Effect of Tannic Acid Crosslinking of α-Tocopherol Microcapsules on the Functional and Mechanical Properties of Pectin-Based Films for Active Packaging

Abstract

The increasing use of conventional plastics in food packaging has intensified environmental concerns, driving the search for sustainable and biodegradable alternatives. In this context, edible films have been widely investigated as a promising strategy for the partial or total replacement of plastic packaging, particularly for the preservation of perishable foods. In addition to acting as physical barriers, these materials can contribute to maintaining food quality by delaying deterioration processes such as moisture loss and oxidation. Although the incorporation of micro- or nanoencapsulated bioactive compounds into pectin-based and other polysaccharide-based films has been extensively studied, investigations directly comparing the effect of crosslinking the microcapsules incorporated into the same film-forming matrix remain limited. In this context, the present study aimed to develop and characterize pectin-based films incorporated with vitamin E microcapsules produced using lentil protein isolate (LPI) and lactoferrin (Lf), comparing tannic acid-crosslinked and non-crosslinked systems. This approach enables a systematic evaluation of how microcapsule crosslinking influences the physicochemical, mechanical, structural, barrier, and functional properties of the films, addressing a knowledge gap concerning the role of the crosslinking state of encapsulating particles in the performance of edible films. The incorporation of 0.05%, 0.10%, and 0.20% vitamin E microcapsules resulted in films with high water solubility (85.71–92.69%) and antioxidant activity, with ABTS radical-scavenging activity reaching approximately 100% in films containing tannic acid-crosslinked microcapsules. Although the incorporation of crosslinked microcapsules reduced tensile strength, from 18.71 to 3.21 MPa, film flexibility was maintained. Overall, the results demonstrate that tannic acid crosslinking modulates the functional and mechanical properties of pectin-based films containing vitamin E microcapsules, supporting their potential application as active food packaging materials.