Enhancing surimi structure by lycopene-fennel extract Pickering emulsion: application in 3D printing analog beef with...

Surimi is regarded as an ideal ink for 3D food printing; however, achieving desirable texture and flavor profiles in 3D-printed meat analogs remains challenging. In this study, myofibrillar protein microgels (MMP) were extracted from surimi and used as Pickering stabilizers to fabricate lycopene- and fennel extract-loaded emulsions with varying oil volume fractions. The emulsions were then incorporated into surimi to modulate its structural, rheological, and printing properties. The Pickering emulsions with an appropriate oil volume fraction exhibited densely packed droplet networks with enhanced centrifugal and thermal stability, as well as excellent viscoelastic properties. Incorporation of these emulsions into surimi promoted the exposure of hydrophobic protein side chains and their insertion into oil droplets, thereby forming a denser and more compact protein network with improved water-holding capacity and thermal stability. This structural enhancement endowed the emulsion-enhanced surimi with suitable rheological properties, enabling smooth extrusion and high printing accuracy for intricate 3D-printed constructs. Furthermore, when fabricated into analog beef products via dual-nozzle 3D printing, the emulsion-enhanced surimi exhibited dynamic color development during cooking, driven by the Maillard reaction and lycopene Z-isomerization. Meanwhile, the emulsion droplets effectively retained the characteristic flavor of fennel extract by delaying its volatilization. Overall, this work presents a promising strategy for producing 3D-printed surimi-based analog beef with appealing color, desirable texture, and effective flavor retention, offering new insights for the development of nutritious and sustainable food products.