Evaluation of Physical, Mechanical and Antibacterial Properties of Pinto Bean Starch-Polyvinyl Alcohol Biodegradable Films Reinforced with Cinnamon Essential Oil

Polymers (Basel). 2021 Aug 18;13(16):2778. doi: 10.3390/polym13162778.

Abstract

In the present study, various blended films from polyvinyl alcohol (PVA) and pinto bean starch (PBS) were prepared and the selected film was used to fabricate an antimicrobial packaging film. Different essential oils (EOs) were also exposed to minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) tests to find the most efficient EO against a range of microorganisms. From the primary studies, the PVA:PBS (80:20) and cinnamon essential oil (CEO) were chosen. Afterward, the blend composite film reinforced by 1, 2, and 3% CEO and several, physical, mechanical, structural, and antimicrobial attributes were scrutinized. The results showed a significant modification of the barrier and mechanical properties of the selected blended films as a result of CEO addition. Scanning electron micrographs confirmed the incorporation and distribution of CEO within the film matrix. The X-ray diffraction (XRD) patterns and Fourier transform infrared (FTIR) spectra indicated the interaction of CEO and the PVA-PBS composite. The antibacterial of the tested bacteria showed a significant increase by increasing the CEO concentration within the control film. CEO-loaded films were more effective in controlling Gram-positive bacteria compared to Gram-negative bacteria. It can be concluded that PVA-PBS-CEO films are promising candidates to produce biodegradable functional films for food and biomedical applications.

Keywords: antimicrobial properties; essential oils; packaging film; pinto bean starch; polyvinyl alcohol.