## 3 Significance of Volatile Organic Compounds in Honey
### Determination of Aroma/Flavor Profile of Honey  
Flavor/fragrance qualities of honey are very much dependent on the volatile and semi-volatile organic compounds present in both the sample matrix and headspace aroma [13,30]. The aroma profile is one of the most typical features of a food product for the evaluation of both organoleptic quality and authenticity. Unifloral honey has highly characteristic aromas, indicating the presence of VOCs derived from nectar [10,38]. Volatile substances are the main factors responsible for aroma, which in concert with other factors such as taste and physical factors contribute to the flavor [2]. In general, light-colored honey is mild in flavor and darker honey has a more pronounced flavor [19,20]. Honey aroma is very complex, involving many tens of volatile compounds and is greatly dependent upon the isolation procedure employed [21]. However, not all volatile compounds have a significant impact on honey aroma. The contribution of a given compound depends on the extent to which the concentration exceeds its odor threshold; however, the possibilities of synergistic and/or antagonistic interactions between different components should also be taken into account. Thus, even compounds present in low concentrations may contribute strongly to the honey aroma [42]. More elaborately, VOCs after being analyzed and identified by GC-MS, the concentration of each compound can be calculated from external calibration curves of standards [2]. To assess the influence of the compounds studied on overall honey aroma, odor activity values (OAV) have to be calculated by dividing the concentration of each compound by its perception threshold [4]. Of the multitude of compounds analyzed, only those displaying OAVs greater than 1 are \begin{table}
\begin{tabular}{c|c|c|c|} \hline
**Method Employed** & \begin{tabular}{c} **Honey** \\ **Type/Country** \\ \end{tabular} & **Floral Marker** & **Reference** \\ \hline \multirow{8}{*}{SPME-GC-MS} & \multirow{2}{*}{_Quillajia saponaria_ (Quillay)} & Megastigmatrienone, & \multirow{4}{*}{} \\  & & 2-\(p\)-hydroxyphenyl & \\  & (Quillay) & alcohol,\(\beta\)-pinene and linalool & \\  & & oxide. & \\  & _Escallonia_ & & \\  & _pulverulenta_ & Safranal & Montenegro \\  & (corontillo) & & _et al_. [11] \\  & _Eucryphia corifolia_ & Isophorone and cetosiophorone & \\  & (Ulmo) & & \\  & (Chile) & & \\ \hline \multirow{8}{*}{MSDE-GC-MS} & \multirow{2}{*}{Eucalyptus} & 3-caren-2-ol, p-cymene and its & \multirow{4}{*}{} \\  & & derivate alcohol. & \\ \cline{1-1}  & & & \\ \cline{1-1}  & & \
\begin{tabular}{c} Linalool oxide, lilac alcoholand \\ lilac aldehyde \\ \end{tabular} & Castro-Varquez \\ \cline{1-1}  & &
\begin{tabular}{c} Lavender \\ (Spain) \\ \end{tabular} & Nerolidol oxide & \\ \hline \end{tabular}
\end{table} 
Table 1: _Cont._deemed to contribute to honey aroma [23, 42]. Carboxylic acids are chemical compounds that have different aromas, ranging from spicy to rancid depending on the length of carbon chain. Short chain acids such as acetic acid, have spicy flavors and aromas, while butanoic acid and hexanoic acids in butter are linked to a rancid aroma [15]. Specific VOCs with different aroma descriptions are shown in Table 2.  
Conversely, an elucidation of the origin of aroma compounds should lead to a better understanding of factors causing flavor differences between honeys. In addition, to characterize the aroma of honeys from different geographical areas of origin, considerations should be made based on the variability of weather conditions, proximity of the sea and beekeeping practices [3]. [PERSON] _et al_. [3] differentiated chestnut honeys from north-east, north-west and south- east areas of Spain based on the significant differences in concentration of several volatile compounds and sensory characteristics pertaining to aroma. Concisely, many consumers seek high quality products with a clear regional identity and sensory qualities associated with the areas of origin.