SUGAR DIFFUSIVITY IN AGAR GEL MILK BILAYER SYSTEMS/

To study sucrose and lactose transfer between a dairy product and a fr uit layer, this system was modelled with milk on the top of a gel cont aining 1.5% agar, 0.5% citric acid and different concentrations of suc rose (22.8, 43.3 and 61%). Average disaccharide concentrations at diff erent locations were determined for the system after different diffusi on times. Experimental data were fitted to a Fickian diffusion model w ith separate diffusivities in the milk and the agar gel phases, with c orrelation coefficient r(2) >0.98. The values of diffusivity estimated were close to those in aqueous solutions containing identical sucrose concentrations.