*2.1. Honey Samples*

The analyses of volatiles were carried out to 25 honey samples provided directly by Greek beekeepers. Samples were produced during the 2019–2021 harvest period. The botanical origin was assessed by the beekeepers and then confirmed by melissopalynological [22], and physiochemical analysis [23,24], as previously described [25]. Floral origin was confirmed firstly according to European [26] and secondly according to the more strict Greek [27] legislation (sum of fructose and glycose not less than 60% *w*/*w*; sucrose content not more than 5% *w*/*w*; moisture content not more than 20% *w*/*w*; electrical conductivity not more than 800 (μS cm<sup>−</sup>1); diastase activity (Schade scale) not less than 8; HMF not more than 40 mg kg−1; heather pollen not less than 45%). Honey samples were kept in the dark at 4 ◦C in hermetically closed glass bottles until further analysis.
