Volatile norisoprenoids as markers of botanical origin of Sardinian strawberry-tree (Arbutus unedo L.) honey: Characterisation of aroma compounds by dynamic headspace extraction and gas chromatography-mass spectrometry

In order to characterize and authenticate the aromatic profile of strawberry-tree (Arbutus unedo L.) honey, a dynamic headspace (DHS) extraction, followed by gas chromatography-mass spectrometry (GC-MS) analysis, was performed on 10 Sardinian strawberry-tree (Arbutus unedo L.) honey samples. A total of 28 aroma compounds were identified, but only norisoprenoid compounds such as α-isophorone, β-isophorone and 4-oxoisophorone, were recognized as specific floral origin markers of the strawberry-tree honey. The α-isophorone/β-isophorone ratio varied from 4 to 8, whereas the α-isophorone/4-oxoisophorone ratio was found to range from 11 to 20. The DHS extraction method was proposed as a valid alternative to pollen analysis for floral source detection, especially for products like strawberry-tree honey, characterized by a low pollen content.