## 1 Introduction  
The exponential increase in the world's population (estimated to reach 9.8 billion by 2050, about 34% higher than today, according to UN estimates), combined with continuous climate changes and consequent decreasing of agricultural areas due to desertification, strengthened by the global crisis caused by COVID-19, constitutes societal and global concerns that challenge the food sector. Humanity depends heavily on plants, both as a food source and as a natural source of bioactive compounds with health-promoting properties. In the last few decades, the global interest in plant-based foods, namely fruits and vegetables, has increased due to the potential ability of bioactive compounds to scavenge free radicals (ROS and RNS) in addition to their antiproliferative, antimicrobial and anti-inflammatory activities [1, 2]. Although these properties have been mainly associated with the presence of polyphenols, glucosionolates, phytosterols, and capsaicinoids, several other secondary metabolites including some volatile metabolites (terpenoids, isothiamate, allicin, among others) also exert several bioactive functions. Several studies reported the relationship between the dietary intake of high amounts of polyphenol-rich foods and a low incidence of cancer, cardiovascular diseases and inflammation [3; 4; 5]. These metabolites have an important role in nature since they can function as an indirect plant defense against herbivores and pathogenic microorganisms, but also against extreme abiotic factors such as temperature and sun exposure, humidity, lack of nutrients, among others [6; 7; 8]. Herbivore-induced VOCs can provide signals for neighboring undamaged plants, acting as messenger compounds that transmit selective information between species to ready their inducible anti-herbivore defenses [9]. In addition, VOCs are generally involved in the attraction of pollinators, and within the complex VOC mixtures emitted by plants, pollinators only detect a part of the compounds and use a portion of them as a signal to find their resource [10]. There are three major groups of secondary metabolites originated by the biosynthesis of primary metabolism: (i) the group of terpenes derived from malonic acid or pyruvate and 3-phosphoglycerate; (ii) the group of nitrogen compounds derived from aromatic amino acids, such as tryptophan and tyrosine and aliphatic amino acids such as ornithine and lysine; and finally (iii) the group of phenolic compounds (derived from shikimic acid or malonic acid) [11; 12]. Typically, these compounds are found in fruits and vegetables in small amounts, varying from species to species, and sometimes between varieties in its chemical nature [13]. According to some studies, changes in the content of these compounds can also be influenced by environmental and agronomic conditions, the state of maturity, storage conditions and the time of exposure to UV radiation [14; 15; 16]. In general, these compounds belong to several chemical families, such as aldehydes, esters of short alkyl chains, terpenes (mainly mono and sesquiterpenes), in addition to nitrogenous and organosulfur compounds [14]. Recently, many of these compounds have become highly recognized due to their biological properties related to health benefits [17]. Terpenic and organosulfur compounds are responsible for the medicinal properties of numerous plants, such as their antihypertensive [18], anti-inflammatory [19], antibacterial [20; 21; 22] and anticancer activity [23; 24; 25]. Many of the volatile organic compounds (VOCs) and semi-volatile organic compounds (SVOCs) of fruits and vegetables are generally present in trace amounts (from several mg L\({}^{-1}\) to a few mg L\({}^{-1}\), or even less), which means that an effective extraction technique and a sensitive methodology of analysis are required for their adequate characterization [26].