Textural properties of agarose gels. II. Relationships between rheological properties and sensory texture

Descriptive analysis was used to quantify the perceived hand texture characteristics of agarose gels, and results were compared with previously developed fundamental rheological profiles to determine if relationships could be established. Four texture attributes were used to describe the gels, including ‘hand small-strain force’, ‘hand springiness’, ‘hand fracture force’, and ‘hand fracture deformation’. Gels were differentiated similarly by sensory analysis and fracture properties (p≤0.05). Hand small-strain force and ‘hand-fracture force’ terms were capable of differentiating the gels equally as well, indicating that relative gel strength was perceived similarly with non-destructive and fracture causing deformations. Surprisingly, the hand force terms correlated more highly with fracture modulus (fractures stress/fracture strain) values (r≥0.98, p≤0.001) than fracture stress values (r=0.76–0.82, p≤0.05), suggesting sensory perception of force includes a coupling of stress and strain. The definition of the term hand fracture deformation was very similar to the commonly used sensory term ‘cohesiveness’, and was highly correlated with fracture strain values (r=0.98, p≤0.001). Linear viscoelastic properties could not distinguish gels as sensitively as fracture properties. These findings clearly demonstrate fracture properties are capable of predicting sensory texture properties.