Abstract: Edible composite films were prepared using corn starch phosphate (CDP) and corn straw cellulose (CSC) as the main ingredients. The effects of CDP to CSC ratio, carboxymethyl cellulose (CMC) concentration, and glycerol (Gly) concentration on the physical properties such as tensile strength (TS), elongation at break (EAB), water vapor permeability (WVP) and transmittance (T) of the edible films were studied. Further, using the comprehensive score for the physical properties as response value, the optimum process conditions were obtained by response surface analysis as follows: CDP and CSC ratio, 8.5:1.5; CMC concentration, 0.8 g/100 mL; and Gly concentration, 1.0 g/100 mL. Under these conditions, the physical properties of edible films were the best overall with a score as high as 0.683, which was increased by 27.14% compared with that of the edible films with no added CSC, and the TS, EAB, WVP and T were 19.75 MPa, 46.89%, 1.167×10-12 g/(cm·s·Pa) and 41.86%, respectively. As observed and characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FT-IR), the surface of the CDP/CSC edible films was smooth, showing a dense structure and good compatibility of the ingredients.

Key words: edible films, corn distarch phosphate (CDP), corn straw cellulose (CSC), physical properties, structure characterization