A novel Mediterranean-inspired rolled food based on gelatin films containing protein–quercetin Pickering emulsions

Protein–polyphenol Pickering emulsions have gained increasing attention as multifunctional systems for the design of novel food structures. In this study, two protein–quercetin dispersions derived from musky octopus ( Eledone moschata ), previously formed at pH 2 and exhibiting different mean particle sizes, were used to prepare low-fat Pickering emulsions. The emulsions were characterised in terms of interfacial activity, droplet-size distribution, rheological behaviour, and physical stability. Selected emulsions were subsequently incorporated into fish-gelatin-based films at increasing levels, partially replacing the gelatin matrix. The incorporation of Pickering emulsions markedly modified the film properties, reducing water solubility by 15–60% and tensile strength by 50–90%, while also affecting the optical and thermal characteristics of the films. Protein-quercetin particle size played a key role in emulsion stability, while exerting a comparatively minor influence on film functionality, as opacity, colour and mechanical properties of the films were not significantly affected. Emulsion-filled films displayed enhanced antioxidant activity and maintained adequate mechanical integrity, allowing for proper handling and shaping. As an illustrative proof-of-concept example, a selected formulation was used to prepare a Mediterranean-inspired roll, showing that the developed edible film can be handled and consumed together with a food matrix. Overall, this work underscores the potential of protein–quercetin Pickering emulsions derived from undervalued marine resources as functional fillers in gelatin-based edible films, opening new avenues for the development of innovative food structures. • Protein–quercetin particle size governed EAI, ESI and thixotropy of emulsion • 50% emulsion improved mechanical performance of film for direct ingestion • FE-nsPQ50 film showed greater structural heterogeneity than FE-PQ50 • Emulsion-filled films enabled a bake-stable protein-based rolled food • Protein-based films offer an alternative to conventional polysaccharide wraps