Green Tea PhD - Glossary

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Antioxidant

Catechins

Enzyme

Flavonoids

Oxidation

Polyphenols

Tannins

Theanine

Tea Bowl

Tea Caddy

Tea Cups

Tea Jar

Tea Scoop

Teapot

Tea whisk

Antioxidant - An antioxidant is a chemical that prevents the oxidation of other chemicals in the body. In biological systems, the process of oxidation produces highly reactive free radicals. These free radicals readily react with other molecules causing damage to them. In some cases the body uses this reaction to fight infection. In other cases, the damage may be to the body's own cells. Only green tea retains its powerful antioxidant properties.

Catechins - Catechins are a category of polyphenols. In green tea, catechins are present in significant quantities, more specifically; epicatechin (EC), epigallocatechin (EGC), epicatechin gallate (ECG) and epigallocatechin gallate (EGCG). EGCG is the most powerful catechins, making up about 10-50% of the total catechin content. The antioxidant activity about 25-100 times more potent than vitamins C and E. One cup of green tea may provide 10-40mg of polyphenols and can have an antioxidant activity greater than a serving of broccoli, spinach, carrots or strawberries. A catechin is effective because it sticks to proteins easily and blocks bacteria from adhering to cell walls. This disrupts their ability to destroy them. The catechin in green tea also prevents viruses from adhering to cell walls and causing harm.

Enzyme - Enzymes are a protein that catalyzes, or speeds up, a chemical reaction. Enzymes are essential to sustain life because most chemical reactions in biological cells would occur too slowly, or would lead to different products, without enzymes.

Flavonoids - Flavonoids are plant pigments, or brightly colored chemical elements found in most fresh fruits and vegetables. Flavonoids are chemicals that occur naturally in plants. A simple definition describes flavonoids as "any group of substances found in fruits and vegetables essential for processing vitamin C and needed to maintain capillary walls. They are important antioxidants in the diet. They have been shown to boost immunity, help with the maintenance, protect against infection and proper functioning of blood vessels, and in one study to slow the growth of cancer.

Oxidation - Substances that have the ability to oxidize other substances are said to be oxidative and are known as oxidizing agents, oxidants or oxidizers. The oxidant removes electrons from the other substance, and is thus reduced itself. Oxidation in tea leaves is produced by exposure to the air. However, green tea is produced by lightly steaming the fresh-cut leaf, which inactivates these enzymes, and oxidation does not occur. This allows green tea to maintain its possible healing abilities through antioxidants

Polyphenols - Polyphenols are a class of phytochemicals. Phytochemicals are to be any chemical or nutrient derived from a plant source and have a beneficial effect on health or an active role in the amelioration of disease. These are found in high concentrations in green tea, and have been associated with heart disease and cancer prevention. The slight astringent, bitter taste of green tea is attributed to polyphenols.

Ro Nien - kneading and rolling; the fifth stage of production

Tannins - A group of simple and complex phenol, polyphenol, and flavonoid compounds, bound with starches. They are often so amorphous that they are classified as tannins simply because they reach a point in degradation where they are astringent and contain variations on gallic acid. Tannins are produced by plants and are generally protective substances found in the outer and inner tissues. All of the tannins are relatively resistant to digestion or fermentation, and either decrease the ability of animals to easily consume the living plant, or cause shed parts of the plant to decay so slowly that there reduces the likelihood of infection to the living tree from rotting dead material around its base. All tannins act as astringents, shrinking tissues and contracting structural proteins in the skin and mucus.

Tea bowl – A tea bowl is specifically used to make matcha tea in traditional Japanese tea ceremonies. There are two types; a flatter open shaped bowl for summer and one with vertical walls and a thicker lip used in the winter. They are usually identified by their shape or type of ceramic ware. The shapes vary from cylindrical, flat or shoe-like. They types of ceramic ware include Raku, Hagi, Shino, Oribe and Karatsu.

Tea caddy –Also called the Cha-ire, this utensil is used to keep tea leaves fresh. They are round in shape and vary in size. The have a flat inner lid, made of metal, with a knob beneath the decorative outer lid. This knob helps keeps the moisture out. Alternative styles made of paper are also available.

Tea cups – The size of the teacup varies depending on the type of tea being served; teas such as sencha and Gyokuro are best enjoyed from a smaller cup while bancha easy to drink and can be served in a larger cup. Regardless of cup size, a white interior is recommended so the color can be seen.

Tea Jar – This is decorative jar that hold matcha tea during Japanese tea ceremonies. This is different than a tea caddy because of its shape. It resembles the fruit of the natsume or Chinese date tree. It is made from lacquered bamboo, wood or even paper. The way one arranges of the mound of matcha in the tea jar is part of the art of the tea ceremony.

Tea scoop – This is a spoon like utensil made of bamboo, wood or metal used to measure the amount of leaves to be poured from the tea caddy to tea pot. A larger scoop called a chago is used for sencha tea ceremony. It is often decorated with literary scenes.
For Japanese tea ceremonies, the scoop is made of bamboo, ivory or wood. It is slender and 17 inches in length. It possibly originated from the medicinal spoons of the Chinese Sung Dynasty.

Teapot - The teapot is the most important utensil to choose. Getting the right size is crucial for particular tea types. Heating the pot before use is also recommended. A pot with a rounded bottom allows the tea leaves and water to circulate freely, enriching the flavor of the tea.

Tea whisk – This is a bamboo whisk used to whip matcha into a frothy consistency for Japanese tea ceremonies. Matcha is a fine powdered tea that does not dissolve but must be whipped into a foamy substance. The whisk contains an outer circle and an inner loop that blends the water and powdered tea

Theanine - An amino acid that produces tranquilizing effects in the brain. Theanine is a unique amino acid found in the leaves of green tea. It is quite different from the polyphenol and catechin antioxidants for which green tea is typically consumed. Natural production of polyphenols in the tea plant converts theanine into catechins. This means that tea leaves harvested during one part of the growing season may be high in catechins, known for their antioxidant benefits, while leaves harvested during another time of year may be higher in theanine which is good for anti-stress and cortisol-controlling effects. Three to four cups of green tea are expected to contain 100-200 mg of theanine.

Wei Diao - Withering; the second stage of production (Chinese terminology for production)