Wet milling is a process in which the corn continuously flows through many mechanical and chemical seperators such that it can be transformed into many finished raw materials.

The complete corn kernel is used in this process, to make products that can be categorized as sweeteners, corn oil, starches and feed products.

The Process:

  1. Steeping:
    The corn is softened to break the bonds connecting the starch, gluten, germ and fibre. It is turned into a wet mushy mixture called slurry.
  2. Milling:
    The germ, gluten and fibre are dewatered and dried by the use of filters, presses and dryers.
  3. Germ Seperation:
    The germ is spun out of the slurry. Mechanical and chemical (solvent) means are used to extract the corn oil. The remaining fibre from the germ is used as a component of animal feeds.
  4. Fibre Seperation:
    The slurry is put through a grinder to seperate the fibre from the starch and glutens. It is then filtered to remove all fibre, which is sent to become feed. The rest of the slurry continues on, now called mill starch.
  5. Starch/Gluten Seperation:
    The mill starch is centrifuged. Since the gluten and starch are different densities this is a simple method of seperation. The gluten is sent for use in feed, while the starch is used to make other products, or dried to produce Cationic starch, food grade starch or dextrines.
  6. Fermentation:
    Enzymes are added to corn starch to modify it, so that it can be fermented to produce ethanol (the drinking alcohol) which is used in both beverages and industrial applications. A by-product of this process, carbon dioxide, is sold to beverage companies where it is used to make the "fizz" in soft drinks.
  7. Syrup Conversion:
    Corn starch is liquified in water with the use of chemicals. Treatment with enzymes and other chemicals start and stop the conversion process. The process can yeild maltose, dextrose, fructose, maltodextrins, and syrups containing these sugars, including high fructose corn syrup.

Corn milling has been an important part of food processing since 1857, when starch was the only product of the process. Over the years milling has been expanded and improved over and over again. The result has been the highest quality products, and little or no waste, resulting in lower costs.


Reference: http://www.mcp.net/info/wetmill.html

Log in or registerto write something here or to contact authors.