refined oil |
This combination of mechanical pressing and chemical solvent extraction ensures that the maximum amount of oil is efficiently obtained from the corn kernels.
