Characterization of firmness in fermented sea bass (Lateolabrax japonicas) by multidimensional integration strategies: Insights from proteomic and microstructural analyses

Fermented sea bass, recognized for its firmness and chewy texture, provides a distinct sensory experience.This study investigated the texture and microstructural properties of fermented sea bass during fermentation. Proteomics analysis identified the key proteins involved in firmness development, revealing the molecular mechanisms behind these changes. Water migration and myofibril thickening were significant contributors to the increased firmness, hardness, and chewiness. Label-free proteomics revealed 881 proteins, with 426 were differentially expressed, leading to the identification of 155 key protein biomarkers linked to texture. Structural proteins such as myosin light chain and actin correlated positively with hardness, chewiness, and adhesiveness. Fermentation also increased phosphorylation, enhancing protein degradation and texture attributes. Signaling pathways such as PI3k-AkT, HIF-1, and calcium ion signaling pathways were implicated in metabolism and myosin assembly, fortifying muscle tissue firmness. This study provided critical insights into the quality control and production optimization in the fermented sea bass industry.