Alexandra M. Machado was funded by Fundação para a Ciência e a Tecnologia (FCT)
with PhD grant SFRH/BD/117013/2016. This study was partially funded by FCT/MCTES through
national funds, under CESAM UIDB/50017/2020 + UIDP/50017/2020, CIMO UIDB/00690/2020,
CEAUL UIDB/00006/2020, MED UIDB/05183/2020, FEDER, PT2020 PACompete 2020.
The volatile profiles of 51 samples from 12 monofloral-labelled Portuguese honey types
were assessed. Honeys of bell heather, carob tree, chestnut, eucalyptus, incense, lavender, orange,
rape, raspberry, rosemary, sunflower and strawberry tree were collected from several regions from
mainland Portugal and from the Azores Islands. When available, the corresponding flower volatiles
were comparatively evaluated. Honey volatiles were isolated using two different extraction methods,
solid-phase microextraction (SPME) and hydrodistillation (HD), with HD proving to be more effective
in the number of volatiles extracted. Agglomerative cluster analysis of honey HD volatiles evidenced
two main clusters, one of which had nine sub-clusters. Components grouped by biosynthetic pathway
defined alkanes and fatty acids as dominant, namely n-nonadecane, n-heneicosane, n-tricosane and npentacosane
and palmitic, linoleic and oleic acids. Oxygen-containing monoterpenes, such as cis- and
trans-linalool oxide (furanoid), hotrienol and the apocarotenoid -isophorone, were also present in
lower amounts. Aromatic amino acid derivatives were also identified, namely benzene acetaldehyde
and 3,4,5-trimethylphenol. Fully grown classification tree analysis allowed the identification of the
most relevant volatiles for discriminating the different honey types. Twelve volatile compounds were
enough to fully discriminate eleven honey types (92%) according to the botanical origin.
