Antioxidant films based on gelatin capsules and minimally processed beet root (Beta vulgaris L. var. Conditiva) residues

Biocomposite films were prepared by incorporating different concentrations of beet root residue powder (BRP) (2, 4, 8, and 12 g BRP/100 g water) into films based on residues of gelatin capsules (GCR) (40 g GCR/100 g water). Control films had no BRP added. A complete mechanical, physicochemical, barrier, optical, and antioxidant characterization of all films was performed. Among all the films considered, BRP12 was found to present the most adequate properties and was further investigated. SEM micrographs showed that BRP12 presented a less homogeneous surface in comparison with the control film, but they showed similar thermal stability. After 15 days of soil degradation, the films lost over 75% of weight. The films were effective on protecting sunflower oil from primary oxidation process, and BRP12 showed higher protection than control film. Therefore, this study suggests that the formulated films could act as promising antioxidant materials and contribute to environmentally friendly technologies. (C) 2015 Wiley Periodicals, Inc.