Effect of corn moisture on the properties of pet food extrudates

Corn moisture (9.5-13.5%) was significantly correlated to extrudate propert ies, even though water was added at the extruder to compensate for the diff erences in moisture. Water addition was more effective at the preconditione r than at the extruder, and longer retention preconditioner improved expans ion. Water added to the pet food formula apparently was absorbed by the oth er formula ingredients and not the corn. Controlling the specific mechanica l energy did not compensate for differences in corn moisture.