A Novel Enzyme Application for Corn Wet Milling

AbstractIn corn wet milling the raw material is prepared by means of steeping. Steeping is required in order to: –obtain the valuable CSL (Corn Steep Liquor), –soften the kernel and break the cell walls. SO2 is added to the steepwater to inhibit bacterial growth. Depending on the type of corn, the steeping time in a semi‐continuous steeping system varies from 36 to 60 h, which is substantially longer than all subsequent steps in the process. The corn comprises phytic acid, which to a large extent ends up in the CSL and constitutes an undesirable component. It has now been found that the problem caused by this phenomenon can be avoided by using phytic acid degrading enzymes during steeping. It has further been found, that by adding phytic acid degrading enzymes together with plant cell wall degrading enzymes to the steep liquor, the steeping time can be reduced considerably in a conventional steeping system and even further in a two stage steeping process, whereby the second steeping stage is carried out after course grinding. Also in case conventional steeping times are applied higher starch yields and lower energy consumption may be obtained.