Gelatin-Based Films Containing Extracts of Prickly Pear (Opuntia guerrana): Characterization and Evaluation of Bioactive Properties

Gelatin has been widely used as a raw material for packaging development in the food industry. Edible films made from biopolymers such as gelatin can incorporate functional ingredients from natural sources like peel powder and fresh pulp from <i>Opuntia guerrana</i> (tuna fruit). The formulations GFP, GPP, GM, and the control GF, were developed and characterized. The physicochemical composition of PP and FP (protein, fat, ash, fiber, and carbohydrates) was evaluated. Antioxidant activity showed 98.19 ± 0.21% ABTS radical inhibition for PP. FTIR analysis showed a characteristic peak at 3294-3284 cm^-1, associated with the interaction between gelatin and hydroxyl (OH) groups from <i>Opuntia guerrana</i> phenolic compounds. The color and barrier properties of the films were affected by the addition of prickly pear peel and pulp. Mechanical properties such as Young's modulus and tensile strength showed significant differences (<i>p</i> ≤ 0.05) when pulp was added to the films. The film with PP exhibited the highest concentration of bioactive compounds (phenols, flavonoids, and betalains) and inhibited the ABTS radical 98.24 ± 0.08% and 38.50 ± 2.11% DPPH radical. All films reached biodegradation levels of approximately 90% after 15 days of incubation. The use of prickly pear residues to obtain value-added compounds can significantly modify the physicochemical and functional properties of gelatin films.