EFFECT OF SUGARS ON THE PHYSICOCHEMICAL PROPERTIES OF W/O/W EMULSIONS

A study was made of the influence of a series of sugars (i.e., ribose, xylose, fructose, glucose, sucrose, and maltose) on the steady-flow viscosity of W/O/W emulsions in relation to the migration of water between the two aqueous phases of inside and outside of the dispersed vesicular globules permeating through the oil layer. Fluxes of sugar molecules across the oil layer were also compared with each other in the light of molecular weight and the number of equatorial-OH (e-OH) groups in a sugar molecule. Changes in the viscosity could be observed for a span of time after the preparation on either side of increase or decrease with W/O/W emulsions containing an equimolar concentration of the different sugars separately in the two aqueous phases due to the migration of water. It was found that the flux of water tends to the aqueous phase dissolving one of the sugars possessing less e-OH groups than another sugar existing in the other under an apparently isotonic condition between the two aqueous phases. The water permeation coefficient of the oil layer increased from 5.97 × 10-4 to 8.89 × 10-4 cm/s with increasing number of e-OH groups from about two (ribose) to about seven (maltose), while molar flux of sugars across the oil layer decreased with increasing number of e-OH groups in a molecule ranging from 9.83 × 10-1 to 3.99 × 10-2 μM/g of emulsion per hour. © 1991.