Tensiometry as a Simple Analytical Method for Quantification of Solubility and Release of Aroma Molecules in Aqueous Media

Abstract

Dynamic tensiometry is shown to be a high-potential analytical tool in assessing physico-chemical characteristics of fragrance molecules, such as solubility limit, volatility as well as much rarely assessed interfacial activity of these amphiphilic molecules. Surface tension of aqueous solutions of selected essential oils has been measured as a function of time and fragrance concentration using maximum bubble pressure method. The effect of the temperature and saline solution on the rate of dissolution in water was assessed. Dynamic surface tension turned to be sensitive to the composition of fragrances, as demonstrated on examples of natural and synthetic mixtures. Furthermore, presented work reveals the possibility of maximum bubble pressure tensiometry method to quantify the amount of fragrance compositions in flavored salts, including the artificially aged carrier samples. Suggested here analytical approach can be used for the detection of the purity of essential oils, for the optimization of compositions and of the manufacturing processes of fragrances-containing products, as well as for the assessment of the release/evaporation of fragrances from carrier systems.

Volatile Aroma Surfactants: The Evaluation of the Adsorption–Evaporation Behavior under Dynamic and Equilibrium Conditions

“…The comparatively low surface activity of benzyl acetate is probably due to its rather good solubility in water. However, we note that this is not a general case for aroma molecules, and clarification of this dependence requires further substances to be tested.…”

“…If the diffusion transfer of the vapor through a boundary layer in the gas phase is the rate-limiting process (eq 2), it is natural to assume that the local equilibrium between the interface and the subsurface is established quickly both at the side of the aqueous solution, as well as with the interfaceadjacent volume in the gas phase. 35 This assumption implies the absence of a local barrier for the exchange of molecules between the physical interface and the subsurface. Therefore, the pressure, p s , the subsurface concentration, c sub , and the adsorbed amount per unit area, Γ, should be connected via equilibrium relationships.…”

The Influence of Divalent Cations on the Dynamic Surface Tension of Sodium Dodecylbenzenesulfonate Solutions

“…The occurrence of commercial and reliable maximum bubble pressure instruments was initially accompanied with studies that developed theoretical and experimental approaches to follow the adsorption kinetics [7][8][9][10][11][12]. Subsequently, the method has been used to investigate the adsorption behaviour of biosurfactants [13,14], gemini surfactants [15], mixed surfactant solutions [16], lung surfactants interacting with inhalable powders [17] and fragrance molecules [18].…”