Investigation of mechanical and physical properties of soy protein isolate - tragacanth-nanocellulose based nanocomposite film

In the past decades, environmental pollution caused by plastic packing materials, restrictions of petroleum resources and their high price attracted many researchers to produce biodegradable packaging materials. Poor mechanic properties and high water vapor permeability are two main defects of biodegradable polymers. Nanotechnology is a modification method in this case. In the current study, the effects of nanocellulose (NC) as a nano filler on the functional properties (i.e. solubility in water (SW), moisture content (MC), water vapor permeability (WVP), tensile strength (TS), elongation to break (EB), color and structural properties) of soy protein isolate-tragacanth gum (SPI-TG) were investigated. The results showed, the functional properties of SPI-TG-NC were improved. The highest yellowness index and total color difference was observed in SPI:TG (4.7:0.3), The lowest yellowness index and total color difference was observed in SPI-TG-NC (3%). The microstructure of film specimens was investigated using scanning electron microscope.