Abstract: In this study, the experimental method uniform design was adopted to investigate the diffusion behavior of food brilliant blue 2 in a complex gel formed from low methoxyl pectin soy hull and chitosan. The results showed that the first-order kinetic equation could describe the diffusion of the pigment in the complex gel system at swelling state. Two multiple quadratic regression equations were obtained as a reasonable characterization of apparent rate constant and diffusion coefficient as a function of various factors, respectively. The difference in the network structure could be characterized by the kinetic parameters.

Key words: pectin, chitosan, complex gel, diffusion, kinetics