CELLULARITY, MECHANICAL FAILURE, AND TEXTURAL PERCEPTION OF CORN MEALEXTRUDATES

Relationships among cellular structure, fracturability, and sensory pr operties in porous, brittle extrudates were investigated. Corn-based e xtrudates intentionally processed to exhibit a range of physical struc tures were characterized in terms of cell size distribution, bulk dens ity, mechanical strength, fracturability, and sensory attributes. Thes e measurements show both mechanical strength, defined by average compr essive stress during extended deformation, and fracturability, quantif ied by fractal and Fourier analyses of stress-strain functions, increa sing with either decreasing mean cell size or increasing bulk density. Fracturability parameters or structural characteristics are furthermo re correlated with sensory scores for crunchiness, crispness, hardness and perceived density. These results indicate that cellularity strong ly influences the pattern of mechanical failure and that failure chara cteristics, such as fractal dimension or power spectrum of stress stra in functions, are reflective of sensory texture.