Instrumental Crispness and Crunchiness of Roasted Hazelnuts and Correlations with Sensory Assessment

Crispness and crunchiness of 15 samples of roasted hazelnuts were investigated. Force deformation curves from compression cell testing were analyzed and mechanical response variables were determined for roasted hazelnuts. Regression equations based on roasting air temperature, air velocity, and roasting time explained (R 2 _0.9 –0.98, p < 0.001) the mechanical response variables. Samples were also evaluated by a quantitative descriptive panel. Among the mechanical response variables, the first fracture point (F 1 ) observed on the force deformation curve and the slope (S 2 ) for the line between the first and second fracture points strongly correlated (inverse) with sensory crispness (R =–0.96) and crunchiness (R _–0.92), respectively.