Surfactant-Free Microemulsions in Fragrance Tinctures

Tinctures are alcoholic or hydroalcoholic solutions prepared from vegetable or chemical substances. The concentration of the solute varies up to a maximum of 50%, e.g., vanilla tincture. Tinctures are very useful in the perfume industry because they contain ethanol, which can dissolve molecules such as fragrant molecules, and consequently form hydroalcoholic formulations together. Recently, we have shown that nanostructures exist in the monophasic water-ethanol-citronellol system, and it is therefore a question whether such nanostructures exist in a system where a perfume molecule of citral is present as the oil component instead of citronellol. In this study, the single-phase region was mapped conductometrically and then measured by Dynamic Light Scattering (DLS) and UV/Vis spectroscopy to determine the presence of nanostructures similar to classical microemulsions.