| 摘要 |
In the process of producing corn-based pellets, preconditioner steam and wat er addition, as well as extruder water or screw configuration and RPM, can be manipulated to precisely control the cook level, gelatinization, and moistur e level of the meal during processing, and level of defects despite minor variation in the characteristics of the corn flour. Specifically, the preconditioner added steam-to-water ratio can be manipulated to effect cook, hydration, and partial gelatinization of the meal. In the extruder, lower extruder rotational speeds increase the residence time and increases cook. With the increase in residence time the volume of bed pack in the extruder increases. This can be reversed by adding water directly into the extruder, thereby decreasing the viscosity of the meal in the extruder. Product bulk density is changed by increasing and decreasing cook of the meal. |
