Moisture Diffusivity in Sponge Cake as Related to Porous Structure Evaluation and Moisture Content

Abstract

ABSTRACT: Water diffusivity within sponge cake was determined at 5, 20, and 25 °C by identification from a water sorption kinetic and using a mathematical model based on Fick's 2nd law. Water diffusivity at 20 °C within sponge cake varied from 0.5 × 10 ‐10 m 2 /s to 7.5 × 10 ‐10 m 2 /s as a function of sponge cake moisture content. Influence of temperature on the concentration‐dependent diffusivity was investigated. The activation energy was found to vary with sponge cake moisture content from 84 to 128 kj/mole. Effective diffusivity variations were correlated with the changes in microstructure of the material that was observed by using environmental scanning electron microscopy. The level of porosity in the material played a dominant role in determining the effective diffusivity.