Alginate based antioxidant films with yerba mate (Ilex paraguariensis St. Hil.): Characterization and kinetics of phenolic compounds release

Alginate based films added with plant extracts have been proposed as active antioxidant packaging. Therefore, it is necessary to evaluate the release process of bioactive compounds, given the complexity of these extracts. Thus, the addition of these extracts can alter the mechanical and barrier properties of the films, due to the plasticizing or compatibilizing action of some compounds. In this context, the objective of this study was to evaluate the mechanical and physicochemical properties of sodium alginate biofilms with different concentrations of yerba mate extract and investigate the release of total phenolic compounds (TPC) and chlorogenic acid (CA) in different food simulants. The addition of extract in films increased the water vapor permeability coefficient, tensile strength, and Young modulus, but did not affect elongation capacity. In the release tests, the highest release rates of TPC and CA were observed in the ethanolic solution (10 %), where the diffusional process prevailed. This behavior was associated with the polarity of the solution and compounds, and the reduced relaxing effect of the polymer chains due to crosslinking. The results indicate that the film has the potential to be used in foods that want to delay oxidative processes, since the release of TPC and CA occurred in all evaluated simulants.