Os óleos essentcial oils (EOs) areis (OE) são produtos natural products obtained from different parts ofis obtidos de diferentes partes das plants (roots, bark, leaves, and flowers). They are hydrophobic liquidas (raízes, cascas, folhas e flores). São líquidos hidrofóbicos containingendo misturas complex mixtures of aromatic compoundas de compostos aromáticos derived from the biosynthesis of secondaryados da biossíntese de metaboliteólitos secundários, serving as a defense againstdo como defesa contra agentes external agents. Theos. Os components of EOs belong to difes dos OE pertencem a diferentes classes ofde compounds, such as stos, como monoterpenes andos e sesquiterpenes, alcohols, esteros, álcoois, ésteres, aldehydes, ketones, and phenols, all of which possess variouídos, cetonas e fenóis, todos possuindo várias propriedades biologicalógicas [1 properties] ^[1]. CAturrently, EOs have been widely used in the foodalmente, os OEs têm sido amplamente utilizados nas indústrias alimentícia, cosmetics, pharmaceutical, and chemical industries, as well as inética, farmacêutica e química, bem como na perfumeryaria [ 2 ^[2]]. One

Um dof the highly valueds óleos essential oils (EOs) by the food industry is cinnamonciais (OE) muito valorizados pela indústria alimentícia é o óleo essential oilcial de canela (CEO) from thedo gênero Cinnamomum genus, which can beque pode ser extracted from the root, bark, or leaves, each ído da raiz, da casca ou das folhas, cada um apresenting distinct chemical compositionando composições químicas distintas. Notably, cinnamon barkvelmente, o óleo essential oilcial de casca de canela (EO) is rich in cinné rico em cinamaldehyde, leaf EO containsído, o OE da folha contém eugenol, and root EO contains camphor e o OE da raiz contém cânfora [ 3 ^[3]]. CEOFoi has been shown to possessdemonstrado que o CEO possui antimicrobialno [ 4 , 5 ^[4][5]], antifuúngalico [ 6 , 7 , 8 ^[6][7][8]], anti-inflammatoryatório [ 9 ^[9][10], and10 ] e antioxidante [ ^[11][12]11 , 12] acAtivitidades. Consequently, CEO finds applications in culinary emente, o CEO encontra aplicações em preparations due to its sweet and spicy aroma and flavor. It is commonly used in meat seasoning, baked goods, and pastries as anções culinárias devido ao seu aroma e sabor doce e picante. É comumente usado em temperos de carne, assados ​​​​e doces como conservante alternative preservativeo [ ^[13],13 and] in chewing gum as a flavoringe em gomas de mascar como agente ^[14]. Caromatinnzamon nte [ 14 ].

A can be found on the market in two main speciela pode ser encontrada no mercado em duas espécies principais: Cinnamomum verum (tcanela verue cinnamon ordadeira ou Ccaneylon cinnamla do Ceilãon ) ande Cinnamomum cassia (syin. Cinnamomum aAromaticum) ., falsea cinnamon). Due to its high market value, sweeter and milder flavor, and higher amounts of phenolic and aromatic compounds such as anela). Devido ao seu alto valor de mercado, sabor mais doce e suave e maiores quantidades de compostos fenólicos e aromáticos, como eugenol and cinne cinamaldehyde, true cinnamon is more challenging to obtainído, a canela verdadeira é mais difícil de obter em compared to false cinnamon. False cinnamon has a more aação com a canela falsa. A falsa canela tem sabor mais adstringent taste and contains a highee e contém maior concentration of coção de cumarin in itsa em sua composition. Consuming large amounts of coção. O consumo de grandes quantidades de cumarin can lead toa pode acarretar efeitos adverse health effects, thus os à saúde, justifying its lower cost in the market. As a icando assim o seu menor custo no mercado. Como result, true cinnamon isado, a canela verdadeira é susceptible totível a fraud due to itses devido à sua quality and high value, and false cinnamon is often used as adade e alto valor, e a canela falsa é frequentemente usada como substitute and/oro e/ou adulterant, both in powdered form and as a CEO. In e, tanto na forma detail, in just over the last thirteen years, cinnamon haspó quanto como CEO.

A received significant attention by the scientific community. The search employed specific terms, including “true and false cinnamon”, “Cinnamomum verum arantia da qualidade, segurançand Cinnamomum cassia”,e “authenticity of cinnamon essential oil”, or “cinnamon adulteration”, and focused on articles where these terms appeared in the field title, abstract, and keywords. The intention was to exclude publications unrelated to the subject matter. The search encompassed the entire period from the inception of the Scopus database up to 2010, with the final retrieval conducted in September 2023. Figure 1 dade dos OEs é uma preocupação primordial devido às suas composições complexas. Os OE, derivados de várillustrates the upward trajectory of scientific publications related to cinnamon over time. This is evidenced by a total of 120 scientific papers published in recent years. Thes partes de plantas, abrangem uma gama diversificada de compostos assurance of quality, safety, and authenticity of EOs is a paramount concern due to their intricate compositions. EOs, derived from various plant parts, encompass a diverse array of aromatic compounds, each contributing to their distinct aromas and potential therapeutic properties. As these oils find their way into numerouomáticos, cada um contribuindo para os seus aromas distintos e potenciais propriedades terapêuticas. À medida que estes óleos chegam a numerosos products in industries ranging from food and cosmetics to pharmaceuticals, ensuring their purity andtos em indústrias que vão desde a alimentar e cosmética até à farmacêutica, garantir a sua pureza e legitimacy becomesidade torna-se imperative to safeguard o para salvaguardar o bem-estar do consumeridor.

Uma well-beinfing. Aidade pldethora of techniques have been detailed in the scientific literature to address the técnicas foi detalhada na literatura científica para abordar a natureza multifaceted nature of EOs. These methada dos OE. Essas metodologies span a as abrangem um espectrum from traditionalo desde avaliações organoleptic assessments, which iépticas tradicionais, que envolve humanm avaliações sensory evaluations, to more advanced and precise analytical methods. Physical, chemical, andiais humanas, até métodos analíticos mais avançados e precisos. As abordagens físicas, químicas e instrumental approaches play pivotal roles inis desempenham papéis fundamentais na verifying theicação da genuineness ofidade dos CEOs. S

Técnicas espectroscoópic techniques, such asas, como espectroscopia de infrared and nuclear magnetic resonance spectroscopy, provide insights into thevermelho e ressonância magnética nuclear, fornecem informações sobre a estrutura molecular structure of EOs, aiding in theirdos OEs, auxiliando na sua identification and authção e autentication. Chção. Métodos cromatographic methods, such as gas cháficos, como cromatography-mass fia gasosa-espectrometryia de massa (GC-MS) and high-performance liquid chromatographye cromatografia líquida de alta eficiência (HPLC), enable thepermitem a separation andção e quantification ofção de compostos individual compounds within theis dentro das matrizes complex EO matrices. These techniqueas de EO. Estas técnicas serve as valuable tools for pinpointing specific markers that can m como ferramentas valiosas para identificar marcadores específicos que podem distinguish authentic CEOs fromr CEOs autênticos de versões adulterated or counterfeit versiondas ou falsificadas.

2. Cinnamomum sp.

CiA cannamon is a spice belonging to the genusela é uma especiaria pertencente ao gênero Cinnamomum da in the família Lauraceae family, and it is widely used across varioue é amplamente utilizada em várias cultures around theas ao redor do mundo [ world15 ^[15]]. TheO name “cinnamon” isome “canela” é derived from the Greek word, meaning “sweet woodado da palavra grega, que significa “madeira doce” ^[16][ 16 ]. ItÉ is auma árvore perennial tree that can grow to heights of 7 toe que pode atingir alturas de 7 a 10 m, although it can also beembora também possa ser cultivated as a shrub, reaching less than 3 m in height. Cinnamon thrives in tropical, warm, and humidda como arbusto, podendo atingir menos de 3 m de altura. A canela prospera em climates, and it becomes ready for harvest after about three years of growth. It features dark green leaves, small white-yellowish flowers, and purple fruits that contain a single seeds tropicais, quentes e úmidos e fica pronta para a colheita após cerca de três anos de crescimento. Possui folhas verde-escuras, pequenas flores branco-amareladas e frutos roxos que contêm uma única semente [ 3 ^[3]]. ACeround 250 to 350 species of cinnamon have been ca de 250 a 350 espécies de canela foram identified andcadas e distributed across North America,ídas na América do Norte, América Central America, South America, Southeast Asia, and, América do Sul, Sudeste Asiático e Australia. Among these speália. Dentre essas espécies, four arequatro são considered of greateadas de maior importance and are commonly used for obtaining the spiceância e são comumente utilizadas para obtenção da especiaria: Cinnamomum zeylanicum Blume (talso known asmbém conhecida como C. verum ), Cinnamomum aAromaticum (oru C. cassia ), native toa da China, Cinnamomum burmannii , native toa da Indonesia, andésia e Cinnamomum loureiroi , native to do Vietnamã [ 17 , 18 ^[17][18]]. ItsSeu consumption iso está associated with healthdo a benefits such asícios à saúde, como atividade antimicrobialna [ activity19 ^[19]], propriedades antioxidant propes [ 20 ], eferitieos ^[20], anticancer ígeffectsnos [ ^[21],21 and] glucose control ine da glicose no diabetes ^[22][ 22 ]. CiA cannamon isela é utilized in foods, seasoningada em alimentos, temperos, cosmetics, andéticos e medications, and is available in varioumentos, e está disponível em diversas forms, such as whole material, groundas, como integral, moída, extracts, ortos ou óleos essential oils obtained from the leaves and bark. However, theciais obtidos das folhas e cascas. No entanto, o consumption of cinnamon may also lead too de canela também pode causar efeitos adverse health effectsos à saúde. TO trans -cinnamaldehyde, also known as cinído, também conhecido como cinamaldehyde, the mainído, principal component of cinnamon bark, can e da casca da canela, pode result in skin sensitization and cause contactar em sensibilização da pele e causar dermatitise de contato [ 23 ^[23]]. O ácido Cinnamic acid is also known to induce hycinâmico também é conhecido por induzir hipersensitivity uponbilidade ao contactto ^[24][24 ]. TA canela verue cinnamondadeira native ta do Sri Lanka, also known astambém conhecida como Ccaneylon cinnamla do Ceilãon , includei as the speespécies C. verum ande C. zeylanicum , and false cinnamon, which have diverse origins such as e a canela falsa, que tem origens diversas como China, South America, and Indonesia, andAmérica do Sul e Indonésia, e include the speciesi a espécie C. cassia , C. aromaáticumo , C. burmannii, ande C. loureiroi [ 25 ^[25]] ( Tabelea 1 ). TheO aroma and taste of true cinnamon are soft and sweet, and its color is light brown, whereas fake cinnamon is darker, in addition to having a stronger, ae o sabor da canela verdadeira são suaves e doces, e sua cor é marrom claro, enquanto a canela falsa é mais escura, além de possuir sabor mais forte, adstringent, and spicye e picante [26 flavor] ^[26]. InAlém addition, they have distinct chdisso, possuem caracteristics regarding thísticas distintas quanto à composição de composition of phenolic compounds, with true cinnamon being rich in aromatic and phenolic compounds, such as cinntos fenólicos, sendo a canela verdadeira rica em compostos aromáticos e fenólicos, como cinamaldehyde and ído e eugenol, while false cinnamon has higher amounts of coenquanto a canela falsa possui maiores quantidades de cumarin (2000 to 5a (2.000 a 5.000 mg/kg), approximately a thousand times higher than those found in true cinnamon (2 to 5 mg/kg), and tannins in the bark, which explains the adamente um mil vezes superiores aos encontrados na canela verdadeira (2 a 5 mg / kg) e taninos na casca, o que explica o sabor adstringente [ taste25 , 27 , 28 , 29 ^{[25][27][28][29]}]. CoA cumarin is ana é um agente anticoagulant agent that can pose serious health risks due to ite que pode representar sérios riscos à saúde devido aos seus efeitos hepatotoxic andóxicos e carcinogenic effects inênicos em animals. For this reason, health agencies havis. Por esse motivo, os órgãos de saúde establishedeleceram restrictions regarding the tolerable daily intake of coções quanto à ingestão diária tolerável de cumarin, thus a, determining the daily intake at 0.nando assim a ingestão diária de 0,1 mg/kg/day, and ia e, consequently theemente, o consumption ofo de C. cassia , guaranteeing its safe usearantindo seu uso ^[30][31]. Thse Eguropean [ 31 , 32 ]. O Regulamention (EC) Noo Europeu (CE) n.º 1334/2008 ^[32][ 33 ] estabelished specific coeceu limites máximos específicos de cumarin maximum limits as followsa como segue: 50 mg/kg forpara produtos de panificação traditional and/or seasonal bakery products with cinnamon mentioned in their labelingcionais e/ou sazonais com canela mencionada na sua rotulagem, 20 mg/kg for breakfast cerealspara cereais de pequeno-almoço, includingindo muesli , 15 mg/kg for fine bakerypara produtos de panificação fina (excluindo products (excludingtos de panificação traditcional and/or seasonal bakery products with cinnamon in the labeling), ande/ou sazonal com canela na rotulagem) e 5 mg/kg for dessertpara sobremesas. InEm general, C. loureiroi contém ains high levels of coltos níveis de cumarin, which can cause adverse side effects for thea, o que pode causar efeitos colaterais adversos ao consumeidor, including liver damage. True cinnamon, on the other hand, is highlyindo danos ao fígado. A canela verdadeira, por outro lado, é altamente vulnerable toável a fraud due to its added value and highees devido ao seu valor agregado e maior qualitydade em compared to falseação à canela falsa [ cinnamon34 ^[33]]. C. verum é uma especiaris a highly prized spice and isa muito apreciada e consideredada superior to false cinnamon, which is commonly found and cheaperà falsa canela, que é comumente encontrada e mais barata. Visually, the bark cinnamon appears in the form of rolled cylinders. However, the true cinnamon has a light reddish-brownmente, a casca da canela aparece na forma de cilindros enrolados. Porém, a canela verdadeira apresenta color rolled in several layers, while the others are in dark reddish-brown tones, hard, and rolled in only one layeração marrom-avermelhada clara enrolada em várias camadas, enquanto as demais são em tons marrom-avermelhados escuros, duras e enroladas em apenas uma camada [30 ] ^[34]. TheAs different parts of cinnamon bark, leaf, or powder, have differences ines partes da casca, folha ou pó da canela apresentam diferenças na compositionção ( Figurea 21 ), whichque can be used for qualitypodem ser utilizadas para control. The bark, for examplele de qualidade. A casca, por exemplo, containém antioxidantes natural antioxidants, while the branches are used to treatis, enquanto os galhos são utilizados no tratamento de doenças inflammatory diseases. Cinnamon bark powder, when added with othermatórias. O pó da casca de canela, quando adicionado a outros medications, can slow down thmentos, pode retardar o processo de deterioration process of some heart conditionsção de algumas doenças cardíacas [ 35 , 36 , 37 ^[35][36][37]].

2.1. CinnamÓleon Essential Oicial de Canela

CEOs are complex mixtures of aromatic products from the secondary metabolism of plants, normally produced by secretory cells or groups of cells from different parts of the plant, such as stems, roots, leaves, flowers, and fruits ^[38][39][38,39]. The essential oil content may vary according to the species, physical form of the sample, part of the plant used (Table 2), geographical origin, and stage of development of the plant [3]. The constituents of CEOs can belong to several classes of compounds, with emphasis on terpenes and phenylpropenes, which are the classes of compounds commonly found. Monoterpenes and sesquiterpenes are the most frequently found terpenes in EOs, as well as diterpenes, and minor constituents [40]. Different parts of cinnamon, bark, leaves, branches, fruits, and roots can be used for the production of essential oils by distillation and oleoresins by solvent extraction [41]. The volatile components of the EO are present in all parts of the plant (Table 2) and can be classified into monoterpenes, sesquiterpenes, and phenylpropenes, with main constituents such as trans-cinnamaldehyde (bark), eugenol (leaves), and camphor (root) ^[3][42][3,42]. activities. Despite having good biological properties, eugenol has low solubility in water ^[53][55], and sensitivity to light ^[52][54]. CEO contains some vital bioactive components in the form of terpenes and aromatic compounds, giving it remarkable biological properties. Thus, CEO has been widely used as a raw material in the medicine industry, as natural additives, condiments, and flavorings in the food industry, and in perfumery ^[42][54][42,56]. The main responsibility for the biological activities is often attributed to the major compounds present in the oil, such as the volatile fraction and the phenolic compounds ^[55][57]. In addition, biological activities can also be related to the joint contribution of different compounds, with minor components producing a synergistic effect with the others ^[3][56][3,58]. Table 3 provides an overview of the diverse biological activities associated with various species of Cinnamomum. The compounds found in cinnamon have demonstrated a wide range of biological effects, including antimicrobial, anti-inflammatory, antioxidant, insecticidal, and antidiabetic activities. This compilation highlights the multifaceted potential of Cinnamomum in various fields, from traditional medicine to modern pharmaceutical research, pest control, and diabetes management. Cinnamaldehyde is a yellowish oily liquid responsible for the strong odor and sweet taste of cinnamon [17] and the main constituent of EO. It is recognized as safe by the United States Food and Drug Administration and the Association of flavor and extract manufacturers, receiving status A, that is, it can be used in food ^[43][45]. Its commercial use is limited due to its low solubility in water and sensitivity when exposed to light and air for prolonged periods ^[44][46]. Friedman; Kozuke; Harden ^[45][47] evaluated the stability of trans-cinnamaldehyde present in EO at different temperatures and observed that around 60 °C the compound was decomposed. Das, Gitishree et al. ^[46][48] report that cinnamaldehyde has a biological effect and is quickly oxidized into cinnamic acid, and as a product of its degradation, benzoic acid is excreted by the urinary system. Due to cinnamic acid and cinnamaldehyde, cinnamon has protective effects against cardiotoxicity produced by the compound isoproterenol ^[47][49]. In addition, cinnamon is associated with the inhibition of fatty acids such as arachidonic acid, which has an inflammatory effect. The compound eugenol, identified in cinnamon extracts, has an antioxidant effect, helping to inhibit lipid peroxidation and the generation of reactive oxygen species ^[48][50]. Eugenol is the main volatile compound of OECF ^[49][51]. It is an aromatic substance with a pleasant odor and taste, belonging to the class of phenylpropanoids ^[50][52]. It is usually found as a yellowish oily liquid ^[51][53]. Like cinnamaldehyde, eugenol is also recognized as a safe food by the Food and Drug Administration ^[52][54]. Eugenol has antimicrobial ^[4][5][4,5], antifungal ^[6][7][6,7], anti-inflammatory ^[9][10][9,10], and antioxidant ^[11][12][11,12] CEO can be used in culinary preparations due to its sweet and spicy aroma and flavor. It is generally used in seasonings for meat, fish, sauces, roasts, and beverages; in bakery and pastry products as an alternative to preservatives [13]; and in chewing gum as a flavoring agent [14]. With the growth in demand in the food, perfumery, and cosmetics industries, the market for natural aromatic raw materials is expanding exponentially to meet your needs. To meet this search for aromatic products, research has focused on compounds from biotechnological processes used in the production of aromas and fragrances from other plant origins ^[78][80].

2.2. Adulteration of Cinnamon Essential Oils (CEOs)

With the growth in demand in the food, perfumery, and cosmetics industries, the market for natural aromatic raw materials is expanding exponentially to meet your needs. To meet this search for aromatic products, research has focused on compounds from biotechnological processes used in the production of aromas and fragrances from other plant origins ^[78][80]. Intentionally altered products with hidden properties or quality and incomplete and unreliable information define adulteration. In general, counterfeiting involves actions that deteriorate the specific properties of the products while maintaining their characteristic indicators, such as appearance, color, consistency, and aroma ^[79][81]. Currently, the authenticity of food and food ingredients is a major challenge, as it is often related to fraud. Food adulterations have been occurring for a long time, with the difference that they have been improved over the years, accompanying or even advancing in the field of research into new methods. A greater number of adulterations among raw materials are found in spices, edible oils, honey, milk and its derivatives, fruits and fruit juice, coffee, flour, and meat products [26]. Among the raw materials, cinnamon is one of the spices commonly adulterated. These adulterations can include species (mixing different species of Cinnamomum), origin (incorrectly labeling the country of origin), additives and fillers (adding other substances such as starch, sawdust, or other spices), and oil (adulterating EOs derived from cinnamon with synthetic or cheaper oils). Due to its high added value and high cost, true cinnamon is highly prone to adulteration with false cinnamon species, which are of lower quality and cheaper, causing potential health risks and making the product unsafe for the consumer. This practice is usually carried out in powder form, which makes it difficult to discriminate between cinnamons as their characteristics are lost during the process [29]. Furthermore, true cinnamon can be adulterated with other types of spices, such as clove and chili powder, and clove and cinnamon oil, as reported by Gopu et al. ^[80][82]. Cinnamon fraud triggered research for the development of new, more accurate, reliable, and sensitive analytical methods in order to identify and quantify potential adulterants in true cinnamon more quickly and efficiently, ensuring food safety. Among the methods developed, chromatography is based on the determination of the main active compounds of cinnamon or adulterants, called marker compounds, such as cinnamaldehyde, eugenol, linalool, and coumarin, among others ^[80][82]. Cinnamon adulterations do not only occur in the form of powder, frauds are also found in CEO by mixing other compounds or even false cinnamon species. Through physical–chemical and instrumental analyses, the CEOs purity can be proven through qualitative and quantitative analyses, that is, determining the constituents or identifying the compounds present in the oil, respectively ^[79][81]. To prevent the entrance of adulterated cinnamon products into local markets, the regulatory sector takes several steps: product testing and certification are performed by implementing regular product testing to verify the authenticity and quality of cinnamon products; certifying authentic products with recognized standards can help consumers identify genuine products; labeling regulations require accurate information about the species, country of origin, and any additives or fillers in the product; clear and transparent labeling helps consumers make informed choices; traceability systems that track the supply chain of cinnamon products from production to market, which can help identify and eliminate adulterated products at different stages; import controls and inspections to ensure that products entering the country meet regulatory standards, which includes checking for proper documentation and compliance with labeling regulations; public awareness and education about the different types of cinnamon and their characteristics—informed consumers are less likely to purchase adulterated products; penalties and enforcement for those found guilty of adulteration, and rigorous enforcement of these penalties, which can act as a deterrent to unethical practices; collaboration with industry and associations to establish self-regulation practices and codes of conduct that promote authenticity and quality; and international cooperation with international regulatory bodies and other countries to share information and best practices in combating cinnamon adulteration, especially when products are imported. For the regulation of EOs, the molecules must come from the raw material of the reference plant to be considered and labeled as 100% pure and natural ^[78][80]. Adulteration of CEOs can be divided into four types ^[79][81]: essential oil diluted with a solvent that has similar physicochemical characteristics, such as vegetable oils or organic solvents; cheaper CEO, but similar in origin or chemical composition, mixed with authentic CEO; unique natural or synthetic compounds added to mimic aromatic characteristics or composition; and/or substituting with low-value or blending CEOs. As they are complex matrices, the EOs need to be analyzed by different techniques to ensure quality, safety, and authenticity, in addition to ensuring safety for consumers. As a result, a wide range of techniques have been reported, including organoleptic, physical, and chemical methods. However, these techniques, for the most part, require specialized people, have a high investment cost, are time-consuming, and some degrade the samples ^[79][81][81,83]. Molecules produced from natural reagents, also known as semi-synthetic compounds, can be used to adulterate specific EOs ^[78][80]. Cinnamaldehyde molecules can be produced from the benzaldehyde found in bitter almonds and used as an adulterant ^[82][84]. There are several scams associated with bitter almond and CEO, and since the false origin is cheaper than the Ceylon origin, blends between these CEOs are common. Despite this, it is possible to detect this type of adulteration by analyzing differences in composition between EOs or by spectroscopic analysis ^[26][28][78][26,28,80]. As adulterations along the food chain ções ao longo da cadeia alimentar represent a health hazard, and continuous vigilance isam um perigo para a saúde e a vigilância contínua é fundamental in terms of food safety, regarding research and development of analytical methods toem termos de segurança alimentar, no que diz respeito à investigação e desenvolvimento de métodos analíticos para detectar adulterations andções e contamination in food from the raw materials usedções nos alimentos a partir das matérias-primas utilizadas [26 ] ^[26].