Development and characterization of banana flour film incorporated with montmorillonite and banana starch nanoparticles.

Banana flour film is an alternative biopolymer material but still needs improvement of its mechanical properties and water vapor permeability. Banana starch nanoparticles (BSNs), prepared using miniemulsion cross-linking, make an interesting reinforcing agent. The properties of plasticized banana flour film (PBF) were characterized incorporated with 5% (w/w) of either montmorillonite; MMT-Na+ (PBF-M) or BSN (PBF-B), including a mixture of nanoparticles at 1:1 for 5% (PBF-MB5) and 10% (PBF-MB10). PBF-MB5 provided better improvement in the film mechanical and water barrier properties compared with PBF-B. Moreover, PBF-MB5 exhibited an intercalated structure as confirmed by the shift peak of pristine MMT-Na+ from 2θ=7.3 to 3.9° and the increase in the d-spacing from 1.21 to 2.26nm in X-ray diffraction. Fourier transform-infrared spectra confirmed the intercalated structure. Therefore, the mixture of BSN and nanoclay at 5% was sufficient to reinforce the biopolymer films as a biomaterial packaging for food and pharmaceutical applications.