Effect of zein additive on perfume evaporation

Zein is known to have filmogen properties. We wanted to show if a zein film containing eugenol (eugenol as model) would retain the fragrances, slow their evaporation and therefore produce a long-lasting perception of perfume.

We added corn zein to eugenol in a hydro-alcoholic solution to form a film in vitro and at the surface of the human skin. We have studied the trapping and release of eugenol from zein film by GC/MS. Also we labelled eugenol with deuterium to image specifically its distribution in the zein film using Secondary Ion Mass Spectrometry technique (NanoSIMS 50). Finally, we applied the zein/D-eugenol formulation onto skin to image the eugenol location on and in skin by SIMS (Secondary Ion Mass Spectrometry).

We showed that eugenol evaporation from zein film can be divided in three periods. The first period (≤2 h) corresponds to the simultaneous solvent and eugenol evaporation occurring during film formation. The second period corresponds to the continuous and slow eugenol evaporation during a few hours (about 10 h) but not to its completion. The third period (at least up to 48 h) results from the trapping of eugenol in zein film. After 24 or 48 h, trapped eugenol can be released and evaporated under mechanical deformations of the film. Moreover we showed that zein addition does not favour the eugenol penetration into viable epidermis which may cause allergenic cutaneous reaction.

The zein additive is safe to use, does not impact the olfactory perception, allows a better perception of the fragrance (long-lasting effect) in a more protective way and can be used in perfume.