The effect of electrical processing on mass transfer in beetroot and model gels

The diffusion between solids and surrounding liquids has been studied under the influence of different electric field strengths varying between 0-1000 V m(-1), characteristic both of ohmic heating and Moderate Electric Field (MEF) processing. The rate of enhancement of mass transfer between slabs of beetroot and surrounding fluid has been studied at up to 60 degrees C, as a function of electric field strength and the orientation of the slab to the field. Enhancements in diffusion coefficient of up to a factor of 2 are seen, with decreased enhancement at higher temperature and when the electric field does not pass through the particle. Diffusion into gels has been studied and enhancement found only for alginate (an ionically set gel) and not for gelatin and egg albumin, that are thermally set gels. (C) 2012 Elsevier Ltd. All rights reserved.