2001 AACC Annual Meeting Charlotte, North Carolina October 14-18, 2001 Charlotte Convention Center

A two-stage wet milling procedure for corn processing has been developed. The procedure substantially decreases the total milling time and sulfur dioxide requirements when compared to the conventional wet milling process. The first stage of the process uses a water-soaking step so the germ is completely hydrated and becomes pliable enough that it does not break when the corn is coarsely ground. The second stage involves the controlled treatment of the coarsely ground corn slurry with protease. Conventional wet milling steps are then performed following the enzymatic treatment. This approach removes the diffusion barriers and allows the enzymes to penetrate inside the corn endosperm and react with the protein substrate. The current study compares the effects of the addition of commercially available enzyme preparations during conventional steeping to their comparable addition in the two-stage procedure. The results demonstrate that the application of enzymes to the normal steeping step of wet milling is not an effective means of decreasing the steeping time or sulfur dioxide usage. Only when proteases are added to the hydrated ground corn, using the modified two-stage procedure, are enzymes effective in decreasing the steeping time and sulfur dioxide requirements. The overall steeping time with the two-stage modified procedure ranges from 6 to 8 hours, representing a 67-83% reduction over the conventional process. The modified process greatly decreases and possibly eliminates the need for sulfur dioxide addition, while producing starch yields and quality equivalent to that from the conventional process.