'A HISTORY OF...'//TEA//OUGD504-SUMMER

TEA:

Tea is an aromatic beverage commonly prepared by pouring boiling hot water over cured leaves of the Camellia sinensis plant. The term also refers to the plant itself. After water, tea is the most widely consumed beverage in the world. It has a cooling, slightly bitter, astringent flavour which many people enjoy.

Consumption of tea (especially green) is beneficial to health and longevity given its antioxidant, flavanols, flavonoids, polyphenols, and catechins content. Tea catechins have known anti-inflammatory and neuroprotective activities, help to regulate food intake, and have an affinity for cannabinoid receptors, which may suppress pain, nausea, and provide calming effects.

Consumption of green tea is associated with a lower risk of diseases that cause functional disability, such as “stroke, cognitive impairment, and osteoporosis” in the elderly.

Tea contains L-theanine, and its consumption is strongly associated with a calm but alert and focused, relatively productive (alpha wave dominant), mental state in humans. This mental state is also common to meditative practice.

The phrase herbal tea usually refers to infusions of fruit or herbs made without the tea plant, such as rosehip tea or chamomile tea. Alternative phrases for this are tisane or herbal infusion, both bearing an implied contrast with "tea" as it is construed here.

CULTIVATION AND HARVESTING:

Camellia sinensis is an evergreen plant that grows mainly in tropical and sub-tropical climates. Some varieties can also tolerate marine climates and are cultivated as far north as Pembrokeshire in the British mainland and Washington in the United States.

Tea plants are propagated from seed or by cutting; it takes approximately 4 to 12 years for a tea plant to bear seed, and about 3 years before a new plant is ready for harvesting. In addition to a zone 8 climate or warmer, tea plants require at least 127 cm. (50 inches) of rainfall a year and prefer acidic soils. Many high-quality tea plants are cultivated at elevations of up to 1,500 metres (4,900 ft): at these heights, the plants grow more slowly and acquire a better flavour.

Only the top 1-2 inches of the mature plant are picked. These buds and leaves are called flushes. A plant will grow a new flush every seven to fifteen days during the growing season, and leaves that are slow in development always produce better flavored teas.

A tea plant will grow into a tree of up to 16 metres (52 ft) if left undisturbed, but cultivated plants are pruned to waist height for ease of plucking.

Two principal varieties are used: the China plant (C. sinensis sinensis), used for most Chinese, Formosan and Japanese teas (but notPu-erh); and the clonal Assam tea plant (C. sinensis assamica), used in most Indian and other teas (but not Darjeeling). Within these botanical varieties, there are many strains and modern Indian clonal varieties. Leaf size is the chief criterion for the classification of tea plants, with three primary classifications being: Assam type, characterized by the largest leaves; China type, characterized by the smallest leaves; and Cambod, characterized by leaves of intermediate size.

PROCESSING AND CLASSIFICATION:

Teas can generally be divided into categories based on how they are processed. There are at least six different types of tea: white,yellow, green, oolong, black, and post-fermented teas of which the most commonly found on the market are white, green, oolong, and black. Some varieties, such as traditional oolong tea and Pu-erh tea, a post-fermented tea, can be used medicinally.

After picking, the leaves of Camellia sinensis soon begin to wilt and oxidize, unless they are immediately dried. The leaves turn progressively darker as their chlorophyll breaks down and tannins are released. This enzymatic oxidation process, known asfermentation in the tea industry, is caused by the plant's intracellular enzymes and causes the tea to darken. In tea processing, the darkening is stopped at a predetermined stage by heating, which deactivates the enzymes responsible. In the production of black teas, the halting of oxidization by heating is carried out simultaneously with drying.  Without careful moisture and temperature control during manufacture and packaging, the tea may become unfit for consumption, due to the growth of undesired molds and bacteria. At minimum it may alter the taste and make it undesirable.

Tea is traditionally classified based on the techniques with which it is produced and processed.

• White tea: Wilted and unoxidized
• Yellow tea: Unwilted and unoxidized, but allowed to yellow
• Green tea: Unwilted and unoxidized
• Oolong: Wilted, bruised, and partially oxidized
• Black tea: Wilted, sometimes crushed, and fully oxidized
• Post-fermented tea: Green tea that has been allowed to ferment/compost

BLENDING AND ADDITIVES

Although single estate teas are available, almost all teas in bags and most other teas sold in the West are blends. Blending may occur in the tea-planting area (as in the case of Assam), or teas from many areas may be blended. The aim of blending is to obtain better taste, higher price, or both, as a more expensive, better-tasting tea may cover the inferior taste of cheaper varieties.

Some teas are not pure varieties, but have been enhanced through additives or special processing. Tea is highly receptive to inclusion of various aromas; this may cause problems in processing, transportation, and storage, but also allows for the design of an almost endless range of scented and flavored variants, such as bergamot (Earl Grey), vanilla, caramel, and many others.

CONTENT

Tea contains catechins, a type of antioxidant. In a freshly picked tea leaf, catechins can compose up to 30% of the dry weight. Catechins are highest in concentration in white and green teas, while black tea has substantially fewer due to its oxidative preparation. Research by the U.S. Department of Agriculture has suggested that levels of antioxidants in green and black tea do not differ greatly, as green tea has an oxygen radical absorbance capacity (ORAC) of 1253 and black tea an ORAC of 1128.

ORIGIN AND HISTORY

Tea plants are native to East and South Asia and probably originated around the point of confluence of the lands of northeast India, north Myanmar and southwest China.

Although there are tales of tea's first use as a beverage, no one is sure of its exact origins. The first recorded drinking of tea is in China, with the earliest records of tea consumption dating back to the 10th century BC. It was already a common drink during the Qin Dynasty (3rd century BC) and became widely popular during the Tang Dynasty, when it was spread to Korea and Japan. Trade of tea by the Chinese to Western nations in the 19th century spread tea and the tea plant to numerous locations around the world.

Tea was imported to Europe during the Portuguese expansion of the 16th century, at which time it was termed chá. In 1750, tea experts traveled from China to the Azores Islands, and planted tea, along with jasmines and mallows, to give the tea aroma and distinction. Both green tea and black tea continue to grow in the islands, which are the main suppliers to continental Portugal. Catherine of Braganza, wife of Charles II, took the tea habit to Great Britain around 1660, but it was not until the 19th century that tea became as widely consumed in Britain as it is today. In Ireland, tea had become an everyday beverage for all levels of society by the late 19th century, but it was first consumed as a luxury item on special occasion such as religious festivals, wakes, and domestic work gatherings such as quiltings.

wikipedia

FOUR MAIN VARIETIES OF TEA:

BLACK TEAS

-Black teas get their characteristic flavour and colour from a natural oxidation process, which follows initial drying and rolling of the leaves after they have been picked.

GREEN TEAS

-Green tea is made from unoxidized leaves which are simply heated after picking to destroy the enzymes that cause oxidation. They are then rolled to release their flavour. Green teas are sweet and contain many of the vitamins and antioxidant properties of the fresh green tea leaf, making them highly regarded as a healthy, fragrant and delicious drink.

OOLONG TEAS
-Oolong, meaning Black Dragon, is usually from China and Taiwan (often called Formosa, its old Portuguese name). It is a semi-fermented tea, a cross between green and black teas, which is widely prized for its digestive benefits.
WHITE TEAS
-White tea is the world's rarest tea as it can only be picked for a few weeks in any one year. Authentic white tea is only grown in the Fujian province in China where the exact method of processing is kept secret. What we do know is that white tea is made from a specific tea plant variety, as well as a particular processing method which raises small silvery hairs on the leaves and buds.
White tea has seen a recent increase in popularity and has well-documented antioxidant and detoxifying benefits.

http://www.teapalace.co.uk/Different-Types-of-Tea-Adifferent/

BLACK TEAS:

Black tea is a type of tea that is more oxidized than oolong, green and white teas. All four types are made from leaves of the shrub (or small tree) Camellia sinensis. Black tea is generally stronger in flavor than the less oxidized teas. Two principal varieties of the species are used – the small-leaved Chinese variety plant (C. sinensis subsp. sinensis), used for most other types of teas, and the large-leaved Assamese plant (C. sinensis subsp. assamica), which was traditionally mainly used for black tea, although in recent years some green and white have been produced.

In Chinese languages and the languages of neighboring countries, black tea is known as "red tea" (紅茶, Mandarin Chinese hóngchá;Japanese kōcha; 홍차, Korean hongcha), a description of the colour of the liquid; the Western term "black tea" refers to the colour of the oxidized leaves. In Chinese, "black tea" is a commonly-used classification for post-fermented teas, such as Pu-erh tea; outside of China and its neighbouring countries, "red tea" more commonly refers to rooibos, a South African tisane.

While green tea usually loses its flavor within a year, black tea retains its flavour for several years. For this reason, it has long been an article of trade, and compressed bricks of black tea even served as a form of de facto currency in Mongolia, Tibet and Siberia into the 19th century. Although green tea has recently seen a revival due to its purported health benefits, black tea still accounts for over ninety percent of all tea sold in the West.

NINE HEALTH BENEFITS OF BLACK TEA:

Today, India, China, and Sri Lanka are the world's largest producers of black tea. In the production of black tea, the leaves are first spread out on racks and blown with air to remove about a third of their moisture and make them pliable. Then they are rolled around to break their cell walls and release the sugars necessary for fermentation. To promote fermentation they are kept in a highly humid environment, which turns the leaves dark and develops black tea's strong flavor. Finally, the leaves are dried and shipped off to all corners of the globe. The health benefits of black tea focus on the same areas as the green, oolong, and white variety. Since they all come from the same plant, it's only natural they would have similar benefits.

ONE:

Cardiovascular Health

Black tea is abundant in antioxidants, such as flavonoids, demonstrated to prevent the oxidation of LDL cholesterol, preventing damage in both the bloodstream and at artery walls, and lowering the risk of heart disease. Additionally, it has been shown that black tea flavonoids are able to both improve coronary vasodilation and reduce clots. Polypehnols found in black tea are also very strong antioxidants, and the manganese in black tea may reduce the risk of coronary heart disease by helping cardiac muscle function.

TWO:

Cancer Prevention
Polyphenols in tea seem to help in preventing formation of potential carcinogens in the body, particularly in certain types of cancer, such as ovarian, lung, prostate, colorectal, and bladder. Other studies reveal that black tea may help prevent stomach, prostate, and breast cancer. A compound in black tea called TF-2 causes such cancer cells to go into apoptosis (programmed cell death) while normal cells remain unaffected. One study on oral cancer showed that consuming black tea can significantly reduce the risk of oral cancer, particularly in those who smoke cigarettes and use other tobacco products.
THREE:
Skin and Hair Health
The antioxidants in green tea may help keep your skin from being plagued by acne, and in some cases have been demonstrated to function equally as well as the harsher benzoyl peroxide used in so many skin products.
FOUR:
Bone and Connective Tissue
Studies indicate that the bones of regular tea drinkers are stronger than those of non-tea drinkers, even when other variables were adjusted for. Scientists theorize it may be an effect of the powerful tea's phytochemicals
FIVE:
Digestive Tract Health
The tannins in tea have a therapeutic effect on gastric and intestinal illnesses and make it a great digestive aid, used in China as such for thousands of years. These tannins decrease intestinal activity and exercise an antidiarrheal effect. The polyphenols in green tea have been demonstrated to have an effect on intestinal inflammation suffered by people afflicted with conditions like irritable bowel syndrome.
SIX:
Brain and Nervous System
Unlike high levels of caffeine found in coffee, the low amounts in black tea promote blood flow in the brain without over stimulating the heart. The caffeine in black tea hones mental focus and concentration and studies show that the amino acid L-theanine found in black tea can help you relax and concentrate more fully on tasks. Black tea has been shown to reduce levels of the stress hormone cortisol after a month of drinking four cups of tea daily. The caffeine in black tea might also give your memory the boost it needs for a few hours and some studies suggest that a regular tea habit may help protect against Parkinson's disease.
SEVEN:
Increased Energy
In moderation caffeine can be a benefit - in black tea it stimulates the metabolism, increases brain function and aids alertness. The caffeine in tea acts as more of a subtle stimulant, taking more than a few minutes to take effect, rather than hitting your system as quickly as coffee or cola. This effect is assisted by another compound found only in tea, theophylline. While caffeine chiefly targets the brain and muscles, theophylline stimulates the respiratory system, heart and kidneys. This helps maintain a healthy cardiovascular system.
EIGHT:
Oral Health
Research suggests that catechin antioxidants in black tea may reduce oral cancers. Tea's polyphenols and tannin perform as antibiotics, preventing bacteria that cause tooth decay, and the polyphenols in tea can help to keep in check the bacteria that cause bad breath.
NINE:
Immune System
Tea is full of substances called "tannins," which studies have shown have the ability to fight viruses such as influenza, dysentery and hepatitis. One such tannin named "catechin" helps suppress tumors. Black tea also contains alkylamine antigens, which help boost immune response. 

OOLONG TEA:

Oolong (simplified Chinese: 乌龙; traditional Chinese: 烏龍; pinyin: wūlóng) is a traditional Chinese tea (Camellia sinensis) produced through a unique process including withering under the strong sun and oxidation before curling and twisting. Most oolong teas, especially those of fine quality, involve unique tea plant cultivars that are exclusively used for particular varieties. The degree of fermentation can range from 8% to 85%, depending on the variety and production style. This tea category is especially popular with tea connoisseurs of south China and Chinese expatriates in Southeast Asia, as is the tea preparation process that originated from this area: gongfu tea-making, or the gongfu tea infusion approach.

In Chinese tea culture, semi-oxidised oolong teas are collectively grouped as qīngchá (Chinese: 青茶; literally "teal tea"). The taste of oolong ranges hugely amongst various subvarieties. It can be sweet and fruity with honey aromas, or woody and thick with roasted aromas, or green and fresh with bouquet aromas, all depending on the horticulture and style of production. Several subvarieties of oolong, including those produced in the Wuyi Mountains of northern Fujian and in the central mountains of Taiwan, are among the most famous Chinese teas.

Different varieties of oolong are processed differently, but the leaves are formed into one of two distinct styles. Some are rolled into long curly leaves, while others are 'wrap-curled' into small beads, each with a tail. The former style is the more traditional of the two.

The name oolong tea came into the English language from the Chinese name (Chinese: 烏龍茶), meaning "black dragon tea".

OOLONG TEA HEALTH BENEFITS:

• Enjoying oolong tea health benefits is as simple as brewing a few cups throughout the day. In fact, try replacing your morning coffee and mid-day soda with a cup of oolong. Then enjoy a cup of oolong tea an hour before bedtime and take advantage of the many oolong tea heath benefits and see how much better you feel. 
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• Weight Loss: One of the most popular oolong tea health benefits is weight loss. Oolong tea has been shown to increase your metabolism, increase fat burning and block the absorption of fat into the intestines. These factors come together to help you lose unwanted fat.
• Keep in mind however that an oolong tea regimen alone will probably not help you reach your weight loss goals, but when combined with a well balanced diet and regular exercise you can experience a boost to your fat loss efforts.
• Blood Pressure: Another oolong tea health benefit is it heart health properties. Adding a few cups of oolong tea to your diet can reduce the build-up of bad cholesterol as well as the concentration of fat in the body, particularly in the midsection.
• Oolong tea can also help decrease high blood pressure, which is a key element to successful weight loss. Because high blood pressure forces your heart to work too hard to be sustainable, this is one oolong tea health benefit anyone looking to lose weight can use. Several studies have shown that 2 cups of oolong tea can greatly reduce your risk of high blood pressure.
• Healthy Teeth & Bones: I know you’re probably thinking that weight loss has very little to do with your teeth and bones, but the truth is that weak bones and unhealthy teeth can lead to many health problems that can negatively impact weight loss efforts. The good news is that antioxidants in oolong tea can protect and improve the strength of your teeth and bones.
• Healthy bones means less injuries, which means you have more healthy days to get out there and burn fat through exercise and other physical activities. This may not be the oolong tea health benefits you were looking for, but healthy teeth brightens any smile and strong bones give you an upright posture that exudes confidence.
• Energy: Caffeine gives you more oolong tea health benefits in the form of a much-needed energy boost. Sure, your morning cup of java does have caffeine but with added cream and sugar the energy you get is more likely a sugar high that will cause an energy crash a couple hours later.
• The health benefits from drinking oolong tea however are far more than those associated with a cup of coffee. So while you may want that hot cup of coffee for energy, your weight loss and mood would prefer a cup of oolong tea instead.
• De-stressor: Drinking oolong tea is a great way to de-stress after a long day. With an oolong tea regimen you’re less likely to indulge in high calorie vices like junk food, soda and alcohol to make you feel better. In fact, when you feel as though stress is mounting, take 10 minutes and brew a mug of oolong tea to help you relax.

WHITE TEA:

Tea has been used as medicine for centuries. Now modern science is discovering what people in China and throughout the world have long known: tea is good for you. While green and black tea are very healthy, white tea is the least processed tea and has the highest antioxidant levels. It may be the supreme Drink of Health.

White Tea Antioxidants

Antioxidants are nutrients that protect the body from damage by free radicals. Free radicals are nasty things that go around wreaking havoc on your body, damaging DNA and accelerating aging. Antioxidants scoop them up and neutralize them. White tea is loaded with these protective nutrients.

Cancer Prevention

White tea may have profound power against cancer-causing cells and against many different types of cancer, such as colon, prostate, and stomach cancers. Flavonoids, a class of antioxidants, inhibit the growth of cancer cells and prevent the development of new ones. In some cases, white tea has been found to work as well as prescription drugs, but without the side effects.

Lower Blood Pressure

Studies show that white tea can thin the blood and improve artery function. It helps lower high blood pressure and maintain a healthy one. By promoting strong and healthy blood vessels, white tea guards against the ravages of stroke.

Lower Cholesterol

Catechins, another group of antioxidants, have been found to reduce cholesterol, and white tea is teeming with them. Cholesterol is a special type of fat and is necessary for health. There is good cholesterol and bad cholesterol, and white tea increases the good while decreasing the bad. This helps prevent hardening of the arteries and blockage of blood flow.

Heart Protection

By thinning the blood, lowering blood pressure, and reducing cholesterol, white tea protects the heart and the entire circulatory system. Researchers have also discovered that people who drink 2 or more cups of tea a day are almost 50% less likely to die after suffering a heart attack. White tea is truly a remarkable heart tonic.

Stronger Bones

Studies have found that people who drank tea regularly had greater bone density and strength than non-drinkers. White tea may also have beneficial effects for sufferers of arthritis and osteoporosis.

Antibacterial & Antiviral

White tea is a natural killer of bacteria and viruses. The antioxidants so abundant in white tea tone the entire immune system, providing protection against a variety of invaders and a wide range of diseases. Its helps guard against the common cold and flu, and can ease the symptoms of HIV.

Healthy Teeth and Gums

White tea contains small amounts of fluoride and other nutrients which keeps the teeth strong and healthy. It also kills the bacteria which causes plaque, tooth decay, and bad breath.

Healthy Skin

Free radicals from staying out in the sun too long, stress, and a poor diet can damage the skin and cause it to prematurely age. By scavenging these free radicals, white tea protects the skin and helps to reverse some of the damage. Drinking white tea promotes healthy and radiant skin.

Other Health Benefits

White tea has many other benefits to offer. It may reduce blood sugar and help prevent and alleviate the symptoms of diabetes. It reduces stress and increases energy.

White tea may or may not aid in weight-loss. Studies suggest tea may increase metabolism and encourage the body to burn more fat, but a balanced diet and regular exercise are more likely to produce results. Still, adding white tea to your weight-loss plan can't hurt.

GREEN TEAS:

Green tea is made solely from the leaves of Camellia sinensis that have undergone minimal oxidation during processing. Green tea originates in China and has become associated with many cultures throughout Asia. It has recently become more widespread in the West, where black tea is traditionally consumed. Many varieties of green tea have been created in countries where they are grown. These varieties can differ substantially due to variable growing conditions, horticulture, production processing, and harvesting time.

Over the last few decades green tea has been subjected to many scientific and medical studies to determine the extent of its long-purported health benefits, with some evidence suggesting that regular green tea drinkers may have a lower risk of developing heart disease and certain types of cancer. Although green tea does not raise the metabolic rate enough to produce immediate weight loss, a green tea extract containing polyphenols and caffeine has been shown to induce thermogenesis and stimulate fat oxidation, boosting the metabolic rate 4% without increasing the heart rate.

According to a survey released by the United States Department of Agriculture in 2007, the mean content of flavonoids in a cup of green tea is higher than that in the same volume of other food and drink items that are traditionally considered of health contributing nature, including fresh fruits, vegetable juices or wine. Flavonoids are a group of phytochemicals in most plant products that are responsible for such health effects as anti-oxidative and anticarcinogenic functions. However, based on the same USDA survey, the content of flavonoids may vary dramatically amongst different tea products.

HEALTH BENEFITS OF GREEN TEA:

• Green tea is a natural remedy and it is beneficial for pain and other medical problems. The history of green tea can be traced down since ages. People used to have green tea during the ancient times; it is still as valuable and good as in ancient times. Numerous wonders are hidden in this herbal drink.  Primeval Chinese people have used it for medical purposes as they knew green tea was favorable for health. Green tea is useful for headaches and depressions. Chinese history holds great importance for green tea. Leaves of Camellia Sinuses are used for producing green tea by some special processes. Green tea has a little amount of caffeine which causes insomnia, nausea and frequent urination.
• Green tea can benefit in several ways.
• -Treatment of multiple sclerosis.
• -Treatment and prevention of cancer.
• -Helps in stopping Alzheimer's and Parkinson's diseases.
• -It is used in raising metabolism and increasing fat oxidation.
• -Reduces heart diseases and attacks.
• -Reduces the level of cholesterol in blood, improves the ratio of good cholesterol to bad cholesterol.
• -Used in treatment of rheumatoid arthritis and cardiovascular diseases.
• -It is used to treat impaired immune function.
• -Keep your teeth healthy and kills bacteria which causes the dental plaque.
• -Treatment and prevention of skin cancer.
• -Regular consumption of green tea can effectively delay symptoms of ageing.-The people who take green tea regularly do not fall prey to common viral & bacterial infections easily.
• -Green tea increases stamina and boost endurance.
• -Aiding in proper digestion
• -Green tea increases hydration through the consumption of more water.
• -Effective in the treatment of multiple sclerosis.
• -Reduces and prevents acne. Drink a cup of green tea regularly and you will not have acne problems.
• -Green tea reduces risk of thrombosis, arterial sclerosis, cerebral strokes etc.
• -It reduces the risk of esophageal cancer.
• -Green tea has certain vitamins that prevent abnormal formation of blood clotting in the wounds.