## 1 Introduction  
According to the Environmental Protection Agency [1], VOCs are molecules with high vapor pressure and low water solubility. They are emitted as gases from certain solids or liquids distributed throughout the environment. VOCs may have short- and long-term adverse human health effects such as altered systolic blood pressure and endothelial dysfunction for acrolein, cancer risk for chloroform, styrene, trichloroethylene, and ethylbenzene, asthma for dimethyl disulfide, ethyl isobutyrate, and ethyl 2-methyl butyrate, and impaired lung function for 3-methyl-1-butanol, 2-methyl-1-butanol, isobutanol, and 1-octen-3-ol [2, 3, 4]. Large traffic volumes, vehicle engine combustion, industrial processes and exhausts, the decomposition of biological and non-biological waste, and the application of solvent varieties, pesticides, and fungicides all contribute to the release of toxic VOCs, among them benzene, toluene, ethylbenzene, and xylene. On the other hand, other groups of VOCs are produced by plants and emitted into the atmosphere, acting as long-distance modes of cellular communication in living organisms [5, 6]. Some of these VOCs do not negatively affect health, have biotechnological applications, and can be used in the food industry to fabricate active packaging combined with matrix polymers and microcapsules. In addition, such VOCs are sprayed on agricultural products to control microbial growth,toxins, pests, and fungi and are used as spoilage indicators. Depending on the species and the threat, plants can release terpen, phenylpropanoids, and fatty acids, among others [7]; in turn, these compounds also act as communication devices to warn neighboring plants of danger, stimulating the synthesis of enzymes, phytoalexins, and other defensive substances [8]. Furthermore, VOCs can improve crop yield, soil health, and plant growth and enhance plant resistance against pests and pathogens. For example, [PERSON] et al. [9] reported the antimicrobial activity of _Pseudomonas putida_ for _Pltytoophthora capsaicin_, _Pythium myriotylum_, _Rhizoctonia solani_, _C. gloesoporoides_, _Athelia rolfsii_, _Gibberella moniformis_, _Magnuordhe oryzae_, _Ralstonia pseudosolanacearum_, and _Radolphus similis_ by releasing different pyrazine derivatives, while [PERSON] et al. [10] observed that jasmonic acid induces the accumulation of \(\beta\)-cyclocitral, an apocarotenoid that triggers a defense response against _Xanthomonas oryzae_ in rice plants. The study of volatile organic compounds (VOCs) is a topic of interest for both the scientific community and society. The Web of Science reports 29,611 manuscripts relating to research carried out in countries such as China (9072 manuscripts), USA (6090 manuscripts), Italy (1747 manuscripts), South Korea (1547 manuscripts), and Germany (1493 manuscripts), amongst others. The main research fields that produce information about VOCs are the environmental sciences (29.9%), environmental and chemical engineering (24.8%), meteorology atmospheric sciences (9.8%), food science technology (3.9%), and agronomy (0.9%). Specifically, in food science technology, 75 manuscripts studied VOCs' profile as contamination indicators [11]. Fresh agricultural products are often stored for a long time after harvest. They are easily subject to attack, mainly by fungi and bacteria, which causes their spoilage and loss of quality. These microorganisms obtain energy for survival and reproduce through catabolic activities, which release volatile and non-volatile metabolites in low concentrations, making them difficult to detect. Consequently, the analysis of VOCs contributes to our understanding of microorganisms' metabolic status and serves as an indicator of microbial contamination [12]. Currently, the most popular and sophisticated techniques for detecting the VOCs of microorganisms are gas chromatography-mass spectroscopy (GC-MS), followed by electronic-nose (e-nose) sensors, proton transfer reaction mass spectrometry (PTR-MS), and biosensors [13].