Abstract Octenylscuccinate derivatives of starch are attracting growing attention of food technologist as potential additives as emulsifying agents. The functional properties of sodium starch octenylsuccinate E 1450 depends on many structural conditions mainly to the degree of substitution of octenylsuccinate groups and degree of hydrolysis of starch macromolecules. The application of the UF membrane bioreactor to enzymatic hydrolysis could be the way of intensification of the production process, however, knowledge is needed on how it affects the functionality of the products. The aim of the work was to examine the effect of the ultrafiltration process on the surface activity of products of enzymatic hydrolysis of octenylsuccinate starch derivatives. It was found that all investigated oligosaccharides decrease interfacial tension both in air/water and toluene/water systems. The contents of filtrate, i.e., the products of higher DE values lowered the surface tension surprisingly poorly although their effectiveness of adsorption is relatively high. These hydrolysates formed very densely populated adsorption layers, but the saturation at the interface required a high bulk concentration.