Development And Property Characterization Of Konjac Glucomannan-Chitosan-Soy Protein Isolate Edible Compound Film

Edible film is a kind of film that is made by one or more natural edible film-forming materials and has some barrier properties. Edible compound film is one composed of two or more different kinds of edible materials. It can be used in food packaging to prevent foods from spoilage. Recently, edible compound film made by two kinds of natural polymers has been studied widely. However, few reports can be seen in literature on edible compound film made from three kinds of natural materials.In this thesis, konjac glucomannan (KGM), chitosan (C) and soy protein isolate (SPI) were applied to develop a novel edible compound film; and the film-forming formula and parameters were systemically studied. Besides, water vapor permeability (WVP), tensile strength, elongation rate and transparency of the compound film were determined. The effects of film-forming conditions including the ratio of konjac glucomannan to chitosan to soy protein isolate, pH, plasticizer and its addition and drying temperature on film's properties were investigated. The effects of environmental relative humidity and stearic acid on film's water barrier ability were also studied.First, the relationship between the ratio of konjac glucomannan to chitosan to soy protein isolate and film's properties was compared. When the ratio between the film-forming materials (KGM∶C∶SPI) was 1∶1∶1, WVP of the film was the lowest while its tensile strength and elongation rate were moderate. Addition of SPI...