3.2.1. Extraction and Analysis of Volatile Organic Compounds (VOCs)

Leaves and fruits were extracted by the simultaneous distillation–extraction process using a Likens–Nickerson apparatus to obtain the volatile concentrate. The solvent of the extraction was n-pentane (3 mL) for two hours. After extraction, an aliquot (1.0 μL) of the organic phase was injected in a gas chromatography coupled with mass spectrometry (GC-MS) apparatus. The analysis was performed in GC-MS equipment (Shimadzu QP2010 ultra, Shimadzu Corporation, Tokyo, Japan) according to the following settings: Rtx-5MS (30 m × 0.25 mm × 0.25 µm film thickness), silica capillary column (Restek Corporation, Bellefonte, PA, USA); programmed temperature, 60–240 °C (3 °C/min); injector temperature, 250 °C; carrier gas, helium with linear velocity of 32 cm/s (measured at 100 °C); injection type, split (1.0 µL); split flow was adjusted to yield a 20:1 ratio; septum sweep was a constant 10 mL/min; EIMS, electron energy, 70 eV; temperature of the ion source and connection parts, 200 °C. A homologous series of n-alkanes (C8–C32, Sigma-Aldrich, Milwaukee, WI, USA) was applied to calculate the retention index (RI) [104], which were used in conjunction with the mass spectra to identify the compounds found in the libraries of Adams and FFNSC2 [105,106]. The compound percentages are based on peak integrations without standardization.