Evaluation of the structure-bioactivity interaction in alginate-pectin films incorporated with Licania tomentosa seed extract for pear preservation.

Alginate-based films have limitations when used in isolation, including low mechanical strength, high water sensitivity, and reduced barrier properties, which can restrict their technological applicability. In this context, the present study investigated the effect of incorporating oiti seed extract on the structure and functionality of alginate-pectin biopolymer films. Small-angle X-ray scattering (SAXS) analysis revealed a concentration-dependent behavior of alginate in the extract dispersion. The profile of phenolic compounds detected in the extracts, such as vanillin (0.46 mg g-1), ferulic acid (0.49 mg g-1), and coumaric acid (0.47 mg g-1), contributed to the rearrangement in the alginate-pectin matrix, improving the mechanical and structural performance of the films. The addition of the extract caused a significant reduction in water vapor permeability (1.93-0.94 g mm m-2 d-1 kPa-1). The films incorporating the extract also exhibited significant antioxidant activity over 21 days of storage, with the 1.0% formulation showing the best balance in the retention of bioactive compounds, while higher concentrations favored biodegradability. Application of the films to minimally processed pears demonstrated that the coating method outperformed the immersion method, contributing to better visual quality, greater pH stability, and delayed surface browning. Overall, the controlled incorporation of oiti seed extract into the alginate-pectin matrix modulated the structural organization, functionality, and biodegradability of the films, highlighting their potential as a sustainable material for active food packaging.