Film forming property of different soy protein isolate produced by different technologies

In order to develop edible film with high quality composed of soy protein isolate, seven different kinds of soy protein isolates were studied. The mechanical properties and water-solubility of protein films were compared. Water vapor permeability, O2-permeation and lipid peneration were studied, too. Furthermore, a vague mathematics model was used to evaluate quality of the films. In addition, the surface structures of the films were observed with scanning electron microscope. The results showed that the edible film based on GS5000, which was a common type of soy protein isolate without pellet creating, possessed the highest evaluation score. It indicated that GS5000 had better quality than the other six proteins. Meanwhile, photographs taken by scanning electron microscope proved that the film composed of GS5000 had more compact structure than the others. It concludes that GS5000 soy protein isolate was more suitable for producing edible film. This research contributes to the exploration of the edible film with high quality made of soy protein isolates.