In-vivo nosespace analyses of VOCs were carried out using the
same settings used for the in-vitro measurements except the flux
was increased to 300 sccm. Four panellists (2 males; 2 females)
performed the analysis where their exhaled air was sampled via
short Teflon tubes (ø 6 mm, length 50 mm), which were inserted
into their noses and into a heated (95 C) nosespace air sampling
extension (NASE Ionicon Analytik GmbH, Innsbruck, Austria) apparatus
that was directly attached to the PTR-ToF-MS. Panellists were
employees from the Fondazione Edmund Mach. All panellists gave
informed consent before a short training session was carried out. A slide show was used to guide panellists through the in-vivo test.
The breathing pattern of each panelist was monitored by tracking
their breath acetone (m/z 59.049), an endogenous compound present
in exhaled air. The nosespace measurement and slideshow
began when the breathing profile was stable. Panellists were asked
to breath normally (30 s) into the nosepiece until prompted by the
slideshow to consume the entire sample using a free mastication
protocol. A hand signal for every consequent swallow was shown
until the entire sample was consumed. Upon finishing, panellists
remained seated and breathed normally for 30 s before the nosepiece
was removed. Panellists were given a one-minute break
between samples and rinsed their palates with water and unsalted
crackers. Duplicate measurements were recorded from each panellist
for all cultivars.