Abstract
Moisture diffusion in porous broccoli florets and stalks is modeled using the free volume and Maxwell-Eucken theories. These theories are based on the mobility of water and concern the variation of the effective diffusion coefficient for a wide range of temperature and moisture content during product drying. Mass and heat transport, shrinkage, and vitamin C degradation during drying of broccoli are simulated by a spatial model. The effective diffusion coefficient varies strongly with product moisture content and temperature. Vitamin C degradation is high at moisture contents around 2 kg water/kg dry matter. The influence of the size of broccoli on the drying rate is evaluated for several types of broccoli florets and stalks.
ACKNOWLEDGMENT
This work was supported by the Energy Research Program EOS (EOS LT07043) of the Dutch Ministry of Economics.