# Analysis of Volatiles in Food Products
###### Abstract
Certain volatile compounds do not contribute to food aroma, whereas others define the flavor of food products; for instance, benzaldehyde is a characteristic compound in the aroma of almonds, and citral is a defining aroma of lemons [13]. However, in most cases, the aroma depends on the contribution of a mix of volatile components from various chemical classes. The complexity of food aroma makes the preparation of the sample an essential stage prior to the final investigation. In a matter of technology, the certain detection and categorization of aroma components is a demanding part. Moreover, volatile molecules can naturally interact with the food matrix and also with other food components. The interactions can be classified into three groups. The first is synergism, the second compensation and the third one is masking. Following the definitions created by [PERSON] and [PERSON] [12]: \"_Synergism_ is defined as the interaction when two or more distinct substances produce a mutual scient which is stronger than those of individual components. _Compensation_ is the case when one component counteracts another constituent. _Masking_ is the combination of one pleasant odor with an unpleasant.\" Therefore, as was mentioned before the challenging part, the proper preparation of food samples. Generally, the preparation of food samples prior to analysis could be divided into three main phases. These phases are named as follows: sample pretreatment, preparation and analysis by adequate apparatus [42; 43]. \begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Family Group** & **Compounds Example** & **Aroma Description** & **Examples of Food Sample** & **References** \\ \hline
**alcohols** & hexanol & bitter, floral & watermelon & [14; 15] \\ \hline  & mycrene & earthy, fruity, and clove-like & lemongrass, clove, bay leaves, & [15] \\
**terpenes** & \(\alpha\)- and \(\beta\)-pinene & woody, green, pine-like 1 & basil and thyme & [16; 17] \\  & limonene & citrus-like & black pepper & [16; 18; 19; 20; 21] \\  & linaolol & floral & gistachio, nuttape, gin & [18; 20; 21] \\ \hline  & hexanol & freshly cut grass & salmon, chestnut & [22; 23; 24] \\  & octanal & fruity & pearnut, walnut, lamb meat & [25; 26; 27] \\ \hline  & ethyl octanoate & sweet, fruity, brandy-, apple-, & fermented and dried fish; wine; & [28] \\
**esters** & ethyl hexanoate & apricot- and banana-like & Xiaoqu Liquor & [29; 30] \\  & ethyl hexanoate & floral, fruity, pineapple-like & alcoholic beverages & [30; 31] \\ \hline  & furan & sweet, woody, almond-like, & coffee & [32] \\  & furfural & baked bread & cookies, bread & [33; 34; 35] \\ \hline  & 2,5-dimethyl-4- & & & \\  & hydroxy-3(2H)- & fruity, strawberry-like & kiwifruit, strawberry & [36; 37] \\  & furanone & (furaneol) & & \\ \hline  & 2,5-dimethylpyrazine & roast, coffee-line, peanut-like 2 & peanut, cookies & [3; 26; 33] \\
**pyrazines** & ethylpyrazine & nutty, buttery, peanut & cookies, roasted beef & \\  & methylpyrazine & nutty, cocoa, roasted meat & cocoa, cookies & [33; 38] \\ \hline
**acids** & acetic acid & acidic 1 & hazelnut; bread sourdough & [35; 39] \\ \hline \hline  & & & & \\ \end{tabular}
\end{table} 
Table 1: The most frequent volatile compounds from different family groups, their characteristic aroma and their occurrence in food products. The review presents the key concerns and examples of sample pretreatment and preparation that are obligatory in the analysis of food volatiles. The gathered information covers also aspects of methods of identification in the new branch of analysis called volatolomics [44; 45; 46]. The un- and targeted analysis are very frequent in the determination of volatile metabolome [47; 48]. [PERSON] et al. [49] studied the volatile profile of cocoa beans to determine the best conditions of their fermentation and drying process, whereas [PERSON] et al. [50] and [PERSON] et al. [51] examined the fingerprint of volatile compounds of cocoa according to their different geographical origin.