Physical and Functional Properties of Poly (Lactic Acid)/Paprika Oleoresin Films for Food Packaging Application

Background: Paprika oleoresin is a compound extracted from paprika, with functional properties, mainly due to its fatty acid composition and carotenoid profile. The effect of these compounds on PLA composite films has not been investigated. Objective: The objective of this study is to evaluate the effect of paprika oleoresin at different concentrations on the surface color, UV barrier, mechanical barrier, water vapor barrier, hydrophobicity, paprika oleoresin release and antibacterial properties of PLA-based composite films. Methods: Functional poly(lactic acid)-based films incorporating paprika oleoresin extract (POE) at three levels (0.01%, 0.03% and 0.06%) were prepared using a solution casting method. Results: The paprika oleoresin showed an excellent compatibility with the PLA, as a uniform dispersion was observed. Moreover, the addition of POE improved properties such as elasticity (increase of 62%) and water vapor permeability (decrease of 69%). However, compared to the control film (polylactic acid), the solubility of the polylactic acid and paprika oleoresin extract films was found to be significantly increased. As the POE content increased, the color intensity of the PLA films became lighter orange-yellow. The film composed by PLA/ POE (0.06%) also presented significant bacterial inhibition for Staphylococcus aureus. In addition, the films demonstrated total carotenoid release in food-simulating liquids. Conclusion: Functional PLA/POE films can be a good alternative to replace traditional food packaging.