Heterologous amyloid-like fibril-stabilized Pickering emulsions: a novel quality improver for clam surimi gels

In this study, pumpkin seed protein (PSP) and quinoa protein (QP) were used to prepare heterologous amyloid-like fibrils with different mixing ratios via acid-heat induction, and the resulting fibrils were further applied to stabilize Pickering emulsions. The improvement effects and regulatory mechanisms of these emulsions on the quality of clam meat paste gels were systematically investigated. The structural characteristics of the amyloid-like fibrils, the interfacial properties of the emulsions, and the physicochemical properties of the composite gels were characterized. The results showed that acid-heat treatment for 24 h effectively promoted protein conformational transition toward β-sheet-rich structures and induced the formation of amyloid-like fibrils. In addition, the PSP/QP ratio significantly affected fibril assembly behavior and emulsion interfacial properties. Among all formulations, the PQ1:4-P emulsion exhibited the most favorable overall performance, showing excellent interfacial stability and droplet organization. When incorporated into clam meat paste, the amyloid-like fibril-stabilized Pickering emulsions significantly reduced cooking loss and improved gel texture and water distribution compared with the control. Notably, PQ1:4-P produced the lowest cooking loss and the highest proportion of immobilized water, indicating that it effectively strengthened protein–water interactions and promoted the formation of a denser and more stable gel network. Moreover, the emulsion systems were able to suppress the release of undesirable fishy volatiles in clam surimi gels. These findings demonstrate that Pickering emulsions stabilized by heterologous amyloid-like fibrils can serve as effective quality improvers for clam gels, providing a novel and green strategy for the high-value utilization of plant proteins in aquatic product processing.