Effect of ultraviolet radiation on morphological and physicochemical properties of sesame protein isolate based edible films

Abstract

The photo cross-linking effect of ultraviolet radiation on sesame protein isolate (SPI) based edible films was investigated. SPI films were produced by casting method and different UV light types (UV-A, UV-B and UV-C) were applied to film forming solution or to pre-formed films. The crystallinity index of films was increased according to XRD patterns. FE-SEM observation revealed that a more compact structure without pinholes and cracks was obtained by UV treatment. Moisture content, solubility and WVP were decreased and density and hydrophobicity of the films were increased after UV exposure. Mechanical properties were also improved and UV-C irradiated film forming solution exhibited the highest tensile strength (8.29 MPa) and Young's modulus (118.35 MPa). Generally, the UV radiation of films forming solution was more effective than pre-formed films and UV-C light had the highest potential in improving the properties of SPI films.