Capsicum belongs to the Solanaceae family and includes chili varieties distinguished by their size, shape, color, and pungency (Pérez-Castañeda et al., 2015). This genus is characterized by having alternate leaves, either entire or divided. Floral leaves or bracts are often joined to the floral axis, which favors the paired arrangement of leaves and the extra- axillary position of flowers and inflorescences. The reproductive structures are hermaphroditic and regular, consisting of five sepals, five petals, and five stamens. The fruit is a fleshy, hollow berry shaped like a capsule, containing seeds located in the locules.

C. annuum, C. chinense, C. pubescens, C. frutescens and C. baccatum are the five most important commercial species worldwide (Figure 1). However, the biodiversity of this genus extends to 43 species reported in tropical regions of the Americas (Coyotl-Pérez et al., 2025).

Chili fruit production generates significant economic revenue worldwide. In 2022, China allocated 759,817 ha to produce 16,837,404.78 t, yielding profits of approximately 3.16 billion USD. In Mexico, 156,718 ha were used to produce 3,113,244.27 t, generating around 1.047 billion USD. Turkey cultivated 76,398 ha and produced 3,018,775 t, with profits of 161 million USD. India produced 74,292.01 tons 8,714 ha, earning about 1.2 billion USD. In Spain, 22,260 ha were allocated to production, reaching 1,533,280 t and generating approximately 170 million USD (Odepa, 2024).

Figure 1

Phytosanitary problems can be caused by diseases associated with microorganisms or viruses, as well as insect pests. These issues can affect both yield and fruit quality, as well as the plant’s lifespan. It is estimated that 40% of the diseases affecting chili plants are of fungal origin, followed by bacterial, viral, and nematode diseases (Landa, 2012; Kulkarni et al., 2017). Chili crops require high water input and relative humidity, the latter being a favorable factor for the growth of phytopathogenic fungi. Research indicates that the main pathogens associated with chili crops are Fusarium, Pythium, and Botrytis (Schroeder et al., 2015; Romero-Arenas et al., 2022; Wang et al., 2022). However, other pathogenic microorganisms with high incidence include Phytophthora capsici, Xanthomonas campestris, Alternaria spp., Verticillium spp., Rhizoctonia spp., Leveillula taurica, Ralstonia solanacearum, Erwinia carotovora, among others (Klosterman et al., 2009; Pérez-Acevedo et al., 2017; Esyanti et al., 2020; Canseco, 2023).

In addition, several viruses have been reported that infect leaves, stems, and fruits, such as Tobamovirus tabaci (Tobacco mosaic virus-TMV), Tombusvirus lycopersici (Tomato bushy stunt virus-TBSV), Potyvirus capsimaculae (Pepper mottle virus-PepMoV), Potyvirus potato virus Y (Potato virus Y-PVY), Begomovirus capsicumhuastecoense (Pepper huasteco yellow vein virus-PHYVV), and Begomovirus capsicummusivi (Pepper golden mosaic virus-PepGMV) (Rentería-Canett et al., 2011; Landa, 2012; Velásquez- Valle et al., 2013; González-Franco et al., 2014).

Fusarium spp. Some species of this genus are considered saprophytic fungi, as they reduce chili crop yields (Mejía-Bautista et al., 2016). These microorganisms cause diseases such as soft rot and wilt or blight. These pathologies are associated with symptoms including rot of primary and secondary roots, leaf spots, chlorosis, defoliation, vascular wilt, stem and root necrosis, and reduced fruit yield (Villanueva-Arce et al., 2013; Mejía-Bautista et al., 2016; Verma et al., 2020). Fruit rot is characterized by lesions that progress rapidly until the fruit collapses with a foul odor (Figure 2A) (Pérez-Vázquez et al., 2022; Romero- Arenas et al., 2022). This disease mostly affects ripe fruits that are present in areas with high humidity, warm temperatures, and with mechanical wounds or insect damage (Chacón et al., 2021; Coyotl-Pérez et al., 2024).

Pythium spp. Species of this genus of oomycetes (false fungi) inhabit water and soil and are known as pathogens affecting crops of high economic value such as eggplant (Solanum melongena), mustard (Sinapis alba), papaya (Carica papaya), tobacco (Nicotiana tabacum), chili (Capsicum annuum), among others (Verma et al., 2020). Pythium spp. cause loss of vigor in chili seedlings and roots. Symptoms include seed, root, and fruit rot, loss of leaf turgor, and chlorotic shoot tips (Figure 2B); infected plants also show stunted growth leading to foliar wilt (Schroeder et al., 2006). The species P. ultimum and P. aphanidermatum have high incidence and cause problems in both open-field and greenhouse crops. As a result, they increase the rate of fruit softening or rot (Verma et al., 2020).

Botrytis spp. The main symptom caused by this genus is gray rot. This disease is difficult to eradicate, with Botrytis cinerea being the primary species responsible for severe postharvest losses in chili fruits (Figure 2C). Symptoms include small spots on leaves and flowers that develop into brown necrotic lesions, which may eventually cover the entire leaf and cause wilting. In addition, the stem may show elongated, sunken necrotic lesions that are brown to black in color (Wang et al., 2022).

Alternaria spp. These fungi cause small concentric leaf spots ranging from green to dark brown. Symptoms on stems appear as sunken, elongated, dark lesions that lead to wilting or dieback. On fruits, they cause lesions with dark mold sporulation that develop into sunken, concentric necrotic spots (Figure 2F) (Canseco, 2023). In addition, these fungi can damage seeds, reducing their viability, and induce severe defoliation that leaves fruits exposed to UV radiation. This, in turn, significantly reduces the quality and yield of chili fruits (Cambiagro, 2021; Canseco, 2023).

Phytophthora spp. The genus Phytophthora is classified as an oomycete that causes wilt and death in chili plants, with P. capsici being the main species involved (Esyanti et al., 2020). This pathogen causes seed rot, leaf blight, and wilting, mainly in young seedlings, as they are more susceptible (Verma et al., 2020). During the growth stage, seedlings may show root and stem rot, general wilting, stunting, and canker formation. In mature plants, infection by this pathogen primarily results in root, stem, and fruit rot, as well as wilting (Figure 2D) (Esyanti et al., 2020; Quispe-Quispe et al., 2022).

Rhizoctonia spp. Rhizoctonia is composed of a group of adelomycete fungi, classified as imperfect fungi because they lack reproductive structures such as spores. They reproduce through fragmentation of mycelium and sclerotia (Vaishnav and Meena, 2014). These microorganisms cause stem blight and root rot, leading to necrosis (Figure 2H) (Pérez- Acevedo et al., 2017). A study indicates that Rhizoctonia solani shows greater aggressiveness in C. annuum due to its higher affinity and faster infection rate. Based on this, the competitive ability of these fungi in open-field crop soils allows for greater survival and dissemination of this microorganism compared with others such as Pythium or Phytophthora (Verma et al., 2020).

Verticillium spp. This group of fungi promotes plant wilting, with the infection process beginning in the lower leaves due to factors such as excess water, high temperatures, and others. The leaves develop a pale-green coloration that progresses to necrosis surrounded by an orange-yellow halo (Figure 2G). In addition, complete plant loss occurs as a result of root rot (Klosterman et al., 2009).

Leveillula taurica. This microorganism belongs to the Ascomycetes and causes powdery mildew, producing chlorotic spots on the leaves (Figure 2I). This disease symptom is associated with powdery mildew that begins on the abaxial side of the leaf as a white to grayish powder, gradually weakening the leaf until defoliation occurs under relative humidity below 40% (Field, 2020).

Colletotrichum spp. This genus of filamentous fungi is highly aggressive in agriculture and primarily affects fruits, causing postharvest losses ranging from 10% to 80% (Ali et al., 2016; Banya et al., 2020). The disease caused by these fungi is known as anthracnose, which is favored by high humidity in ripe chili fruits (Sonawane and Shinde, 2021). The main species associated with chili crops are C. coccodes, C. dementium (leaves), C. gloeosporioides, C. capsici, C. acutatum (fruit), and C. truncatum (ripe fruits) (Than et al., 2008; Ali et al., 2016; Sonawane and Shinde, 2021). Infected fruits develop dark red sunken lesions with concentric rings containing spore clusters (Banya et al., 2020). Another characteristic is the presence of brown, black, or even salmon-colored spots where pathogen signs can be observed (Ali et al., 2016). However, symptoms vary depending on the Colletotrichum species present.

Xanthomonas campestris. Infection caused by X. campestris appears as necrotic spots surrounded by chlorotic halos. Another characteristic symptom of this bacterium is severe defoliation of chili plants. Lesions are highly prevalent on leaves and fruits, including the peduncle and calyx, and are influenced by environmental factors such as high relative humidity (>80%), high temperatures, or water stress (Figure 2E) (López-Vielma et al., 2016; Fasio et al., 2001).

Ralstonia solanacearum. Chili plants infected by R. solanacearum show a marked reduction in growth. In addition, the leaves develop chlorosis and wilt, while interveinal chlorosis and foliar epinasty occur in the stems (DGS, 2013). This bacterium is present in the soil, from where it enters through the roots and colonizes the plant’s vascular system, producing an internal abscess that blocks the transport of water and nutrients. This physiological disruption induces rapid wilting (Figure 2J) (Conesa, 2020).

Erwinia carotovora. This bacterium is known to cause soft rot in various chili species, primarily affecting fruits, stems, and roots (Figure 2K) (Kunstmann et al., 2006). The disease appears as watery, soft, foul-smelling spots, especially in previously damaged tissues. Its development is favored by warm temperatures between 28 and 35 °C, high relative humidity above 85%, and excess water conditions such as heavy rainfall or over- irrigation (López-Pérez and Sáenz, 2018).

Tobamovirus tabaco (TMV). Tobacco mosaic virus belongs to the genus Tobamovirus and can cause yield losses of up to 70% in chili plants (Velásquez-Valle et al., 2013). It is also the most prevalent, as it is transmitted through mechanical damage caused by handling seedlings during growth (Figure 2L) (González-Franco et al., 2014). Contamination of chili seeds with TMV can occur endogenously or exogenously. Exogenously contaminated seeds can result in up to 64% of seedlings carrying the virus, while endogenous contamination affects only about 15% (Velásquez-Valle et al., 2013). In addition, chili seedlings may become infected through the presence of vectors such as the grasshopper (Sphenarium purpurascens) or the leaf miner (Liriomyza trifolii), and transmission can also occur through the roots in hydroponic systems.

Tombusvirus lycopersici (TBSV). Tomato bushy stunt virus has high incidence in chili crops in northern Mexico. It infects chili and other solanaceous plants, causing stunting, excessive branching, chlorosis, and reduced fruit size (CABI, 2024). This virus is transmitted through seeds or via mechanical damage caused by infection with Olpidium spp. (González-Franco et al., 2014).

Potyvirus capsimaculae (PepMoV). Pepper mottle virus is transmitted by aphids such as Myzus persicae or Aphis gossypii, which feed on the phloem of chili plants (Velásquez- Valle et al., 2013). In the first stage of infection, symptoms include systemic necrosis, apical fruit dieback, severe stunting, and small, deformed leaflets. In the second stage, along with systemic chlorosis, chili fruits develop blisters and malformations (Bayer, 2025).

Potato virus Y (PVY). Potato virus “Y” is a Potyvirus present in chili crops in Puebla, Coahuila, Estado de México, and Nuevo León. This virus is transmitted through previously infected seeds and by aphids such as Myzus persicae, Aphis gossypii, and Macrosiphum euphorbiae (González-Franco et al., 2014). It is considered one of the most aggressive viruses, as it causes necrosis of veins, petioles, and stems, leading to plant defoliation. Other problems resulting from infection include stunted plants, flower abortion, and the production of small or deformed fruits (Velásquez-Valle et al., 2013).

Begomovirus capsicumhuastecoense (PHYVV). Pepper huasteco yellow vein virus belongs to the Begomovirus group. The whitefly (Bemisia tabaci) is a vector that simultaneously transmits PHYVV and PepGMV. Chili plants infected with this virus show mosaic-like chlorosis on the leaves, yellow-colored veins, deformed and yellowing foliage, and reduced fruit production (Velásquez-Valle et al., 2013).

Begomovirus capsicummusivi (PepGMV). Pepper golden mosaic virus has been reported in C. annuum var. glabriusculum, C. pubescens, and C. chinense (Landa, 2012). It can cause production losses of up to 43% in these species. The foliar mosaic it induces may appear as dull yellow or golden, accompanied by leaf wrinkling, deformation, and interveinal chlorosis, depending on the cultivar. PepGMV also intensifies infections by other viruses, leading to severe problems such as early senescence. Infected plants often develop distorted and yellowing leaves within 14 days, caused by severe co-infection with PHYVV (Rentería-Canett et al., 2011; Velásquez-Valle et al., 2013).

Figure 2

The control of phytopathogens in the genus Capsicum has become a major global challenge (Kim and Lee, 2022). As mentioned earlier, Capsicum plants are susceptible to various diseases caused by fungi, bacteria, and viruses. However, certain symptoms can help identify the possible causal agent, which can be further confirmed by observing its reproductive structures (Figure 3); nonetheless, pathogenicity tests are always necessary to verify the causal agent. The main methods for disease management rely on the use of synthetic fungicides, which address a wide range of diseases, are easy to apply, and relatively inexpensive. However, they significantly pollute the environment and pose serious risks to public health, causing acute intoxication, organ damage, and, in extreme cases, an increased risk of cancer (Mejía-Bautista et al., 2016).

The adverse effects of agrochemicals promote the emergence of resistant microbial species that worsen diseases, making it essential to gradually replace them with new agroecological agents (Cruz-Cerino et al., 2020; Shcherban, 2023). In this context, a promising strategy is biocontrol through the use of beneficial organisms or antagonists of phytopathogens. Another method involves the design and formulation of natural chemical fractions capable of inhibiting the growth of human pathogens and phytopathogens. This latter alternative leads to safer foods while protecting the nutritional and nutraceutical quality of a wide range of agricultural products (Abdelhamid and El-Dougdoug, 2020; Pérez-Vázquez et al., 2022). Therefore, essential oils and standardized plant extracts play an important role as natural antimicrobials that help preserve food quality and safety (Kim and Lee, 2022; Pérez-Vázquez et al., 2022; Wang et al., 2022).

Figure 3

Antagonism strategies. Antagonistic methods have revolutionized agriculture due to their ease of application and low environmental risk. These methods use microorganisms that control bacteria and fungi in chili plants. Antagonistic microorganisms synthesize secondary metabolites to inhibit the growth of phytopathogens (Mejía et al., 2016). At times, individual antagonistic microorganisms may not have sufficient activity to suppress phytopathogen growth, which has led to the use of synergistic consortia that enhance the range of inhibition.

The main antagonistic microorganisms include Trichoderma spp., Pseudomonas spp., Rhizobium spp., Bacillus subtilis, and B. amyloliquefaciens. Bacillus species directly inhibit phytopathogen growth in plants and stimulate systemic resistance in the host. They can also suppress zoospore germination and fungal germ tube elongation in host tissues. Bacillus inhibits phytopathogen growth through several mechanisms, including the production of antimicrobial compounds (oligopeptides and enzymes), competition for nutrients and space, stimulation of plant natural defenses (systemic resistance), production of siderophores that limit iron availability to pathogens, and formation of protective biofilms on roots (Valenzuela-Ruiz et al., 2024).

It has been documented that Bacillus spp. are highly effective in reducing leaf blight caused by different phytopathogenic fungi (Quispe-Quispe et al., 2022). Against fungi of the genus Fusarium, this group of bacteria produces lipopeptides that alter the hyphal cell wall, inhibiting their growth (Radzhabov and Davranov, 2010; Gond et al., 2015).

In a way, antagonists compete with phytopathogens for nutrients and space (Anjum et al., 2020). These strategies contribute to ecological sustainability; however, as soil conditions, climate, and agricultural practices change, antagonists may lose effectiveness (Jayapala et al., 2019). Although they are excellent inhibitors of phytopathogens, their action is slower compared with agrochemicals. For this reason, farmers often choose conventional agrochemicals, seeking a quick, efficient, and low-cost solution, despite the long-term damage they cause (Abdelhamid and El-Dougdoug, 2020).

In general, biological control strategies remain an excellent natural alternative for managing diseases in chili crops, improving sustainability, and reducing the excessive use of agrochemicals (Liotti et al., 2019; Anjum et al., 2020). However, it is necessary to improve their effectiveness in terms of viability and response time under changing environmental conditions. In this regard, the use of new biodegradable materials represents an area of opportunity that should be explored with particular emphasis.

Application of essential oils. Essential oils are complex mixtures of low-molecular-weight organic compounds that are harmless and possess diverse biological properties (Shahid et al., 2017; Kim and Lee, 2022). These compounds accumulate as a result of secondary metabolite biosynthesis in plants (Pandey et al., 2017). The production of secondary metabolites functions as a plant defense mechanism under stress conditions, such as disease control (Kulkarni et al., 2017; Kim and Lee, 2022; Coyotl-Pérez et al., 2024). This property can be harnessed for biotechnological purposes.

The mechanism of action of essential oils lies in their ability to alter membrane permeability, reducing bacterial viability (Hyldgaard et al., 2012). In fungi, essential oils interfere with conidial germination and affect mycelial growth due to the presence of terpenes, alcohols, phenols, and ketones. In addition, conidiophores have been reported to develop deformities as a result of changes in the electrochemical gradients of Ca²⁺, K⁺, and Mg²⁺ (Kadogliou et al., 2011; Pandey et al., 2017). Essential oils also reduce the production of ergosterol, the main sterol in the cell membrane of filamentous fungi. This weakens the lipid bilayers and disrupts osmotic balance, leading to the rupture of cellular organelles (Arora et al., 2024). Another mechanism of action is related to hydroxyl groups present in certain compounds, which can disrupt membrane lipids (Kadogliou et al., 2011). However, the mechanism of action varies depending on the phytochemical composition of the essential oil and the type of microorganism.

The use of essential oils is an agroecological alternative with broad effectiveness against various phytopathogens. Among the most commonly used are thyme (Thymus vulgaris), peppermint (Mentha piperita), turmeric (Curcuma longa), eucalyptus (Eucalyptus globulus), cinnamon (Cinnamomum verum), and clove (Syzygium aromaticum), among others (Table 1) (Ragab et al., 2012; Pérez-Vázquez et al., 2022; Arora et al., 2023; Arora et al., 2024). These oils are composed of diverse volatile compounds such as terpenes, with different relative abundances, and the major compounds are generally responsible for their antimicrobial properties (Ragab et al., 2012). Although they are harmless, essential oils may rarely cause allergic reactions in sensitive individuals (Arora et al., 2023). The application of essential oils is considered a preventive strategy, since once the plant shows severe symptoms, their activity is usually ineffective (Pérez-Vázquez et al., 2022).

Therefore, it is advisable to apply these chemical fractions at the early stages of infection to counteract disease spread. Despite their agroecological advantages, the use of essential oils is costly due to extraction methods such as steam distillation, hydrodistillation, or solvent use. In addition, their low yields and photosensitivity limit large-scale application. For this reason, new biotechnological methods are needed for large-scale production of volatiles, which could potentially be combined with new biodegradable hybrid materials to enhance and extend their biological effectiveness.

Application of natural extracts. Plant-derived extracts naturally possess antimicrobial, antioxidant, antiparasitic, and aromatic properties. For this reason, they are considered promising bioproducts for managing biotic stress factors in crops, including chili (Shafique et al., 2015; Arora et al., 2023). They also provide an agroecological pathway to support sustainable food production (Cruz-Cerino et al., 2020). In agriculture, their use enhances yield and quality of horticultural products, reduces reliance on agrochemicals, improves soil nutrition, and helps preserve environmental integrity (Godlewka et al., 2021).

Table 1

Strategy		Disease	Phytopathogen	Capsicum specie	Location	Reference
ANTAGONIST	Bacillus sp.	Anthracnose	Colletotrichum capsici UOM-02	C. annuum cv.G-4	Seed-Plántula	Jayapala et al., 2019
	Trichoderma koningii	Wilting	Fusarium oxysporum	C. annuum	Plant	Oyetunji y Salami, 2011
	Glomus mosseae
	Streptomyces griseocarneus R132 (11 cepas)	Anthracnose	Colletotrichum gloeosporioides MPU99	C. annuum cultivar Ikeda	Fruit	Liotti et al., 2019
		Wilting	Fusarium oxysporum 46.7
	Trichoderma asperellum cepa T34		Phytophthora capsici	C. annuum cv. Dulce Italiano	Plant	Segarra et al., 2013
	Trichoderma harzianum	Wilting	Fusarium oxysporum	C. annuum	In vitro	Ragab et al., 2012
	T. viride
	T. aureiviride
	Bacillus subtilis Pseudomonas fluorescens
	T. hamatum	Wilting	Fusarium oxysporum f. sp. capsici	Capsicum variedad LCA334	Rot	Anjum et al., 2020
	B. subtilis (EPCO 16 y EPC5)		Fusarium solani	C. annum cv. CO3	Plant	Sundaramoorthy et al., 2012
	Pseudomonas fluorescens
	Bacillus,		F. oxysporum f.sp. pisi	C. annuum	Plántula	Passari et al., 2018
	Staphylococcus sp.		F. oxysporum f.sp. capsici
	Pseudomonas sp.		F. proliferatum
	Sphingomonas sp.		F. udum
	Achromobacter sp.		R. solani
			C. capsici
	Bacillus sp LBF-01	Rot	Fusarium oxysporum	C. annuum	Plant	Chowdhury et al., 2020
	Bacillus subtilis Saccharomyces cerevisiae	Anthracnose Rot	Colletotrichum capsici	Capsicum spp.	Plant	Banya et al., 2020
	Bacillus spp.	Anthracnose	Phytophtora capsici	Capsicum	Plant	Quispe-Quispe et al., 2022
NATURAL EXTRACT	Murraya koenigii			C. annuum cv. Pusa Jwala	Seed	Arora et al., 2023
	Glycyrrhiza glabra
	Anethum graveolens		Fusarium oxysporum
	Polyalthia longifolia		Colletotrichum capsici
	Melia azedarach		Pythium aphanidermatum
	Cassia fistula
	Thevetia peruviana
	Eucaliptus citriodora	Wilting	Fusarium oxysporum f.sp capsici	10 variedades: Golden hot, Revival, Hot chili, Saim hot, Sky red, P6, Neelam, Sitara, Anchal, Kundri	Plant	Shafique et al., 2015
	Mosannona depressa, Parathesis cubana, Piper neesianum	Wilting	Fusarium equiseti strain FCHE	C. chinense	In vitro	Cruz-Cerino et al., 2020
			Fusarium oxysporum strain FCHJ
	Azadirachta indica Swietenia mahagoni Allium sativum	Anthracnose	Colletotrichum capsici	C. annuum	Plant	Rashid et al., 2015
	Abrus precatorius	Fruit rot	Colletotrichum capsici	C. annuum cv. K2	Plant y Fruit	Ali et al., 2016
ESSENTIAL OIL	Anethum graveolens	Wilting, Anthracnose	Fusarium oxysporum	C. annuum cv. Pusa Jwala	Seed	Arora et al., 2023
	Thymus vulgaris		Colletotrichum capsici		Leave
	Curcuma longa		Pythium aphanidermatum		Rot
	Eucalyptus globulus				Flower
	Zanthoxylum limoncello	Soft rot	Fusarium temperatum	C. pubescens	Fruit	Romero-Arenas et al., 2022
	Thymus	Anthracnose	Colletotrichum capsici	C. annuum	Seed	Arora et al., 2024
					Plant
	Mentha piperita	Rot	Fusarium sambucinum	C. pubescens	Fruit	Pérez-Vázquez et al., 2022
	Cinnamomum verum	Wilting	Fusarium oxysporum	C. annuum	In vitro	Ragab et al., 2012
	Syzygium aromaticum
	Thymus vulgaris
	Citrus x limon
	Mentha x piperita
	Brassica juncea
	Cymbopogon citratus	Anthracnose	Phytophthora capsici	C. annuum	Fruit	Ali et al., 2015
	Piper auritum Kunth		Fusarium oxysporum	C. chinense	In vitro	Chacón et al., 2021
			Fusarium equiseti

One of the main advantages of using plant extracts is that they can be as effective, or even more effective, than synthetic products for controlling the onset of diseases, while having minimal impact on the environment and on the health of both farmers and consumers (Cruz-Cerino et al., 2020; Kim and Lee, 2022). A major challenge for achieving reproducibility in the use of plant extracts is standardization, since obtaining bioactive extracts from wild material raises several issues, including variation in secondary metabolites within the extract and the risk of violating conservation regulations for wild species.

The terms “natural extract” and “essential oil” are often confused because both are derived from plants. However, they differ in their extraction methods and chemical composition. Natural extracts are obtained through solvent extraction, whereas essential oils are mainly obtained by steam distillation. Their composition also differs: extracts contain a broad spectrum of chemical compounds, while essential oils are composed primarily of terpenes and volatile compounds.