Comprehensive Textural Characterization of Tuna Muscle to Drive Development of Plant-Based Analogs.

This study presents a comprehensive textural characterization of raw bluefin and yellowfin tuna muscle to establish reference parameters for developing plant-based analogs (PBAs) designed for raw consumption. Five instrumental texture tests were performed on samples from both groups of species (n = 64): Texture Profile Analysis, surface compression, puncture, shear, and tensile tests. The anisotropic nature of tuna muscle was evaluated by applying forces both perpendicular and parallel to connective tissue layers. Results revealed minimal textural differences between bluefin and yellowfin species, though significant anisotropy was observed across all mechanical tests depending on test methodology and attribute. Force-distance curves from puncture tests demonstrated a strong correlation (R2 > 0.80) between force peaks and the physical location of myocommata, confirming the structural importance of connective tissue layers. Raw tuna muscle exhibited low cohesiveness (15%-21%) and moderate firmness with fracturability under compression, particularly when force was applied perpendicular to connective tissue layers. These findings establish quantitative reference ranges for multiple texture parameters that are essential for developing authentic plant-based tuna alternatives, potentially addressing sustainability challenges in vulnerable tuna fisheries while meeting consumer expectations for raw fish applications.