Comparative analysis of Opuntia ficus-indica mucilage and gum arabic as wall materials in anthocyanin-rich raspberry pomace microencapsulation for potential food packaging applications

This study explores the valorisation of anthocyanin-rich raspberry pomace through microencapsulation using gum arabic (GA), Opuntia ficus-indica mucilage (M), and their combination (GA+M) as wall materials. The encapsulated powders were evaluated for physicochemical, functional, and antimicrobial properties to determine their suitability for food packaging applications. Mucilage-encapsulated powder exhibited the highest total phenolic content (TPC) (34.74 ± 0.94 mg/100 g DM) and superior water- and oil-holding capacities, while GA demonstrated higher solubility (87.71 %). GA+M and GA encapsulated powders demonstrated superior radical scavenging activity (54.05 ± 1.28 % and 49.00 ± 1.19 %, respectively). Colourimetric analysis revealed that GA better preserved the red hue of anthocyanins, while mucilage contributed to higher yellowness. The combination of GA+M showed enhanced antibacterial activity against Staphylococcus aureus and Candida albicans. Fourier-transform infrared spectroscopy (FTIR) confirmed the formation of stable microcapsules, with no significant cracks or oxidation observed in scanning electron microscopy (SEM) images. The study highlights the potential of Opuntia ficus-indica mucilage as a promising encapsulant for applications requiring high bioactivity and stability, while GA is suitable for formulations prioritising solubility and dispersibility. These findings support the use of raspberry pomace as a functional ingredient, aligning with waste valorisation strategies. Furthermore, the antimicrobial and antioxidant properties of these microencapsulated powders make them promising candidates for smart packaging systems, such as active films and coatings that inhibit microbial growth and monitor food freshness, thereby enhancing food safety and extending shelf life.