Disintegrability under composting conditions of films based on gelatin, chitosan and/or sodium caseinate containing boldo-of-Chile leafs extract.

Biodegradable films based on pure gelatin (GEL100), chitosan (CH100) and sodium caseinate (SCas100), and gelatin-chitosan (GEL50:CH50) and gelatin‑sodium caseinate (GEL50:SCas50) blends, without or with boldo-of-Chile leafs extract (BoC) were studied. The solubility in water (%) of all the pure films was analyzed. Moreover, the disintegration process was evaluated throughout the mass loss (%), structural (FTIR) changes and visual analyses of films up to 5 days of composting conditions. The Boltzmann function allowed obtaining the half-maximal disintegration time (t) of all the films. Only Scas100 films exhibited complete solubility in water, compared to the other films (P < 0.05). At day 1, SCas100 + B film exhibited total mass loss, meanwhile for the other film samples this parameter varied between 47.9 ± 3.0% (CH100 + B) and 6.8 ± 1.3% (GEL100 + B) (P < 0.05). FTIR analysis showed some changes in the intensity of the typical bands of the pure or blended films. Photographs registered exhibited the complete disintegration of all films into 5 days. Finally, Boltzmann equation displayed that pure SCas100 film disintegrated in the shortest time (0.500 days), and GEL50:CH50 blended film in the longest time (1.766 days). In conclusion, the results of this work show an appropriate and complete disintegration of all studied films in composting conditions.