Why is Abalone So Chewy? Structural Characterization and Relationship to Textural Attributes

Abstract

Abalone is a highly regarded food in many cultures. It is consumed as a luxury food, valued for its unique sensory properties, which include both flavor and texture. The aim of this research was to understand the texture of abalone and to link textural attributes to the microstructure of the muscle tissue. Two different sources, and species, of abalone—wild (Haliotis rubra) and farmed (Haliotis laevigata)—were characterized structurally using light microscopy and confocal laser scanning microscopy. The structure at different length scales of the abalone foot muscle tissues was related to perceived texture by a trained sensory panel. The results of the microscopy work showed isotropic assemblies of interwoven muscle bundles with a diameter of approximately 20–40 µm. The muscle fibers consisted of bundles of aligned muscle fibrils, 2–4 µm in diameter, that were interconnected with anisotropic collagen. During steaming, the muscle fibers were observed to separate as a result of configurational changes of the protein. The sample from wild abalone was found by the sensory panel to be the most chewy, firm and springy. The size of the collagen-rich areas was linked to the texture perception, with the toughest pieces of meat displaying the largest collagen-rich areas. The size of the muscle fiber bundles also contributed to the perceived texture, in which samples containing larger bundles were perceived as more chewy than samples with fewer fibers per bundle.