Water Vapor Permeability, Optical and Mechanical Properties of Salep-Based Edible Film

Abstract

This study investigates the mechanical and physical properties of salep-based edible film. Samples of edible film with varying glycerol concentrations and dry material contents were prepared and studied. The results showed that increasing the dry material content in the film solution from 1% (w/v) to 2% (w/v) decreased water vapor permeability; however, increasing the dry material content from 2% (w/v) to 3% (w/v) increased water vapor permeability. Increasing the dry material and glycerol content increased the tensile strength from 11.82 to 24.5 MPa, the percentage of film length up to the breaking point from 16.16 to 94.3% and the salep edible film thickness from 0.021 to 0.060 mm. This research demonstrated that palmate tuber salep provides the required physical and mechanical properties to give it great potential for use in edible film production. Practical Applications Salep was used as an edible film-forming material. Glycerol was found to be the most effective and stable plasticizer for the film. The physical properties of the film and also its barrier to water were investigated. Salep has potential value as a carbohydrate source that can be used to form biopolymer edible films for packaging of low and intermediate water activity food products. The edible salep films prepared in the present investigation can be applied to food packaging.