Heat and Mass Transfer in Food Processing

A spherical food product of radius $R = 0.03\text{ m}$ (characteristic length for sphere $L_c = R / 3 = 0.01\text{ m}$) has thermal conductivity $k = 0.5\text{ W/(m}\cdot\text{K)}$. The surface heat transfer coefficient is $h = 5.0\text{ W/(m}^2\cdot\text{K)}$. The Biot number ($Bi$) is: