Spray-Dried Porcine Collagen Microcapsules in Tara Gum–Maltodextrin Matrices: A Sustainable Approach to By-Product Valorization for Functional and Nutraceutical Applications

Within the framework of the circular economy, this study evaluated the valorization of pig trotters as a source of porcine hydrolyzed collagen, which was microencapsulated via spray drying in maltodextrin (95%) and tara gum (5%) matrices. A 2² factorial design was applied to analyze the effect of inlet temperature (140 °C and 160 °C) and core concentration (5% and 10% w/w) on the physicochemical, techno-functional, structural, and morphological properties of the microcapsules. The hydrolyzed collagen presented a protein content of 52.03%. The microcapsules exhibited protein contents ranging from 17.82 to 29.36%, moisture between 1.58 and 4.71%, water activity ranging from 0.24 to 0.38, bulk density ranging from 0.44 to 0.49 g/mL, hygroscopicity ranging from 24.72 to 38.08%, solubility between 81.23 and 82.80%, and particle size ranging from 4.85 to 6.52 µm. SEM micrographs revealed predominantly spherical particles with indentations and agglomerates. FTIR spectra confirmed the characteristic amide bands of collagen and molecular interactions within the tara gum–maltodextrin matrix, while TGA thermograms demonstrated the thermal stability of the formulations. Core content had a greater influence than temperature on all response variables. Overall, the findings confirm that spray-drying microencapsulation is an effective strategy for producing stable, dispersible collagen-based powders with potential for functional food and nutraceutical applications, representing a sustainable pathway for valorizing animal by-products within the circular economy.