Açaí powder-enriched biodegradable starch films: Characterization, release in food simulants and protective effect in...

Açaí is an important source of natural pigments with antioxidant capacity, such as anthocyanins. Among the various possibilities for its application is its incorporation into biodegradable films, which can act as carriers of these bioactive compounds. The objective of this study was to develop biodegradable films based on starch with different açaí powder concentrations (5 % and 15 %). The films were developed using the casting technique and evaluated in relation to barrier properties, physicochemical, biodegradability, release to food simulants, and protective effect against photodegradation of β-carotene. The addition of the natural antioxidant led to the development of films with greater color intensity and improved light barrier and mechanical properties (tensile strength and elongation). The retention of açaí powder in the polymer matrix was identified in the FTIR analysis through the intensification of some regions in relation to the control film. The cohesion and interaction between film:active compound showed an improvement in water-related properties, such as reduced permeability and water absorption. Furthermore, the active films showed sustained release of anthocyanins into the food simulant (maximum of 3.04 mg cyanidin 3-glycoside/100 g and 8.06 mg cyanidin 3-glycoside/100 g for films AP5% and AP15%, respectively) and better protection against photodegradation of the β-carotene solution (35-50 % retention when exposed to high light intensity). The rapid biodegradability, thermal stability, and stability at different pH may indicate potential application as packaging for foods susceptible to photodegradation.