Can salmon oil be incorporated into edible films without ruining their texture?

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Edible composite films enriched with omega-3 fatty acids are a promising approach to developing functional foods with high nutritional value.

In this laboratory development and characterisation study, researchers made fish gelatin films containing salmon oil Pickering emulsions stabilised by marine protein–quercetin nanoparticles.

The nanoparticles produced physically stable, shear-thinning Pickering emulsions containing 10–40% (v/v) salmon oil. These emulsions were then incorporated into the gelatin matrix.

As the oil-to-gelatin ratio increased, film thickness, opacity and colour intensity increased, while water solubility decreased from 50% to 10%.

Tensile strength was reduced by 76–93% in films containing emulsions. Elongation at break—the amount the films could stretch before breaking—remained relatively high at intermediate oil contents.

FTIR and DSC analyses showed that the emulsions changed the molecular organisation of the gelatin network, weakening hydrogen-bond interactions and reducing the stability of triple-helix junction zones.

Antioxidant analyses showed greater ferric reducing capacity in emulsion-containing films, but ABTS radical scavenging activity decreased as the oil-to-gelatin ratio increased.

The researchers evaluated the films’ viscoelastic properties after short-term hydration in artificial saliva at 37 °C. This was intended to provide a preliminary indication of possible behaviour under conditions approximating the initial stages of oral processing.

Emulsion-containing films had higher viscoelastic moduli than the control film, indicating less plasticisation after hydration and suggesting improved mastication behaviour during consumption.

The results demonstrate the potential of salmon-oil-loaded Pickering emulsions for developing ingestible gelatin film matrices that combine functional performance, marine by-product valorisation and omega-3 enrichment.