The effects of temperature, pressure, and canola oil concentration on the carotenoid extraction yield were analyzed by STATGRAPHICS Plus Version 5 [28]. Analysis of variance of carotenoid yield was performed to test the main three effects (temperature, pressure and canola oil concentration) and the two-way interaction effects between them. The multiple regression equation, the estimated response surface plot, and the optimum combination of extraction factors were reported for the carotenoid yield. The effects of particle size, flow rate and moisture content of feed material on carotenoid yield were analyzed by the General Linear Model procedure of SAS Statistical Software, Version 8 [29].