Analysis of Tea
Tea is one of the most commonly consumed beverages in the world. It is understood to be a hot or cold beverage made by hot infusion of dried leaves, flowers or herbs in water. Most teas come from the tea plant Camellia sinensis, an evergreen plant that grows in tropical and subtropical regions.
The classic tea varieties are obtained from the tea plant:
- Green tea: unfermented tea
- Black tea: fermented tea
- Oolong tea: semi-fermented tea
Tea contains naturally occurring ingredients such as caffeine, theobromine and theophylline, which can act as stimulants.
There are several tea-like herbs and plants that can be prepared and consumed similarly to tea and are often referred to as "tea" even though they are not derived from the Camellia sinensis plant. Here are some examples:
- Herbal tea: Herbal tea is made from a variety of herbs, spices, and fruits and generally does not contain caffeine.
- Rooibos: Rooibos is a South African shrub whose leaves are dried and made into tea. The infusion is caffeine-free and has a mild, sweet taste.
- Mate tea: Mate tea is made from the leaves of the mate shrub in South America and contains caffeine as well as antioxidants.
- Lapacho tea: Lapacho tea is made from the bark of the lapacho tree in South America and has a mild, woody flavor.
- Chai tea: Chai tea is a blend of black tea, spices and milk popular in India and other countries in South Asia.
Origin & harvest of tea
The tea plant is grown in many countries around the world, but the largest producers are China, India, Kenya, Sri Lanka and Turkey. Other major tea growing countries include Japan, Taiwan, Vietnam, Indonesia and Argentina.
The exact way tea is produced varies depending on the type of tea. In general, however, the production of tea involves several steps:
- Picking: Tea leaves are picked by hand or by machine. For high quality tea, often only the top two or three leaves and the bud are picked.
- Withering: The plucked tea leaves are spread out to lose moisture and become softer.
- Rolling: The wilted leaves are rolled to break the cell structure and promote the release of aromas and flavors.
- Fermenting: In black tea and some oolong teas, the rolled tea leaves are stored in a humid environment to oxidize and form so-called thearubigens. This class of substances defines the typical taste and color of black tea. Green tea is not fermented, but directly steamed or heated to prevent fermentation.
- Drying: The fermented or unfermented tea leaves are dried to remove excess moisture and increase shelf life.
- Sorting: The dried tea leaves are sorted according to size and quality.
- Packaging: The tea is packed and shipped in various forms such as loose leaves, tea bags or cakes.
There are some problems that can occur in the production and consumption of tea, including adjuncts and contamination. Co-herbs are unwanted plants that could be unintentionally harvested and processed along with the tea. Some of these plants may be toxic or have unpleasant taste and odor characteristics. Tea producers must ensure that their products are free of associated herbs to ensure the safety and quality of the tea. Furthermore, contamination of tea with pesticides and heavy metals can occur during cultivation, processing and storage. Microbial contamination is also possible.
The Tentamus Group provides tea analysis services to tea manufacturers, importers, distributors and retailers worldwide.
Tentamus' tea analyses help tea manufacturers and other industry players ensure the quality and safety of their products by evaluating contamination, chemical composition of ingredients, and sensory properties of tea.
Challenge for producers & distributors of tea
For tea marketers, depending on the origin, various challenges can arise with regard to the ingredients and quality of the tea.
Pesticides
Tea can be contaminated by pesticides and other chemicals used during cultivation and processing. Tea manufacturers must ensure that their products are within the limits for pesticides and other chemicals to ensure the product safety of the tea.
Pyrrolizidine alkaloids
Pyrrolizidine alkaloids (PAs) are natural constituents of plants and may be present in some herbal teas and other teas. PAs can be toxic in higher doses and have the potential to cause liver damage and cancer. Some of the plants that contain PAs are Senecio, Crotalaria, Echium, Symphytum, and Heliotropium. Tea made from these plants may also contain PA.
Microbiological Testing
Microbiological contamination can be a problem with tea if tea leaves and products become contaminated with bacteria, molds or other microorganisms during processing or storage. Moisture and temperature conditions during storage and transportation can also promote the growth of microorganisms.
Certain microorganisms, such as Salmonella and Escherichia coli (E. coli), can cause illness when present in food.
To ensure that tea is free of microorganisms, microbiological analysis can be performed at Tentamus laboratories. Standard methods and guidelines are used to check for the presence of bacteria, molds and yeasts. Analyses include the determination of Salmonella, E. coli and other pathogenic microorganisms.
By analyzing tea for microbial contamination, tea manufacturers and retailers can ensure that their tea is safe, hygienic and meets regulatory requirements.
Anthraquinone
Anthraquinone is a process contaminant that can be produced during the manufacture of tea through the use of certain plant materials and production methods. Anthraquinone can remain in tea leaves and cause health problems at high concentrations.
The European Union has set a limit for anthraquinone in tea to ensure that it is safe for human consumption. However, in 2020, some teas, particularly those from China, were found to exceed the limit for anthraquinone. In response, the European Union has taken action to control the import of tea and ensure that it complies with the limit for anthraquinone.
Tea as a medicine
Tea used as a medicinal product is subject to particularly strict regulations and quality controls in accordance with the provisions of the European Pharmacopoeia (Ph. Eur.). The European Pharmacopoeia is a binding collection of standards and regulations for medicinal products and contains specific requirements for tea used as a medicine.
A special feature in the quality control of tea as a medicinal product is the determination of essential oils in tea. Essential oils are volatile aromatic compounds found in some teas and are responsible for the flavor and aroma of the tea. Determining the essential oils in tea is important to ensure that the tea has the required quality and potency for use as a medicine.
The European Pharmacopoeia regulations also contain requirements for the cultivation, harvesting, processing, and storage of tea as a medicine. These requirements are intended to ensure that the tea is free from contamination and impurities and that it is of the required quality and potency.
Tea as infant food
Tea used as infant food is subject to particularly stringent requirements regarding pesticides and other potentially harmful substances. The use of tea as infant food is widespread.In particular, fennel tea is often used to relieve flatulence and colic in infants.
In the European Union, there are specific regulations for tea as infant food, set out in Regulation (EC) No. 1881/2006. These regulations set maximum residue levels for pesticides, heavy metals and other contaminants in tea used as infant food.
Necessary tests for the analysis of tea
To ensure that tea is of high quality and safe for consumption, several investigations are necessary.
Residue Analysis
Tentamus laboratories offer residue analysis for tea, among other services, to ensure that tea is free of unwanted residues and contaminants and meets regulatory requirements.
- Pesticide analysis: Pesticide analysis for tea is performed in Tentamus laboratories according to international standards to ensure that the results are trustworthy and comparable. State-of-the-art analytical methods such as gas chromatography-mass spectrometry (GC-MS) and liquid chromatography-mass spectrometry (LC-MS) are used to reliably identify even the smallest traces of pesticides.
- Determination of polycyclic aromatic hydrocarbons (PAHs): PAHs are organic compounds formed when carbon is burned and can be harmful to health if consumed. PAHs can be found in tea that is roasted over an open fire. Analysis of PAHs in tea is important to ensure that the tea is free of unwanted contaminants.
- Determination of heavy metals: Heavy metals can be present in tea if the tea is grown in soil contaminated with heavy metals or comes into contact with materials containing heavy metals during processing. Heavy metals can be harmful to health if they accumulate in high concentrations in the body. Analysis of heavy metals in tea is important to ensure that tea complies with current regulations.
Chemical analyses
Chemical analyses are an important part of tea quality assurance to ensure that tea meets regulatory requirements. Chemical analyses can be performed in the Tentamus laboratories and include:
- Determination of caffeine: The amount of caffeine in tea can vary depending on the variety and origin. Analysis of caffeine in tea is important to ensure that the tea complies with current regulations and does not contain excessive amounts of caffeine.
- Determination of flavonoids: Flavonoids are natural compounds found in tea that may have beneficial health effects. Analysis of flavonoids in tea is important to prove that the tea is of high quality and contains a sufficient amount of healthy compounds.
- Analysis of catechins and total phenols: These are natural compounds found in tea that may have beneficial health effects. Catechins are a type of polyphenols and are responsible for the bitter taste and characteristic smell of tea. Total phenols are a group of compounds found in many plant foods and are known for their antioxidant activity.
The analysis of catechins and total phenols in tea is suitable to check the quality of tea.
By performing chemical analyses in Tentamus laboratories, tea producers and traders can ensure that their tea complies with current regulations.
Analysis of Origin
Tea origin analysis is an important method to verify the origin and quality of tea. The analysis is carried out by determining chemical markers that are characteristic of the geographical region where the tea was grown.
Origin analysis is particularly important for the protection of geographical indications (GIs). For example, analysis of chemical markers such as tea polyphenols, amino acids, and flavonoids can identify specific tea varieties such as Darjeeling, Assam, or Ceylon. These tea varieties have protected geographical designations of origin and may only come from certain regions of India and Sri Lanka.
Origin analysis can also help prevent fraud. It can ensure that the tea actually comes from the specified region and has been labeled correctly. This can uncover cases of food fraud, where higher-quality tea is mixed with a lower-quality tea to increase margins.
Origin analysis can help prevent such cases. The Tentamus Group laboratories offer origin analysis for tea samples to comply with applicable regulations and ensure high quality.
Labeling
Tea labeling verification is an important step in ensuring that tea meets regulatory requirements and is declared correctly. Tea labeling includes information such as
- the name of the product
- the list of ingredients
- the best before date
- the net quantity
- special instructions, if any, such as allergens
- special instructions for preparation
A label check verifies that all required information is present and correctly stated. For example, the ingredient list must include all ingredients contained in the tea, including added flavors and other additives.
Appropriate labeling tests for tea packaging can be performed at Tentamus laboratories.
Sample shipment
for tea analysis
If you would like to have a tea analysis performed at one of our Tentamus laboratories, please note the following points for sample collection and shipment:
- Sampling: collect a representative sample that is a good representation of the tea or tea production batch. Be sure to use clean and dry containers for sampling to avoid contamination.
- Sample packaging: pack the sample securely in appropriate packaging that protects the sample from moisture, light exposure, and damage.
- Shipping: use a reliable and fast shipping service so that your sample arrives quickly and safely at Tentamus Laboratories. Be aware of shipping requirements and required documents, such as customs documentation for international shipments.
You are also welcome to hire us for an accredited sample collection or to collect the sample.
Simply contact us to arrange an appointment and our competent logistics team will take care of the rest.
Relevant legal bases & directives
- Regulation (EC) No. 396/2005 of the European Parliament and of the Council (maximum levels of pesticide residues).
- Commission Regulation (EU) No. 2023/915 (contaminants in food) (consolidated text).
- Regulation (EU) No. 2018/848 of the European Parliament and of the Council (organic products)
- Regulation (EU) No. 1169/2011 of the European Parliament and of the Council (Food Information Regulation)
Get in touch with our team:
food@tentamus.com
+49 30 206 038 230
Overview of
laboratories offering analysis of tea
The following laboratories from the Tentamus Group offer analysis of tea
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