Prebiotic emulsions stabilised by whey protein and kefiran

Abstract

The goal of this work has been to assess the influence of a health-promoting hydrocolloid, such as kefiran,in oil-in-water emulsions (O/W: 50/50) containing whey protein isolate (1.0% wt.). Different kefiran concentration levels (0%, 0.25%, 0.5%, 1% wt.) were studied, observing a shift from a fluid-like to asolid-like behaviour and higher viscosities when kefiran content increased. A pseudoplastic behaviour was detected for all systems studied. The observed evolution is attributed to the thickening effect exerted by kefiran, which promoted stability, in spite of observing a certain flocculation degree within the emulsion systems, demonstrated through the addition of sodium dodecyl sulphate (1% wt.). Furthermore, shortterm stability of these pseudoplastic emulsions has been verified by laser-scattering techniques. Thus, a Sauter diameter around 1 μm remained unaltered up to 7 days since preparation. The addition of kefiran in the formulation would benefit from their well-known health-promoting effects.