The paper presents the investigation of the influence of the composition of fragrance mixtures on the competitive adsorption of these volatile amphiphilic substances at the water/air interface using tensiometry. The method is based on the measurement of the dynamic surface tension of solutions of volatile fragrances. These have pronounced surface-active properties. Furthermore, measurements of the surface tension of a water droplet suspended in the gas phase above the sample allow assessment of the evaporation of fragrances in free volume from solutions as well as from complex matrices, including micellar solutions and emulsions. In this work, model systems have been studied: aqueous solutions of ethanol, geraniol and their mixtures, and a commercial perfume product.

It is shown that the shape of the dynamic surface tension curves is sensitive both to the composition of the solution and to the change in concentration of the substances as a result of evaporation. The evaporation of ethanol from the mixed adsorption layer is significantly slower compared to its individual solution of the same concentration. This observation indicates a change in the composition of the adsorption layer at water/air interface during evaporation. The reported results may be used in praxis for controlling the flavor of products by the targeted selection of fragrance compositions.