Physicochemical, Textural, and Rheological Properties of Bigels Prepared from Large Yellow Croaker Myofibrillar Proteins and κ-Carrageenan

Abstract

Bigels combine the advantages of hydrogel and oleogel matrices, enabling simultaneous encapsulation of both hydrophilic and lipophilic compounds with good ductility and water retention. Bigels were prepared from large yellow croaker myofibrillar protein (MP)–soybean oil oleogels and κ-carrageenan hydrogels. All the bigels exhibited a milky white, solid-like self-supporting structure. Increasing the oleogel fraction enhanced droplet interactions and uniformity. Hardness peaked at 11.67 g at a 5:5 (w/w) oleogel-to-hydrogel ratio. The rheological tests revealed shear-thinning behavior across all samples, with apparent viscosity increasing progressively with oleogel content. The highest thixotropic recovery (71.07%) was observed at an oleogel-to-hydrogel ratio of 6:4 (w/w). All bigels underwent structural destabilization above 40 °C and complete liquefaction above 60 °C, indicating thermal reversibility. This study elucidates how varying the oleogel-to-hydrogel ratio modulates the physicochemical properties of bigels, providing a theoretical basis for developing high-value products from large yellow croaker.