Rheological and Film Forming Properties of Banana Flour-hydrocolloids Composites

Composite films using banana flour, glycerol and hydrocolloids were prepared by casting method. The effects of hydrocolloids on rheological, mechanical and functional properties of films were investigated. The flow curves of film forming dispersions showed shear-thinning behaviour. The viscosity of CMC blended solution was higher than gelatin and control sample throughout the shear rates considered. The mechanical spectra of the film forming solution (FFS) using the frequency sweep revealed that the incorporation of hydrocolloids made the solution more elastic over viscous nature. The equilibrium moisture content, EMC of films increased with increasing relative humidity at constant temperature. The addition of CMC/gelatin to the banana flour based films increased tensile strength and reduced elongation at break and water vapour permeability of the blended films. Tensile strength and elongation percentage of biodegradable films stored at 53% RH were 11.77 MPa and 18% for CMC (40%w/w) blended banana film, 7.45MPa & 6.9% for gelatin (40%w/w) and 4.75MPa & 15.3% for control films respectively. Water vapour permeability, WVP values were 0.632, 0.621 and 0.643 g mm h⁻¹ m⁻² kPa⁻¹ for CMC(40%w/w), gelatin(40%w/w) and control films respectively.