Characterization of Films Based on Opuntia ficus-indica and Pectin

Plastic packaging is widely used in the food industry, but its persistence in the environment for centuries has driven interest in biodegradable alternatives. This study aimed to develop a biodegradable film using freeze-dried Opuntia ficus-indica cladodes in powder form (OFICP) (2 g), glycerol (30%, w/w), and varying amounts of commercial pectin: 0.5 g (F1), 1.0 g (F2), 1.5 g (F3), and 2.0 g (F4). The influence of pectin content on the films' mechanical, thermal, structural, color, and water-related properties was systematically evaluated, alongside their biodegradability in soil and simulated marine environments. Formulations containing higher amounts of pectin exhibited enhanced mechanical performance, including a 232% increase in tensile strength from F1 (2.62) to F3 (8.69), as well as improved thermal stability. Due to the hydrophilic nature of both pectin and OFICP, the films showed low contact angles (30.29-39.39°) and high moisture content (25.11-35.98%). Considering their hydrophilic nature and water-related properties, the films may be more suitable for applications involving low-moisture food products; however, further studies under different storage and environmental conditions are needed to confirm their suitability. Moreover, under experimental conditions, the films showed progressive visual disintegration in soil, with F1 and F2 exhibiting substantial disintegration by day 12 and all formulations becoming almost completely disintegrated by day 28. Thus, these findings suggest that blending OFICP with commercial pectin produces films with improved properties, with potential applications in food packaging. Furthermore, valorizing Opuntia ficus-indica byproducts provides an environmentally responsible approach to agricultural waste management while supporting the development of next-generation bio-based materials for food packaging.