Abstract:Pectin，sodium alginate and xanthan gum were used as the main raw materials to prepare edible polysaccharide composite film.Firstly，the rheological experiments were used to determine that the optimal concentrations of pectin and sodium alginate in the film-forming solution were 0.6% and 0.5% respectively.Then，the tensile strength of the film was taken as the evaluation index，and xanthan gum concentration，glycerol concentration and calcium chloride concentration were selected as the optimization factors.On the basis of single factor，the preparation technology of pectin-sodium alginate-xanthan gum composite film（PAX）was optimized by response surface analysis，and its comprehensive properties were determined.The results showed that when xanthan gum concentration was 0.4%，glycerol concentration was 1.8%，and calcium chloride concentration was 2%，the tensile strength of PAX reached the maximum value of 29.65 MPa.Its elongation at break and water vapor transmission rate were 19.02%，and 18.12×10-11g/（m2·s·Pa），respectively.The structure of PAX was characterized by scanning electron microscopy，Fourier transform infrared spectroscopy，and X-ray diffraction.It showed that the surface of PAX was smooth，flat，and compact，with good structural integrity and compatibility.