Learn More About Corn Steep Liquor(一)

- Dec 14, 2019-

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Is the petitioned substance formulated or manufactured by a chemical process?

Corn steep liquor is produced by steeping corn grain in water for up to 48 hours. The soluble componentsin the corn are removed because a natural lactic fermentation is taking place during steeping. Sulfur dioxide is added at rates of 0.1 to 0.2 percent and is used to cleave disulfide linkages, resulting in the degradation of the corn protein that encapsulates the starch granules. The starch is then released from the encapsulating material. The steep water containing the corn solubles are concentrated with evaporators toform corn steep liquor. Corn steep liquor is a mixture of soluble protein, amino acids, carbohydrates, organic acids (e.g., lactic acid), vitamins, and minerals. The nitrogen fraction is high in free amino acids and small peptides.In addition, there are high concentrations of amino acids glutamine, leucine, proline and aspartic acid.

Factors affecting CSL composition include corn variety, soaking time, temperature, and the presence of microorganisms.

Is the petitioned substance formulated or manufactured by a process that chemically changes the substance extracted from naturally occurring plant, animal, or mineral sources?

Corn steep liquor is derived from corn which is a naturally occurring plant. Clean corn is steeped in warm water containing small amounts of sulfur dioxide. Soaking softens the kernels and the dilute sulfurous 

acid formed when the sulfur dioxide reacts with water prevents excessive bacterial growth and loosens the gluten bonds within the corn and releases the starch. The steep water absorbs the soluble components and is later evaporated and concentrated to a solid content of about 50%.

As written above, the chemical composition of corn slurry may change, affected by soaking time, the temperature reached during lactic acid fermentation, and the microbial environment of the fermentation. These factors may also affect the quality of the final fermentation product.

Is the petitioned substance created by naturally occurring biological processes?

Corn steep liquor is not created by a naturally occurring biological process. It is created as a result of a process designed to separate corn into its four basic components, starch, germ, fiber, and protein in an aqueous medium.

Will it cause pollution during use?

Corn steep liquor, itself, not cause any environmental contamination, because the material is approximately 50% water and the soluble proteins, amino acids, carbohydrates, organic acids (e.g., lactic acid), vitamins, and minerals would be readily metabolized and utilized by micro-organisms. The sulfur dioxide added to the fermented material to cleave the disulfide linkages may need to be vented to the atmosphere.

Moreover, no pollution occurs during the production process. If pollution has to be said, then it is dust pollution, which is powdery after all. But non-combustible.