The aim of this work was to develop edible films derived from gelatin and beef broth and to analyze the physical properties of the output products. The presented research is important from the point of view of searching for food packaging solutions that may replace traditionally used plastic packaging. This study's conceptual framework is in line with the trend of sustainable development and zero waste. This study was conducted to develop a recipe for edible films derived from beef gelatin with gelatin concentrations at 4%, 8%, and 12% enriched with additions of beef broth in amounts of 25, 50, 75, and 100%. Selected physical properties of the output edible films were examined in terms of thickness, swelling in water, opacity, water content, water solubility, structure, and mechanical properties. The conducted research made it plausible to conclude that the addition of broth has a positive effect on the extensibility of the edible films and the other physical properties under consideration, especially on decreasing the film thickness, which was found to vary between 50.2 and 191.6 µm. When gelatin and broth were added at low concentrations, the tensile strength of the films increased, and subsequently decreased; however, an opposite effect was observed for elongation at break. The increased broth concentration caused the film opacity to increase from 0.39 to 4.54 A/mm and from 0.18 to 1.04 A/mm with gelatin concentrations of 4% and 12%, respectively. The water solubility of the gelatin films decreased as a result of the broth addition. However, it was noticed that increasing the content of broth caused the water solubility to increase in the tested films. The mere presence of broth in the gelatin films changed the microstructure of the films and also made them thinner.
Keywords: beef broth; edible films; gelatin; side products.