Tea, scientifically known as Camellia sinensis, is recognized as one of the most popular genera in the flowering shrubs with the profusion and beauty of the garden varieties. It is the second most commonly drank liquid after water. All the tea is made from this species, and it is grown mainly in the plantations in highlands of tropical Asia. It originated from southern China, then spread to Japan and India and more recently in other parts of the world where the climate is suitably mild and humid. It was introduced into European countries by Portuguese and Dutch explorers as a medicinal herb because it is the oldest known medicine. Tea consumption was dated back to 3000 BC, and it is found to have plenty of beneficial effects on human health.
Tea tree is usually six to ten feet tall with thin and serrated leaves. It is a flowering bushes with white to cream with a hint of lemon flowers, which are about one inch in size across borne on recurved stalks from the leaf axils. However, the flowers are relatively insignificant as the leaves are the parts that are being used and consumed. The juvenile or young shoots are the most significant part, which the serrated leaves are observed. The shrub has tender new shoots that are usually plucked, fermented, and dried in different ways to give black or green tea. Growing tea tree is easy by planting them at the highland with high humidity. They are usually trimmed to about breast height. Nowadays, Camellia sinensis var. assamica is the Assam tea with larger leaves with more vigorous growth in India and Sri Lanka.
Tea can be categorized into six types: green tea, yellow tea, white tea, oolong tea, black tea, and dark tea based on their appearance, organoleptic taste, chemical contents, and flavor as a result of fermentation. Green tea is the most popular and oldest type of unfermented tea that has been enjoyed in China for several millenniums. It tastes better in fresh by giving a sweet taste after the bitter taste. It is made by processing and drying the new and young shoots of the tea shrub according to the recipe for making the desired tea. Generally, to process an excellent green tea needs three significant processes. First, the drying process must be conducted before any steps. Then, dehydration is essential to remove the excess water content. It is then followed by rolling traditionally in a wok to “stir fry” the tea leaves without any oil or solutions. Lastly, drying is the final step and crucial to ensuring the tea leaves had removed all their water content. Removal of water content is to ensure there is no problem with storage for an extended period. Otherwise, fungal growth will be observed resulted in spoilage of the grade of the tea. Green tea is scientifically known as the tea consisting of the highest antioxidant contents because it is un-wilted and unoxidized tea among all the teas. However, it contains lesser caffeine compared to black tea.
Then, uncured green tea that has not undergone fermentation is categorized as white tea used the young buds, which were collected shortly after the buds have fully opened. It has been steamed and dried quickly, resulting in the lowest levels of caffeine than any other teas. The characteristics of white tea are that the tea produces lighter color than any other teas and gives a delicate flavor. Moreover, yellow tea is produced by drying damp tea leaves naturally. Thus, producing a distinctive aroma that is similar to the red tea. However, yellow tea is much closer to green and white tea in term of flavor. Due to its yellow color in nature, it is known and used to describe the high-quality tea served to emperors in China in ancient times.
Blue tea, also known as oolong tea is a partially fermented tea with particular characteristics. The unique trait is made from a blend of green and red tea that boost the best flavors and aromatic qualities. Therefore, it has the name “green leaves with a red edge”. It is a popular tea to decompose fat, making it a great beauty enhancer and weight loss healthy drink. Next, the most popular tea flavored by the British is black tea or popularly called red tea. It is made by using the wilted, rolled, and dried new shoots. The infusion resulted in red color with a subtle aromatic fragrance that gives it red tea. This is because it has a dark color that is nearly black but gave a red infusion in water. The black tea undergoes longer fermentation than green tea, giving a distinct flavor that may require sugar or milk. Therefore, it has the most caffeine compared to green tea.
Dark tea is a post-fermented tea which has fermented the most that involved bacteria. The basic processes mentioned earlier have different procedures: water removal, first rolling, heaping, second rolling, baking, and drying. From there, it further developed into Pu’er tea that is compressed into a brick tea. Finally, it is a fully oxidized tea in which it has a lower antioxidant content than any other teas, in which it has three to four percent polyphenols, which is relatively low compared to thirty to forty percent found in green tea.
The degree of fermentation of the teas are arranged in the following ascending order:
Green tea < White Tea < Yellow tea < Oolong tea < Black Tea < Dark tea
The definition of fermentation is a metabolic process that involved changes in organic substrates with the aid of enzymes.
However, the classification of the types of tea in China and western countries are different. In western countries, the names of the teas are directly referring to the color of the leaves after they are being processed, which are either black or green. On the other hand, their names in China are reflected by the color of the brew. For instance, red tea in China is the black tea leaves that produced a red color when it is brewed. On top of that, black tea in the West usually refers to the tea served in the absence of milk, whereas white tea is commonly known as milk tea, which is the black tea that is added with milk.
In Chinese and Japanese culture, drinking tea is a common practice, which can be practiced for any event. However, in western culture, one must know what kinds of tea party it is hosting. For instance, high tea, which is commonly assumed as fancy tea, is wrong. Instead, high tea is a tea party that served substantive fare like meat, fish, and egg dishes as well as desserts and bread that usually held in the early evening around five to seven o’clock. High tea could be a light supper served with a tea using a high table, a dining table. Specifically, high tea is usually prepared for the laborers who would arrive home from their physically demanding jobs and worked hard all day long.
On the other hand, a tea party that includes only scones, sandwiches, and cakes is considered as afternoon tea served in mid-afternoon. Afternoon tea is also known as low tea, which refer to the height of the table, which is a low coffee table. It is a social afternoon meal or social tea that is not sustainable for a working-class laborer. In British tradition, it is often held by a group of leisure-loving ladies of the upper classes who enjoy the treat rather than a regular meal. The significant difference between high and low tea is the symbolic of them in which high tea is for labor or working people, whereas low tea is served for non-working classes or upper-class people. Therefore, one must be putting extra precautions like inviting someone for a tea party and use the correct height of the table. Commonly, the tea served in low tea is Earl Grey or English Breakfast tea, which is robust black teas.
The active compounds that have been found in tea is nearly four thousand bioactive compounds, primary polyphenols such as catechins and flavonoids, alkaloids like caffeine, theobromine, theophylline, volatile oils, polysaccharides, amino acids, lipids, vitamins that include vitamin C and E, inorganic elements that consists of aluminium, fluorine, and manganese and so on. It is proven that the mentioned compounds are the primary compounds that are responsible for the benefits to human health. The critical compound that focused the most is catechin, which is further categorized into catechin, gall catechin, epicatechin, epigallocatechin, epicatechin gallate, and epigallocatechin gallate. It is found that catechins also found naturally in black tea, coffee, berries, grapes, and wine.
Several properties like antioxidant activity, anti-inflammatory, anti-allergic properties, and anti-microbial effects are observed in flavonoids. The American Medical Association mentioned that the active compounds present in green tea could help lower cholesterol and blood sugar levels, high blood pressure, and the chances to get strokes, especially in males. The National Cancer Institute also reported that high antioxidant level in green tea aid in digestion, purification of blood, bone and teeth strengthening, lowering body temperature, enhance the function of our heart, suppress ageing that is related to Parkinson’s and Alzheimer’s diseases, and boost the immune system. There are hydroxyl hydrogens of the polyphenols are involved in ending the excessive free radicals chain reaction. Such antioxidant activity helped reduce the concentration of free radicals and indirectly reduce the risk and chance of getting cancer. Generally, it is good at detoxifying and improves resistance to many diseases with the high antioxidant activity.
The volatile organic compounds, which are ready to be vaporized and contribute to the wonderful tea aroma. Due to their high contents and beneficial properties, they are often extracted and commercialized into various downstream products. One of the most common products is green tea packed into teabags or processed into powdered form and facial and cosmetic products. Matcha is the most popular green tea product of Japanese green tea of the Tencha variety. Matcha powder is commonly found to be added into various food products, especially drinks, desserts, and bakery, due to its dark green color. Many research supported that the green tea extract, which is consumed orally or applied to the skin, was able to inhibit the formation of tumor on the skin induced by ultraviolet light and possesses anti-inflammatory trait apart from anti-aging property.
Caffeine is another essential component of tea apart from different types of catechins. Different caffeine concentrations are found different, which are strongly dependent on the variety of the tea, weather conditions during propagation and vegetation, and the brewing method. High caffeine content is found from matcha compared to other green teas, which gives it a unique aroma and flavor. Generally, the caffeine content of the tea is higher than that of coffee. The caffeine content in green tea is found around 11.3 – 24.67 mg/g, while the range of the caffeine in matcha is about 11.3 – 24.67 mg/g. However, most coffee beans consist of 10.0 – 12.0 mg/g of beans. To maximize the benefits of tea, there are various ways to make a cup of tea.
Kombucha is a fermented drink that used sugared tea as a starter media with a symbiotic culture of acetic bacteria and yeast, which is called SCOBY in short. It is usually called mushroom tea or tea fungus. This drink is mainly consumed for its beneficial effects on human health. This fermented drink tasting like sparkling apple cider can be made at home, and infinite possibilities can be done by having second fermentation using species, herbs, vegetables, and fruits as an additive or natural flavoring. The best starting tea for kombucha is black tea with white sugar, although other teas like green tea can be used. With a large amount of information studied and published concerning the beneficial effects of tea and its major constituents on human health, kombucha is believed as the healthy and refreshing beverage with plenty of benefits. Kombucha is healthy, especially when it is appropriately made since it is a probiotic-rich tea with many potential health benefits found in black tea. The taste combine with some spices, herbs, vegetables, or fruits blend to have fruity second fermentation.
When tea is combined with milk, it become the most popular drink, known as milk tea. Due to the presence of the tannins in the tea, people add a sweetener like condensed milk occasionally and lemon juice to enhance its taste. There are several types of milk tea: classic cuppa, Hokkaido milk tea, Okinawa milk tea, boba (bubble tea), Hong Kong milk tea, masala chai, Thai tea, and tea lattes.
A traditional breakfast blend such as Irish breakfast and English breakfast is generally referred to as a classic cuppa. The British usually prepare their tea with milk or sometimes sweetener. In addition, the milk teas that are originated from Japan are Hokkaido and Okinawa milk tea that used black teas. The difference between Hokkaido and Okinawa milk tea is that Hokkaido milk tea used only the milk from Hokkaido that is always followed with honey, caramel, or brown sugar, whereas Okinawa milk tea was blended with milk and Okinawa brown sugar. Okinawa brown sugar is slightly different from ordinary brown sugar, which is called kokuto, which is made by reducing pure sugarcane juice, which has a complex and nuanced flavor with high mineral contents.
Boba, the most popular unique milky tea added with tapioca pearls originating from Taiwan, is typically bubble tea. It is famous for customizing the ice, sweetness, flavors from classic black tea to fruit, floral, or sweet concoctions. In Hong Kong, milk tea is made using black tea, specifically Ceylon or aged tea like Pu-erh and evaporated milk or sweetened condensed milk. The leaves are filtered using a filter funnel that is made up of cloth. Therefore, Hong Kong milk tea is also known as panty-hose milk tea due to the cloth-based filter.
Masala chai, which is found in India in the late nineteenth and early twentieth centuries, is made using black tea with some traditional Indian spices steeped in steamed milk or by adding milk to a cup of traditionally prepared tea. Thai tea from its name we know it is coming from Thailand. It usually served with ice that has a base of Assam or Ceylon. It can be further flavored by adding mint, lime, orange blossoms, star anise, tamarind, and other spices. Lastly, tea lattes that are now typically seen in most coffee shops and cafes used to expand their tea selection and served as an alternative for the customers who may prefer tea over coffee. Tea lattes are made of tea and steamed as well as frothed milk.
The list of different tea consuming habits goes on and on. When was your last cup of tea, how and what you prepare your tea recipe or party? Feel free to share in the comments!
Further readings:
Smith, B. G., Burgess, P. J., & Carr, M. K. V. (1994). Effects of clone and irrigation on the stomatal conductance and photosynthetic rate of tea (Camellia sinensis). Experimental Agriculture, 30(1), 1-16.
Tijburg, L. B. M., Mattern, T., Folts, J. D., Weisgerber, U. M., & Katan, M. B. (1997). Tea flavonoids and cardiovascular diseases: a review. Critical Reviews in Food Science & Nutrition, 37(8), 771-785.
Dufresne, C., & Farnworth, E. (2000). Tea, Kombucha, and health: a review. Food research international, 33(6), 409-421.
Cabrera, C., Artacho, R., & Giménez, R. (2006). Beneficial effects of green tea—a review. Journal of the American College of Nutrition, 25(2), 79-99.
Gardner, E. J., Ruxton, C. H. S., & Leeds, A. R. (2007). Black tea–helpful or harmful? A review of the evidence. European journal of clinical nutrition, 61(1), 3-18.
Sharangi, A. B. (2009). Medicinal and therapeutic potentialities of tea (Camellia sinensis L.)–A review. Food Research International, 42(5-6), 529-535.
Namita, P., Mukesh, R., & Vijay, K. J. (2012). Camellia sinensis (green tea): a review. Global journal of pharmacology, 6(2), 52-59.
Senanayake, S. N. (2013). Green tea extract: Chemistry, antioxidant properties and food applications–A review. Journal of functional foods, 5(4), 1529-1541.
Musial, C., Kuban-Jankowska, A., & Gorska-Ponikowska, M. (2020). Beneficial properties of green tea catechins. International journal of molecular sciences, 21(5), 1744.
Engelhardt, U. H. (2020). Tea chemistry–What do and what don’t we know?–A micro review. Food Research International, 132, 109120.
Kochman, J., Jakubczyk, K., Antoniewicz, J., Mruk, H., & Janda, K. (2021). Health Benefits and Chemical Composition of Matcha Green Tea: A Review. Molecules, 26(1), 85.
