# Analysis of Volatiles in Food Products
###### Abstract  
The evaluation of volatiles in food is an important aspect of food production. It gives knowledge about the quality of foods and their relationship to consumers' choices. Alcohols, aldehydes, acids, esters, terpenes, pyrazines, and furans are the main chemical groups that are involved in aroma formation. They are products of food processing: thermal treatment, fermentation, storage, etc. Food aroma is a mixture of varied molecules. Because of this, the analysis of aroma composition can be challenging. The four main steps can be distinguished in the evaluation of the volatiles in the food matrix as follows: (1) isolation and concentration; (2) separation; (3) identification; and (4) sensory characterization. The most commonly used techniques to separate a fraction of volatiles from non-volatiles are solid-phase micro-(SPME) and stir bar sorptive extractions (SBSE). However, to study the active components of food aroma by gas chromatography with olfactory detector (GC-O), solvent-assisted flavor evaporation (SAFE) is used. The volatiles are mostly separated on GC systems (GC or comprehensive two-dimensional GCxGC) with the support of mass spectrometry (MS, MS/MS, ToF-MS) for chemical compound identification. Besides omics techniques, the promising part could be a study of aroma using electronic nose. Therefore, the main assumptions of volatolomics are here described. a 2021 15 September 2021 17 September 2021 17 September 2021  
Aroma (odor) is an important aspect in designing/formulating novel food products [1]. Thereby, the characterization of aroma is the main goal in many studies. Aroma characterization can give data in the area of food products' quality and their relationship to consumers' choices [2]. The aroma evaluation is often used to identify key molecules accounting for the aroma characteristics of specific food products. Most aroma molecules are volatile organic compounds. These compounds come from, e.g., the ripening of plants, the development of oils or during natural processes such as fermentation [3, 4, 5, 6], but also food contamination [7]. Moreover, the volatile compounds are likely to form during long exposure to high temperatures in the reaction of sugars with amino groups of either amino acids or peptides/proteins, which is called the Maillard reaction [8]. The Maillard-derived volatile components are responsible for the characteristic odor of bakery or roasted products, e.g., meat, nuts, and coffee. The listing of naturally-occurring aroma chemicals is very broad, ranging from acids, alcohols, aldehydes, amines, esters and ketones, heterocyclic compounds. About 10k of diverse volatile chemicals have been recognized in foodstuffs plus beverages; e.g., coffee aroma is a mix of over 1k volatiles. Lots of these compounds are frequent in several varied food products. For example, methional is determined in almost every food sample in an olfactometry study. Aldehydes were detected as quality markers of edible oils during their storage at ambient temperature [9]. Additionally, [PERSON] et al. [10] determined aldehydes and alcohols as significant volatiles in oil quality changes during storage, and the formation is negatively correlated with poly-unsaturated fatty acids amount. As was described by [PERSON] et al. [11] in their study, turkey meat is also exposedto the oxidation process and as a result, off-flavor aldehydes could be formed. According to the authors' recommendations, negative volatiles formation could be limited by the addition of vitamin E with antioxidant activity. The example of chemical components in charge of the odor of different foodstuffs is presented in Table 1. However, the contribution of the individual compound to the food aroma depends on several factors, like aroma description, adsorption to the food matrices, content in the food samples, threshold of odor, vapor pressure, chemicals interactions, and co-reaction with other volatiles [12].