Introduction
Herbal infusions date back to 1606 and had already gained popularity in Europe long before the introduction of traditional tea by the Dutch East India Company. Since then, the global herbal tea market has experienced substantial growth, with a significant increase in consumer interest in healthier dietary choices.[Citation1] Similarly, the sector for both organic and conventional spices and herbs, integral to herbal tea production, is rapidly expanding and is projected to reach nearly $31.95 billion by 2028. This trend has led to the rapid expansion of the functional foods and beverages market, within which herbal teas occupy a significant niche.[Citation2] Today, many species of herbal teas are appreciated by consumers for their potential health benefits, which may include properties such as anti-inflammatory, antioxidant, digestive, calming, and immune-boosting effects.[Citation3–5] Herbal teas, like traditional teas, have evolved from being solely health drinks to becoming popular in social and recreational settings. They are now available in convenient formats such as single-serving sachets, loose leaves, and ready-to-drink solutions.[Citation6]
The concept of “tea time” as a recreational and social ritual depends on various factors, including the availability of indigenous aromatic and medicinal plants, cultural influences, and consumer preferences.[Citation2–4] Consumers select herbal teas based on taste, aroma, appearance, and health properties. However, despite the beneficial effects often attributed to herbal teas, concerns about safety persist.[Citation3,Citation7] Adverse reactions have been reported in some individuals, highlighting the need for regulatory standards to ensure product safety. Contaminants such as fungi and mycotoxins, potentially present due to inadequate production controls, have been linked to these adverse reactions.[Citation7,Citation8] Herbal teas are generally perceived as health-promoting beverages. However, several studies have reported the presence of chemical and microbiological contaminants in these products. As highlighted by Kowalska,[Citation8] significant levels of lead were detected in herbal raw materials used for herbal tea production. It is crucial to emphasize that heavy metal contamination can vary depending on the geographic origin and agricultural practices employed. Feng et al.[Citation9] detected numerous pesticides and their metabolites in various samples, with concentrations exceeding the permissible limits. The study by Reinholds et al.[Citation10] revealed high fungal and mycotoxin contamination in tea and herbal tea samples marketed in Latvia, particularly regarding aflatoxins and deoxynivalenol. Additionally, Chalyy et al.[Citation11] investigated the transfer rate of mycotoxins from dry herbs to the infusion, demonstrating that the polarity of mycotoxins and the pH of the infusion significantly influence this process.
The cited studies assessed health risks using indicators such as the Target Hazard Quotient (THQ) and the Hazard Index (HI). While the results in some cases were generally reassuring, it is important to stress that risk assessment is a complex process and long-term exposure to low doses of contaminants may have cumulative effects.[Citation9–11] The choice of organic products, sourced from regions with lower environmental pressures and subject to rigorous quality controls, can help reduce exposure to these contaminants. Moreover, it is essential to promote greater awareness among consumers and industry operators about the importance of sustainable production and consumption practices. The herbal tea industry is rapidly evolving, with companies continually seeking new flavors to meet consumer demands. However, concerns about product safety have not kept pace with this rapid development.
It is imperative for companies to provide accurate information not only about the benefits of herbal teas but also about sustainable production practices. This not only enhances consumer awareness but also increases the perceived value of these products, leading to greater consumer willingness to purchase and pay for a safe and healthy product.[Citation12] The existing literature on the herbal tea market tends to be more theoretical or based on small-scale studies rather than large-scale empirical research.[Citation13] This scarcity of empirical studies highlights the need for more focused research efforts to better understand consumer behavior, market dynamics, and the potential health benefits and risks associated with herbal tea consumption.[Citation14]
Considering this context and to gain a comprehensive understanding of the state of the art of herbal tea in the market, this research aims to shed light on the opportunities and challenges within the herbal tea sector. The following research questions guide this study:
R1:
What are the current trends and consumption behaviors of herbal tea consumers?
R2:
How is the herbal tea market evolving, and what are the main factors influencing its growth?
This integrated approach aims to delve into the existing literature to uncover prevailing interests, evolving trends, and interconnections within the field of herbal tea consumption. By utilizing robust bibliometric and network analysis techniques, we provide comprehensive insights into the themes and connections within this sector. Simultaneously, through a critical examination of existing literature, the paper seeks to highlight the potential of the herbal tea supply chain, particularly in the European context. By synthesizing this research and identifying gaps and opportunities, we aim to offer practical recommendations for businesses to navigate sustainable production practices and capitalize on emerging market trends.
Materials and methods
Literature search method
The systematic literature review was conducted using two scientific databases: Scopus and Web of Science (WOS). An identical search string was applied in both databases via the advanced search mode. The absence of restrictions in the search string allowed for the gathering of documents from various scientific fields, including ethnobotany, agriculture, pharmacy, chemistry, biochemistry, molecular biology, and social sciences. This approach aimed to comprehensively understand the most debated research topics, addressing the first research question.
The search strings used were:
Scopus String: TITLE-ABS-KEY ((“herbal tea*”) AND (consum*) AND (market)).
WOS String: TS= (“herbal tea*”) AND TS= (consum*) AND TS=(market).
These search strings, consisting of keywords combined with Boolean operators, were chosen to frame the research scope, covering aspects related to herbal tea consumption and the socio-economic dynamics of these products. Both search strings were utilized for document collection until the date of February 2024, with the aim of not limiting the field of study, but rather to explore, for the first time, herbal tea consumption in a more comprehensive manner.
The research questions were formulated by specifying all the key elements of the PICo statement, that is a valuable framework commonly used in systematic literature reviews, particularly in the context of health sciences and clinical research. PICo (with the lowercase o) is a variant of PICO to analyse human experience or a social phenomenon which consider the following elements[Citation15,Citation16]:
PICo R1:
• P (Population):economic agents involved in the consumption of herbal teas;
• I (phenomenon of Interest): consumption drivers of herbal teas;
• Co (Context):worldwide after 2015.
• PICo R2:
• P (Population):economic agents involved in the herbal tea market;
• I (phenomenon of Interest): market factors;
• Co (Context):worldwide after 2015.
While R1 dives deeper into consumer behaviour, preferences, and the impact of global integration on local cultures and health awareness, R2 aims to discuss market growth, the economic potential of the herbal tea industry, and the implementation of integrated strategies for managing the value chain, emphasizing collaboration and structured governance to achieve sustainability goal. To effectively address these questions, the study utilized both bibliometric and network analysis using VOSviewer software, while systematically adhering to PRISMA 2020 guidelines.
In the inclusion of databases, databases such as PubMed and Embase were not considered as they mainly focus on biomedical and clinical research, whereas our study aims to explore the herbal tea market from an economic and consumer behaviour perspective. Scopus and Web of Science (WOS) were selected as they provide a broader coverage of literature in social science, economics and food-related studies, aligning more closely with our research objectives.
The timeframe from 2015 to 2024 was chosen to capture recent developments in the herbal tea market, considering changes in consumer preferences, regulatory frameworks, and industry trends. Studies prior to 2015 were excluded to ensure that the findings remain relevant to the current market landscape and emerging research directions.
PRISMA model
The updated PRISMA 2020 model for systematic reviews and meta-analyses enhances the replicability, accuracy, and comprehensiveness of literature reviews by providing a structured framework. This model is designed to improve transparency by ensuring that each stage of the review process is clearly documented and reported.[Citation17] It includes three main phases: identification, screening, and inclusion of studies. In the identification phase, all potentially relevant studies are retrieved through searches in selected databases and other sources. During the screening phase, duplicates are removed, and the remaining studies are screened for relevance based on predefined criteria.
The eligibility phase, now incorporated into the screening phase, involves a more detailed assessment of full-text articles to ensure they meet inclusion criteria. Finally, in the inclusion phase, studies that meet all criteria are included in the qualitative and, if applicable, quantitative synthesis. The PRISMA 2020 model also encourages researchers to report the reasons for exclusion at each stage, contributing to a more transparent and reproducible review process.[Citation18,Citation19] In this study, the PRISMA 2020 model guided the selection of significant articles on the herbal tea supply chain and facilitated a systematic summary of the relevant findings.
Identification
The identification phase involved selecting specialized databases and suitable sources for conducting the review. A composite search string consisting of three keywords (“herbal tea*”, “consum*”, “market”) combined with Boolean operators was employed. Scopus and Web of Science (WOS) databases were used. Additionally, relevant article, primarily of economic nature, were identified and downloaded from Google Scholar to enhance the review’s comprehensiveness.
Screening and inclusion phase
To ensure that the results are up-to-date, we selected a specific timeframe covering the last decade (2015–2024) in both databases. We filtered the articles based on document type, considering only articles and only academic literature in English. The retrieved records were then exported, downloaded, and subsequently uploaded to Rayyan.ai, an artificial intelligence platform designed to assist in eliminating duplicate entries during the identification phase and to expedite the screening process. This user-friendly tool allowed for efficient selection of relevant articles through its intuitive graphical interface.
The screening phase involved two crucial steps: initially, titles and abstracts relevant to the research topic were reviewed, with irrelevant articles being excluded. Subsequently, the full text of the remaining articles was thoroughly examined for eligibility and inclusion. Only articles specifically addressing “herbal teas” were included, while those focusing solely on the “nutritional aspects” of herbal teas were excluded, as they were deemed unrelated to the research objectives. Finally, 35 articles met the inclusion criteria in the review and were included in the final study. depicts the PRISMA search flow diagram.
Figure 1. PRISMA 2020 flow diagram for new systematic reviews which included searches of databases, registers and other sources. Own elaboration following the PRISMA model.
For better clarity and understanding of the flowchart reading, the inclusion and exclusion criteria are shown in .
Table 1. Inclusion and exclusion criteria description.
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Network analysis
The study relied on the VOSviewer tool, a JAVA-based software developed in 2009 by Van Eck and Waltman in the Netherlands.[Citation20] This tool specializes in creating network maps from data and facilitates network analysis by processing bibliometric maps. Through statistical keyword analysis, commonly used terms and their relationships were identified, revealing key research topics within the field under study.[Citation21] This analysis was crucial for evaluating trending research topics and offering insights into potential future trends.
VOSviewer software was employed for its expertise in co-occurrence analysis and graphical representation of topic-related networks.[Citation22] Data from Scopus, Web of Science (WOS) databases and Google Scholar were integrated into VOSviewer to ensure a comprehensive depiction of keywords relevant to the research focus.
Results
Descriptive analysis
In the last decade, there has been a rising interest in the scientific community regarding the study of herbal teas, including their market and consumption. This is demonstrated by the trend observed in , which shows a significant increase in publications on these topics between 2019 and 2023, compared to previous years. Excluding the current year, 2024, this trend suggests a growing focus on these topics by scholars and researchers in the academic field. Upon analyzing the data presented in regarding the geographical origin of publications, it is evident that China dominates the production of studies and surveys concerning herbal teas, the market, and consumption. The figure includes publications that can be viewed on Scopus and WOS. A growing position is emerging for South Africa as a major contributor of research on this topic, but only on the Scopus database.
Figure 2. (a) Number of articles published per year, between 2015 and 2023, selected and broken down in the scopus and WOS databases. Own elaboration through the excel software.(b) Distribution of articles by country and database. The horizontal axis shows the number of articles, and the vertical axis lists the countries. Articles from scopus are in orange, and those from Web of Science (WoS) are in blue. Own elaboration through the excel software.
provide insights into the emerging thematic areas within herbal tea research, market, and consumption. , based on the Scopus database, highlights the significant development of research in the areas of agriculture and life sciences, suggesting a growing interest in the impact of herbal teas on crops and biodiversity. However, according to , which is related to the WOS database, the category ‘Food Science and Technology’ emerges as one of the main areas of study. This indicates a focus on the analysis of the technological and nutritional aspects of herbal teas, as well as their effects on the market and the consumer. Research on herbal teas, the market, and consumption is therefore continuously changing and encompasses a variety of disciplines and viewpoints. By analyzing the data, we can respond to the initial research question and pinpoint areas that require further study in this quickly developing subject.
Figure 3. (a) Distribution of subject areas of the articles in the review. The vertical axis shows the subject areas from scopus, while the horizontal axis shows the number of articles in each area.Own elaboration through the excel software.(b) Distribution of article categories in the review. The vertical axis shows categories from the Web of Science (WOS), while the horizontal axis shows the number of articles in each category.Own elaboration through the excel software.
Network analysis results
For the co-occurrence analysis, a minimum threshold of 2 occurrences of keywords for inclusion was set. Redundant and tangential keywords were subsequently eliminated, resulting in a selection of 29 keywords grouped into 4 clusters by VOSviewer, 204 links and 371 Total link strength. This process made it possible to construct a network based on these categorized keywords, visually represented in and listed in , which shows the cluster to which each keyword found by VOSviewer belongs, the number of links and total link strength and the number of occurrences. The larger the line size, the stronger the connection in terms of citations.[Citation23] By observing the thickness of connecting lines in the network, indicative of citation strength, the strength of associations between keywords was discerned. This visual representation aided in understanding the primary research directions within the topic area, providing a comprehensive response to research inquiries.
Figure 4. Map of the keyword network analysis generated using VOSviewer. Colours distinguish the four main clusters identified in the analysis: consumption habits (red), food safety concerns (green), risks associated with product consumption (blue) and herbal tea market (yellow). Own elaboration through VOSviewer software.
Table 2. Occurrences of keywords and their strength links.
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The resulting network revealed four distinct clusters, each characterized by a different colour. The first cluster (red) focused on aspects related to beverage consumption and consumer socio-cultural behaviour, garnering the highest number of citations and exhibiting the strongest connections.
The second cluster (green) focuses on the risks associated with herbal tea consumption, including microbiological and chemical concerns.
The third cluster (blue) emphasized safety measures to mitigate the toxicity of herbal products and the associated health risks for consumers, while the fourth cluster (yellow), the smallest, highlighted market dynamics, particularly the dominance of the Chinese market in herbal tea production and consumption. The red cluster contained 20 articles, the green cluster contained 19 articles, the blue cluster contained 17 articles, and the yellow cluster contained 4 articles.
provided further insights into the relationships and significance of individual keywords within each cluster, demonstrating that even keywords with lower overall connection strength could exert significant influence within specific subsets of highly cited words.[Citation24]
A minimum threshold of two occurrences was set to ensure the inclusion of relevant keywords while avoiding excessive fragmentation of the dataset. Although alternative thresholds could have been explored, the chosen value provided a well-structured network with meaningful clusters, making further sensitivity analysis unnecessary for the scope of this study.
Through an analysis of keywords and their co-occurrence, four primary research clusters were identified, covering topics such as consumption habits, food safety concerns, risks associated with product consumption, and the theme of the herbal tea market.
Discussion
The bibliometric examination and network analysis performed using VOSviewer have provided an essential framework for synthesizing the prevalent themes and their interconnections within the herbal tea market literature.
By mapping out the relationships between various aspects of the herbal tea market we have gained critical insights.
The visualization through network analysis facilitated a deeper understanding of how these dimensions are interlinked, setting the foundation for the subsequent discussion of the main results.
The most representative keywords highlight the thematic focus of each cluster: in the first cluster, “herbal medicine” and “consumer” are most prominent; in the second, “risk assessment” and “food contamination” stand out; in the third, “herbal tea” and “ethnobotany” are key; and in the fourth, “market” and “Chinese market” are central. Therefore, the research discovered four main themes:
Consumption habits, in which consumer attitudes, consumption habits and lifestyle are described.
Food safety concerns, describing the problem of contaminated herbal teas.
Risk associated with product consumption, highlighting the dangers and how to mitigate them through sustainable actions and the study of ethnobotany.
Herbal tea market, highlighting economic dimensions and market dynamics.
Instead, the fifth paragraph of this section aims to highlight the sustainability practices that the herbal tea industry needs to adopt, through new and efficient technologies, improving the supply chain, promoting circular economy practices and obtaining sustainability certifications, in order to consistently communicate its efforts to consumers.
The prominence of the “consumption habits” cluster, as indicated by its high citation strength, suggests that this topic has received significant academic attention. This may be attributed to the increasing consumer interest in health-conscious choices, the diversification of herbal tea products, and the evolving socio-cultural factors influencing purchasing decisions. The broad scope of studies within this cluster also contributes to its strong citation network.
This structured analysis ensures that each research question is comprehensively addressed with robust evidence from the literature, providing clear, actionable conclusions for stakeholders in the herbal tea industry. As we move forward to discuss the main results obtained from this review, it is essential to consider how these findings relate to the broader market dynamics, consumer trends, and the strategic needs of the industry.
Consumption habits
Herbal tea beverages, other than traditional Camellia sinensis L.-based beverages (tea drink), include a wide range of herbal beverages consumed for medicinal purposes. These beverages are particularly popular in regions such as Guangxi, although there is still limited documentation of the specific plants used for herbal teas.[Citation25] In the preparation of these beverages, the fresh leaves of a plant are typically dried and then ground into a powder or “herbal cut” and then used to prepare infusions. In addition to the leaves, various plant fruits and flowers are also used to prepare herbal teas.[Citation26] Herbal consumption habits would improve if more information about their beneficial properties were commercially available. Therefore, scientific research in the field plays a crucial role in guiding and educating consumers.[Citation27] As for herbal tea consumer habits, these are evolving due to multiple factors. Consumer attitudes, influenced by individual perceptions, preferences and motivations, play a crucial role in market dynamics. At the same time, related to herbal tea consumption, continue to exert a strong influence. The modern lifestyle, characterized by a hectic pace and an increasing focus on health and well-being, is redefining consumer choices.[Citation28,Citation29]
The review reveals a diverse landscape of consumer behavior influenced by an increasing awareness of health benefits and cultural factors in individual regions of the world, with their traditions, beliefs and practices. Herbal teas are celebrated for their antioxidant properties, yet consumer knowledge about these benefits varies, influencing purchasing decisions.[Citation30] This variation underscores the necessity for effective information dissemination and tailored marketing strategies that consider demographic variables such as age, gender, and marital status, particularly evident in the consumption patterns of herbal teas.[Citation31] Indeed, while Chinese consumers exhibit extensive knowledge and a favourable attitude toward herbal teas, most consumers lack knowledge regarding the health benefits and usage of herbal teas.[Citation29] Additionally, the integration of global markets has introduced a variety of foreign ingredients and products into traditional food cultures, notably within Europe. Despite this influx, the strong food identity associated with the Mediterranean Diet persists, especially in Italy, where there is a marked preference for local foods.[Citation12,Citation32,Citation33] This preference is not merely a reflection of taste but also a commitment to environmental and social responsibility, with consumers increasingly favoring companies that uphold these values.
The sustainable cultivation of MAPs offers unique environmental benefits, such as reduced water consumption and lower reliance on fertilizers.[Citation34] This approach not only minimizes the ecological footprint of herbal tea production but also contributes to the preservation of biodiversity and soil health. However, the safety of herbal teas extends beyond environmental considerations and encompasses the potential presence of contaminants, chemical residues, and even misidentified plant species. In the wake of the COVID-19 pandemic, there has been a heightened awareness among consumers regarding sustainability, ecosystem balance, and the importance of natural products.[Citation35,Citation36] This shift in consumer preferences has led to increased demand for herbal teas, which are often perceived as healthier and more natural alternatives to conventional beverages.
Food safety concerns
The use of wild food plants in the preparation of fermented beverages and herbal teas presents both opportunities and challenges in terms of food safety.[Citation37] While these plants can offer unique flavours and potential health benefits, they may also pose risks due to misidentification, contamination, or improper preparation methods. Regarding the latter, the decoction process, which requires boiling the plant material, can enrich the products with bioactive compounds, increasing their antioxidant capacity. However, improper preparation may negatively affect the extraction of certain compounds, such as phenols, which are less present in decoctions than in infusions.[Citation38] Therefore, it is essential to conduct thorough research and establish clear guidelines for the safe and sustainable use of wild plants in herbal tea production.
Medicinal and aromatic plants (MAPs), which are widely used in the production and consumption of herbal teas and decoctions, represent a significant opportunity for the development of a sustainable and safe value chain within the food industry.[Citation39,Citation40] This potential is particularly noteworthy due to the increasing demand for natural and healthy products, as well as the growing interest in traditional medicine and alternative therapies. However, ensuring the safety of these products remains a paramount concern for both producers and consumers. This growing demand also necessitates a rigorous approach to ensuring the safety and quality of these products. Ethnobotanical knowledge plays a crucial role in the safe and sustainable utilization of MAPs for herbal tea production.[Citation41] By understanding the traditional uses, preparation methods, and potential risks associated with different plant species, ethnobotanists can help to identify safe and suitable plants for cultivation and consumption. This knowledge is particularly important in regions with a rich tradition of herbal medicine, where local communities have accumulated centuries of experience in the use of medicinal plants. Effective ethnobotanical analysis involves not only the identification of plant species but also the documentation of local names, traditional uses, and preparation methods.[Citation42] This information can be used to develop comprehensive safety guidelines for the cultivation, processing, and consumption of herbal teas.
Additionally, ethnobotanical research can contribute to the preservation of traditional knowledge and cultural practices associated with the use of medicinal plants. Intercultural ethnobotanical studies can provide valuable insights into the diverse uses and safety considerations associated with herbal teas across different cultures and regions.[Citation43] These studies can also foster collaboration and knowledge exchange between different communities, leading to the development of more comprehensive and culturally sensitive approaches to food safety.
The integration of aromatic plants into local agricultural practices, exemplified using Piedmont’s mint and Sardinian myrtle, can contribute to the economic development and cultural identity of specific regions.[Citation44] However, it is crucial to ensure that these practices adhere to strict safety standards and prioritize the well-being of both consumers and the environment. Organic and local certifications can provide consumers with assurance regarding the quality and safety of herbal teas, while also supporting sustainable agricultural practices. The development of a sustainable and safe value chain for herbal teas requires a multi-faceted approach that encompasses environmental considerations, ethnobotanical knowledge, cultural sensitivity, and rigorous safety standards. By prioritizing food safety at every stage of the production process, we can ensure that herbal teas continue to be a valuable and enjoyable part of a healthy lifestyle. Concerns about food safety play a crucial role in consumer choices regarding herbal products. Increasing the availability of reliable information on their safety and benefits could enhance consumer confidence. In this context, scientific research is essential in providing guidance and education to support informed purchasing decisions.[Citation45]
Risks associated with product consumption
The consumption of herbal teas, despite their potential health benefits presents significant risks. Unlike conventional tea, which is generally standardized in terms of production and quality, herbal teas vary significantly in composition and preparation methods.[Citation46,Citation47] This lack of standardization hinders empirical research, as results may not be easily generalizable across different types of herbal teas.[Citation48] Furthermore, different countries have varying regulations regarding the production, marketing, and health claims of herbal teas, hindering the collection of uniform data necessary for robust empirical studies.[Citation49,Citation50] However, the value chain’s development is not devoid of challenges. As Schippmann et al.[Citation51] point out, the lack of structured governance and the risks associated with untraceable, contaminated, and unsafe products pose significant barriers to the sector’s growth and the safety of the end consumers. Addressing these challenges requires a concerted effort to enhance traceability, implement rigorous safety standards, and foster an environment that supports the ethical sourcing and use of medicinal and aromatic plants.[Citation49] Furthermore, organizations such as the International Union for Conservation of Nature (IUCN) have been instrumental in promoting research and raising awareness about sustainable practices, which is vital for preserving indigenous resources and improving the knowledge base around the cultivation and use of aromatic and medicinal plants.[Citation52] However, as discussed above, market expansion also brings with it other challenges. Indeed, the review highlights the presence of chemical, radioactive, and microbiological contaminants in herbal teas, such as pesticides and heavy metals, which in some instances exceed the limits set by the European Union, even if a detailed risk assessment concluded that consumption would not pose health issues.[Citation53] Furthermore, subsequent inspections uncovered heavy metals and other substances posing risks to consumers,[Citation54] along with the detection of natural radionuclides in certain herbal tea batches, raising concerns about consumer exposure levels.[Citation55]
These findings underscore the importance of stringent safety monitoring and the implementation of robust regulatory frameworks to ensure that herbal teas do not pose health risks to consumers. Moreover, specific botanical components, like pyrrolizidine alkaloids found in certain herbal teas, have been identified as genotoxic and carcinogenic, necessitating scrutiny and regulatory oversight to prevent these substances from entering the consumer market.[Citation56] Special attention has been given to chemical contamination by tropane alkaloids (TAs) and ethylene oxide (EO). Tropane alkaloids, such as atropine and scopolamine, are toxic compounds that can contaminate herbal teas due to the presence of Solanaceae species or other toxic herbs, accidentally mixed during harvesting or processing.[Citation57]
Recent studies have shown that a significant percentage of commercial herbal teas are contaminated with these compounds. González-Gómez et al.[Citation58] found that 64% of the samples analyzed contained atropine or scopolamine, with some samples exceeding the EU safety limits for herbal infusions. The presence of such contaminants poses a public health risk, as these substances, being relatively heat-stable, may persist in infusions. Measures such as the adoption of good agricultural practices and the use of technologies like DNA barcoding are crucial in preventing such contamination.[Citation59] Ethylene oxide (EO) is another relevant contaminant in herbal teas. Used as a sterilizing agent, it can leave toxic residues, as demonstrated by several studies highlighting the presence of EO and its derivative 2-chloroethanol (2-CE) in food products, including herbal teas and spices. Patil et al.[Citation60] developed sensitive methods to detect these substances, showing that the primary risk lies in the presence of 2-CE rather than native EO. The presence of these compounds necessitates strict monitoring and the application of safety protocols to avoid dangerous exposures.
Regarding microbiological risks, herbal teas can be vulnerable to contamination by molds, bacteria, and other pathogens during harvesting, drying, and storage. Residual moisture and improper storage conditions can promote the growth of microorganisms such as Salmonella and Escherichia coli, which pose a significant risk to consumer health.[Citation61]
The susceptibility of herbal teas to fungal contamination, which can lead to the production of mycotoxins such as ochratoxin A, further exacerbates these safety concerns.[Citation62] These health risks highlight the imperative for rigorous quality control and safety assessments in the production and distribution of herbal teas. It is worth noting that similar concerns about toxins is not limited in herbal tea, but they exist in various other products, highlighting the broader importance of ensuring safety in food and beverages.[Citation63] In response to these challenges, our review suggests the need for ongoing regulatory developments to ensure the safety and regulation of herbal teas. By enhancing regulatory frameworks and conducting regular inspections, stakeholders can better manage the risks associated with product contamination and ensure that consumer safety is maintained. Additionally, public health campaigns and consumer education about the potential risks and safe consumption practices of herbal teas are essential for mitigating health risks. In addition to what has been said, the substantial market value of these products makes them targets for adulteration and substitution with cheaper alternatives, leading to illegal practices that can undermine consumer trust and safety.[Citation64] To counter these risks, it is crucial for stakeholders to enforce stringent quality controls and transparency in sourcing and production processes.
Herbal teas market
Our research highlights the paucity of empirical studies on the herbal tea market, with only three articles identified throughout the entire review. This lack of research can be attributed to several factors. First, the herbal tea market is highly fragmented, boasting a wide range of products derived from various plants, each with its own unique properties and consumer base. This diversity presents a challenge for conducting comprehensive empirical studies that encompass the entire market. In recent years, many species once found in nature, such as Thymus serpyllum L., Achillea millefolium L., and Chamaemelum nobile, have been cultivated.[Citation5] Among the various plant families compiled by Luczaj et al.,[Citation65] three stand out prominently, with numerous species present in the various herbal tea formulations available on the market. The Lamiaceae family leads with 26 identified species, followed by Asteraceae with 22 species, and Rosaceae with 19 species. While Lamiaceae and Asteraceae species are widespread throughout Europe, Rosaceae species are mainly known as local herbal teas in Eastern and Central Europe.[Citation66] The global diversity of herbal teas is evident in the variety of plants used in different regions of the world. For example, in China, chrysanthemum, jasmine and ginseng herbal teas are particularly popular, while in Japan, drinks such as mugicha (barley tea), sakura flower tea and yomogi (mugwort tea) are commonly consumed. In India, herbal teas based on tulsi, ashwagandha and lemongrass are widely enjoyed, while in the European Mediterranean region, traditional local infusions such as Jasonia glutinosa L. or Sideritis hyssopifolia L. [4] and herbal teas based on chamomile, mint and sideritis predominate. In the Middle East and North Africa, hibiscus (karkadè), anise, and sage are common ingredients, while in South Africa, rooibos and honeybush are favored. In Latin America, mate and boldo are among the most consumed herbal teas. This richness of tradition reflects not only local preferences, but also the cultural and medicinal significance of herbal teas in each geographical context.[Citation67] Moreover, herbal tea can be considered a niche market compared to more mainstream beverages like coffee or traditional tea,[Citation2] further limiting the commercial and academic interest in conducting in-depth empirical research. The emerging global demand for aromatic and medicinal plants, used in herbal teas, not only opens new avenues for trade but also empowers local farmers to diversify their income streams by incorporating these crops into their agricultural activities, thereby enhancing their economic resilience.[Citation68,Citation69] To highlight some of the peculiarities of the mechanisms and dynamics of the herbal tea market, this study can draw parallels with other sectors, as noted by Di Vita et al.[Citation70] and Zarbà et al.,[Citation71] where scenario analysis demonstrated that, despite market growth, not all producers would benefit equally. For instance, small and medium-sized enterprises may encounter challenges in adapting to market demands and supply chain innovations, leading to reduced profitability and, in some cases, market exit for those unable to innovate. For this reason, both small and large enterprises must invest in new marketing techniques such as the benchmark method that detects important information about the perceptions of the benefits of the product for the consumer or for the environment. Thanks to these marketing approaches, it is possible to identify the target consumer more easily.[Citation14] Lastly, the cultural variability of herbal tea consumption patterns across different cultures and regions adds complexity to describing market phenomena. This variability makes it difficult to design studies that capture a representative sample of global or even national markets, potentially leading to inconsistent data and conclusions.[Citation72–74] Consumer demand is certainly higher for tea, especially green tea, but at the same time, there is growth due to the popularity of herbal teas in various markets in Europe[Citation75–78] From the bibliographic analysis of the selected papers, it emerges that the sustained interest is reflected in the market valuation, which indicates that the herbal tea market was valued at USD 2.5 billion in 2022 and is projected to reach USD 4.3 billion by 2032, growing at a compounded average growth rate of 5.6% from 2023 to 2032.[Citation67] Regionally, while Asian countries have traditionally led in consumption, North American and European markets have shown growth trends over the past decade, with China, the United States, Italy, Poland, and Malaysia emerging as pivotal drivers of this growth.[Citation79] This geographical expansion in market growth underscores the global appeal of herbal teas and the opportunities for producers to cater to a diverse and expanding consumer base.
Sustainable practices for the herbal tea industry
The herbal tea industry, while experiencing significant growth driven by consumer demand for health-promoting products, faces critical challenges in ensuring sustainable production and meeting market expectations.[Citation80] To thrive in an increasingly competitive and environmentally conscious market, companies must adopt integrated strategies that address both production efficiency and market communication. A key recommendation is the adoption of energy-efficient technologies, such as renewable energy sources and efficient lighting and drying systems for herbs, which can significantly reduce the environmental impact of production.[Citation81,Citation82] Furthermore, optimizing the supply chain using local suppliers and sustainable materials not only reduces transport-related emissions, but also supports local economies, aligning with corporate social responsibility goals.
Waste reduction is another key aspect to focus on. Circular economy practices, including recycling and reuse of by-products, combined with innovative technologies can help minimize waste generation and improve resource efficiency.[Citation83] Companies should also pursue internationally recognized certifications, such as ISO 14,001, to demonstrate their commitment to sustainability, which is increasingly appreciated by consumers and can strengthen brand trust.
In terms of market communication, herbal tea companies should effectively leverage Integrated Marketing Communication (IMC) to convey a consistent message about their sustainability efforts.[Citation14] The use of social media platforms, events and community involvement can raise awareness among consumers about the environmental benefits of sustainably produced products.[Citation84] Furthermore, promoting biodegradable or compostable packaging solutions or reduced material choice aligns with growing consumer demand for eco-friendly products, providing a competitive advantage in the marketplace.[Citation85]
By integrating sustainable production practices with strategic communication efforts, the herbal tea industry can not only mitigate environmental impacts, but also proactively respond to evolving market trends.
These actions will position companies to meet both consumer expectations and regulatory requirements, ensuring long-term competitiveness and sustainability.
Conclusions and implications
This systematic literature review highlights the need for a comprehensive approach to address the issues related to herbal tea consumption, including strengthening regulatory measures, improving safety monitoring and educating consumers, through important marketing operations and the high level of know-how of individual actors in the supply chain. While the consumption of herbal teas is widely associated with health benefits, the presence of chemical and microbiological contaminants highlighted in the literature suggests the importance of rigorous quality controls and consumer awareness to minimize potential health risks.
The results reveal that economic dynamics and market trajectories significantly influence consumption patterns and drive the evolution of the herbal tea sector. Furthermore, the growing demand for natural and organic products offers opportunities for growth, provided strict quality and safety standards are met. The analysis emphasizes the importance of sustainable production practices, which not only help protect the environment, but also contribute to the socio-economic well-being of local communities. This underlines the need for an industry that embraces both sustainability and safety. However, the work is not without limits.
The generalisability of the findings to real-world practices and policies may be limited due to the variability of cultural contexts, regulatory frameworks and industry practices in different regions. Furthermore, the paper does not present an analysis of the methodologies adopted in the reviewed papers and this could be an approach for future analyses. The difficulties encountered in accessing comprehensive economic studies and data on herbal tea consumption and market development remain, which led to the use of Google Scholar as an additional resource. This limitation highlights the need for a broader and more accessible economic research in scientific databases to support deeper insights into industry dynamics.
Declaration of generative AI and AI-assisted technologies in the writing process
During the preparation of this work the authors used Rayyan.ai to remove duplicate articles downloaded from Scopus and WOS to develop a PRISMA statement. After using this tool/service, the authors reviewed and edited the content as needed and takes full responsibility for the content of the publication.
