Chitosan films incorporating jatobá fruit (Hymenaea courbaril L.) peel extract: physicochemical, morphological, thermal and bioactive properties

Biodegradable chitosan-based films containing different concentrations of jatoba fruit peel extract (0.0%, 0.04%, 0.07%, 0.1% and 0.3%) were prepared and evaluated for their antioxidant and antimicrobial activities, physicochemical, morphological and thermal properties. The extract from jatoba fruit peel was obtained and incorporated into formulations of chitosan films. The films were characterized for thickness, moisture, solubility, water vapor permeability, optical properties, color and morphology. Also, thermogravimetric analysis, differential scanning calorimetry, Fourier transform infrared spectroscopy, in vitro antioxidant activity and antimicrobial activity were performed. The addition of extract at increasing concentrations increased the in vitro antioxidant activity by about 9-60 times compared with the film without extract. Films with lower extract concentrations were more effective at inhibiting nine bacterial strains, with emphasis on Escherichia coli (95.0% inhibition), Bacillus cereus (92.5% inhibition), Bacillus subtilis (96.5% inhibition), Pseudomonas aeruginosa (94.4% inhibition), Salmonella Typhimurium (90.4% inhibition) and Salmonella Enteritidis (93.9% inhibition). Addition of the extract improved the physical properties of the film, such as moisture, solubility, WVP and luminosity. The thermal stability of the films was slightly reduced with addition of extract at increasing concentrations. Films incorporating jatoba fruit peel extract showed potential utility as 'green' bioactive, biodegradable packaging, an alternative to packaging containing petroleum derivatives.