Moisture and sucrose transfer in fractionated palm kernel (PKO) based films immersed in liquid solutions

Abstract

The effects of addition of sucrose, lecithin, and cellulose on unsteady state diffusivity and steady state permeability of moisture through fractionated palm kernel oil (PKO)-based films were studied under liquid-induced moisture migration at a water activity gradient of 1.0 and at a temperature of 25°C. Addition of sucrose, cellulose, and lecithin into the fat films decreased the diffusivity of moisture, but increased the permeability of moisture due to the high moisture sorption capacity of these hydrophilic components.The effect of sucrose concentration and the presence of sugar ester in the aqueous phase on the diffusivity and permeability of moisture through the fat-based film were also studied. For pure PKO films, sucrose concentration of the aqueous phase and presence of sugar ester in the aqueous phase had no effect on the diffusivity and permeability. For fat-based films containing sucrose, with increasing sucrose concentration of the aqueous phase, the diffusivity increased but the permeability decreased. Presence of sugar ester at 0.3% in the aqueous phase significantly increased permeability of the fat-based films containing sucrose.The mass transfer coefficient for sucrose leaching from the fat based films into the aqueous phase increased with sucrose content in the film. The rate of sucrose leaching out from the fat film into 0.3% sugar ester solution was higher than that into pure water. The diffusivity of sucrose in the fat film leaching out into the aqueous phase increased with sucrose content in the fat films.