SENSITIVITY ANALYSIS FOR HYGROSTRESS CRACK FORMATION IN CYLINDRICAL FOOD DURING DRYING

A parametric analysis was performed to examine the influence of severa l factors on stress crack formation in cylindrical food during drying using a previously developed, validated simulation method. They includ ed initial food moisture (W-o), air humidity (R-h) and temperature (T- a), convective surface mass transfer coefficient (h(m)), convective su rface heat transfer coefficient (h(t)), moisture diffusivity (D-w), an d initial food diameter (d(o)). R-h influenced most strongly drying ti me for crack formation (t(cf)) followed by T-a and W-o. The other 4 pa rameters in descending order of influence were h(m), h(t), d(o) and D- w. The influence of all parameters, except W-o, was due to their influ ence on mass transfer Blot number, Bi-m, that was closely related to m oisture concentration gradient in food. The influence of W-o was due t o increased critical stress for crack formation with a reduced moistur e level.