Relationship between instrumental and sensory parameters of cooked sweetpotato texture

This study compared two instrumental methods, namely uniaxial compression and texture profile analysis (TPA), with sensory evaluation in describing the textural properties of cooked sweetpotatoes. The steamed cooked samples (1.35 x 2.2 cm cylinder) of four cultivars and six selections were subjected to a trained texture profile panel for sensory ratings and the two instrumental methods for determination of the mechanical properties. Factor analysis indicated that the 15 sensory variables were grouped into 3 main factors, namely moistness-firmness (factor 1), particles (factor 2), and fiber (factor 3). Among the instrumental parameters, shear stress of compression and fracturability, hardness, and gumminess of TPA correlated highly (R = 0.73-0.95) with both the mouthfeel and mechanical-type sensory notes. These parameters of the two instrumental methods were linearly related (R-2 greater than or equal to 0.95) and could be converted from one to another with a high degree of reliability. Regression equations based on shear stress significantly explained (R-2 = 0. 71-0.91) eight of the sensory notes. These instrumental parameters can be good predictors of cooked sweetpotato texture.