Bioactive composite films with chitosan and carotenoproteins extract from blue crab shells: Biological potential and structural, thermal, and mechanical characterization

Currently, there is an enduring tendency towards the application of biodegradable packaging to substitute synthetic plastics. Therefore, the aim of the present work was to study the effect of the addition of different concentrations of carotenoproteins extract into the blue crab chitosan-based films matrix. Structure, light barrier, mechanical, optical, antioxidant and antimicrobial properties of developed composite films were evaluated. Data displayed that the incorporation of carotenoproteins extract into the chitosan matrix engendered modifications in films ultrastructure, making them more heterogeneous and rough. With the increase of carotenoproteins concentration, the films became darker, redder, with lower transparency, mainly ascribed to carotenoproteins original color, which might aid to protect the packaged foods from alterations caused by visible and ultraviolet light. Compositing carotenoproteins with chitosan, led, similarly, to an improvement of films thermal stability until a concentration of 15% (g/100 g polymer), whereas, mechanical properties, based on tensile strength and elongation at break values, were conversely correlated with carotenoproteins added. Moreover, the addition of carotenoproteins significantly improved composite films bioactivities, suggesting that films developed in this work could be helpful in developing a novel biotechnological alternative for food and pharmaceutical industries.