Justicia spicigera extract as an active additive in gelatin/κ-carrageenan/starch films: first evaluation in food matrices.

Abstract

This study focused on developing active films based on biopolymers (gelatin/starch/κ-carrageenan) by incorporating, for the first time, different concentrations of Justicia spicigera extract as an active agent (500, 1000, and 2000 mg∙L-1). The objective was to characterize and analyze the most important properties of these new films to determine their viability as materials for active food packaging. Microstructural analyses revealed good compatibility of the extract in the films up to the maximum concentration evaluated, while mechanical properties showed increases of 22 and 20% in tensile strength and elongation at break, respectively. Incorporating the extract also induced changes in the optical properties that, by generating progressive darkening and increased opacity, improved the films' ability to act as a barrier against UV-vis radiation. DPPH• radical scavenging activity (36.77-77.13%) and total phenolic compound content (0.27-4.47 mg GAE/g film) increased proportionally with the concentrations of the extract. Rapid degradation of the films containing the extract under natural soil conditions was confirmed. This effect attributable to microbial activity- metabolized glycosylated compounds and highlighted the films' environmental sustainability. Finally, tests with apple slices and ground beef showed that the films helped prevent undesirable changes during storage while also underscoring their potential as efficacious, active, biodegradable materials for food packaging.