0.25%。Influences of five factors which were size of pear particles, concentration of pear particles, ratio of potato starch to CMC-Na, concentration of colloidal solution and citric acid content respectively, on ohmic heating rate for colloidal solutions with fruit granules, as well as optimization process were studied. Heating rate models was established and optimized parameters were obtained by quadratic orthogonal rotation combination design with five factors and regression analysis. Results showed that effect order of five factors on ohmic heating rate is, according to priority, colloids concentration, ratio of potato starch to CMC-Na, citric acid content, size of pear particles, and concentration of pear particles; the optimal parameter is size of pear particles of 1.0 cm, pear particles concentration of 30%, ratio of potato starch to CMC-Na of 40%, colloids concentration of 4% and citric acid content of 0.25%.