Abstract:  Orthogonal extrusion experiments with corn/cereal mixture as raw material are put forward. The extrudates characteristics are studied under two proportion treatments. By single-index evaluation, it is found that the important order are moisture content, proportion, die temperature, screw speed and die type. Furthermore, principal components method is employed on evaluation of the experimental effects, it is found that the important order are changed with die temperature, moisture content, die type, screw speed and proportion. The proper experimental conditions under the latter method are: 160℃ of dietemperature, 20% of moisture content, hole type of die, 245r/min of screw speed and proportion 1:1.

Key words: extrusion process parameters, orthogonal design, extrusion characteristics, principal component analysis.