*2.1. Essential Oil Chemical Characterization*

Neroli essential oil was purchased by Gya Labs. The essential oil chemical characterization was performed on 100% pure oil. In the final product, instead, the essential oil was used in a 5% formulation.

The investigated essential oil was characterized through a Hewlett-Packard 6890 gas chromatograph equipped with a 100% dimethylpolysiloxane SE-30 capillary column (30 m length, 0.25 mm in diameter, 0.25 µm film thickness), coupled with a Hewlett Packard 5973 mass spectrometer. A programmed temperature ranging from 60 to 280 ◦C, with a rate of 16 ◦C/min was used; the analysis was performed by using helium (0.00167 cm/s linear velocity) as carrier gas.

Essential oil constituents were identified by matching the obtained spectra with those listed in the Wiley 138 mass spectral library.
