Abstract:

Soy protein isolate (SPI) was used as the main raw material to prepare food packaging films by the covalent crosslinking reaction with a plasticizer and a reductant under appropriate conditions. The optimal film-forming formula and conditions were investigated using single factor method coupled to orthogonal array design. Meanwhile, SPI films obtained were analyzed for physiochemical properties and microstructure. Results showed that the optimal film formation process was achieved by using casting mold of acrylic material and drying for 2 h at 60 ℃, and the optimal film-forming formula consisted of soy protein isolate 4.0 g/100 mL, glycerin 2.0 g/100 mL, and sodium sulfite 0.1 g/100 mL. Under the above conditions, SPI films with 61.892 N tensile strength, 0.313 mg/cm2·d oxygen permeability, 2.899 mg/cm2·d carbon dioxide permeability were obtained, which are an attractive alternative to parts of plastic products for food packaging due to alleviated environment pollution and have promising development prospect as a green packaging material.

Key words: soy protein isolate, film, property, preparation