Cornstarch is produced from corn kernels primarily through a multi-step industrial process known as wet milling, which efficiently separates the inherent starch from other kernel components.
Understanding Cornstarch Production
Cornstarch, derived from Zea mays (corn), is a widely used substance in various industries, from food to manufacturing. While corn naturally stores starch, the "making" of cornstarch for commercial use refers to the extraction and purification process.
The Wet Milling Process
The core method for producing cornstarch is wet milling. This sophisticated process is designed to break down corn kernels and separate their valuable constituents.
Key steps involved in wet milling include:
- Steeping: Corn kernels are first steeped in water, often with a small amount of sulfur dioxide, which softens them and helps loosen the gluten matrix.
- Grinding: The softened kernels are then coarsely ground, allowing for the initial separation of the germ (which contains most of the oil) from the rest of the kernel.
- Fine Grinding and Separation: The remaining slurry, primarily containing protein, fibre, and starch, undergoes further fine grinding. Centrifuges and hydrocyclones are then used to effectively separate these components based on their different densities.
Components Separated During Wet Milling
Wet milling meticulously separates the primary components of corn kernels:
- Protein: Used in animal feed or other industrial applications.
- Fibre: Often used in animal feed or as a source of dietary fiber.
- Starch: The target product for cornstarch production.
- Oil: Extracted from the germ to produce corn oil.
| Component | Primary Use/Outcome |
|---|---|
| Starch | Forms cornstarch |
| Protein | Animal feed, other |
| Fibre | Animal feed, fiber |
| Oil | Corn oil |
Finalizing the Starch
Once the starch has been effectively separated from the other components, it undergoes a crucial final step: drying. The separated starch is carefully dried to remove moisture, which transforms it into a fine, white powder known as cornstarch. This dried product is then ready for various commercial applications.
