Tea Acidity
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Tea Botanical name: Common name: Parts used: System effected: Properties:
Camellia sinensis Green tea Young leaves and leaf buds Liver, heart Stimulant, diuretic. Astringent
Tea is made from young leaves and buds of tea plant. Tea leaves are rich in caffiene (an alkaloid). Besides caffiene, tea leaves contain tannic acid and coloring matter, such as polyphenolic compounds. The relative amounts of these substances are different in different varieties of tea leaves, i.e. why, their taste and flavour are different. The brownish colour of tea is due to the peresence of polyphenolic compoundes and some inorganic ions like Mn2+, Fe3+ etc. Some simple experimemts can be carried out to study the compomnrntds that are resoponsibe for the variation in tea flavour in various brands of tea
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The History of Tea Drinking tea plays such a central part in our lives, it is such a universal phenomenon with millions of people the world over enjoying their tea on a daily basis, that it’s hard to imagine a world without tea and yet while the Eastern world has been using tea for more than 4500 years, for most of this time tea was unknown in the Western world. Tea was only introduced into the West a relatively recent 400 years ago. Discovered in China, tea has exerted a profound influence on societies and cultures throughout the world so that there are unique ceremonies in various cultures and most parts of the world have social etiquettes concerning the preparation and drinking of tea as well as social customs regarding how, when and where to drink it
The Origin of the Word "Tea" The Chinese originally called it “Kia”. As far as is know it was during the course of the 6th century AD that the name evolved into "Cha". On its arrival in the West it became Té which is still the name for tea in many countries.
The Discovery of Tea Legend has it that tea was discovered by the Chinese Emperor, Shen Nong, in 2737 B.C. The Emperor had a habit of boiling his drinking water. One day while he was in his garden a few tea leaves fell by chance into his boiling water which then gave off a rich, alluring aroma. The Emperor, upon drinking this brew, discovered it to be refreshing and energizing. He immediately gave the command that tea bushes to be planted in the gardens of his palace and declared it gave one “vigor of body, contentment of mind and determination of purpose”.
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A History of Tea Timeline 2737 B.C.
The second emperor of China, Shen Nung, discovers tea when tea leaves blow into his cup of hot water or so the story goes.
350 A.D.
A Chinese dictionary cites tea for the first time as Erh Ya
618907A.D.
(T’ang Dynasty) Tea becomes a popular drink in China for both its flavor and medicinal qualities.
725
The Chinese give tea give its own character ch’a.
960-1280
Sung Dynasty Chinese tea drinking is on the rise, as are elegant teahouses and teacups carefully crafted from porcelain and pottery.
1191
Japanese Buddhist Abbot Eisai, who introduced Zen Buddhism to Japan, brings tea seeds from China and plants them around his Kyoto temple.
1211
Japanese Buddhist Abbot Eisai writes the first Japanese tea book Kitcha-Yojoki (Book of Tea Sanitation).
1484
Japan's shogun Yoshimasa encourages tea ceremonies, painting, and drama.
End of 1500s
Japanese tea master Sen-no Rikyu opens the first independent teahouse and evolves the tea ceremony into its current simple and aesthetic ritual. During this ceremony, one takes a garden path into a portico, enters upon hearing the host’s gong, washes in a special room, and then enters a small tearoom that holds a painting or flower arrangement to gaze upon. The tea master uses special utensils to whisk the intense powdered tea. Tea drinkers enjoy the art or flowers and then smell and slurp from a shared tea bowl.
1664
English East India Company brings the gift of tea to the British king and queen. The British take over New Amsterdam, name it New York, and a British tea tradition ensues.
1706
Thomas Twining serves up tea at Tom’s Coffee House in London.
1835
The East India Company starts the first tea plantations in Assam, India.
1904
Englishman Richard Blechynden creates iced tea during a heat wave at the St Louis World Fair.
1904
Green tea and Formosan (Taiwanese) tea outsells black tea by five times in the U.S.
1908
New York tea importer Thomas Sullivan inadvertently invents tea bags when he sends tea to clients in small silk bags, and they mistakenly steep the bags whole.
1909
Thomas Lipton begins blending and packaging his tea in New York.
1910
Sumatra, Indonesia becomes a cultivator and exporter of tea followed by Kenya and parts of Downloaded from www.icbse.com
Africa.
Types of Tea Anti Acidity Tea Anti Acidity Tea is brewed from the leaf of Aspalathus linearis, a unique herb with great healing powers. It is less astringent, completely caffeine-free, no oxalic acid and doesn't contain tannins that may interfere with iron absorption. However, it has a higher content of fluoride which might help to protect against tooth decay. Besides, it is rich in a variety of minerals, including potassium, copper, magnesium, calcium, iron, zinc and manganese. This tea is generally beneficial to the digestive system & relaxes spasms. It has been used in the treatment of vomiting, diarrhea & other mild gastric symptoms. It has also been shown to be of benefit in the treatment of a wide range of allergies especially milk allergy, eczema, hay fever & asthma in infants. Anti-acidity tea helps to excrete uric acid which causes gout & lower body acidity.
Anti Aging Herbal Tea Anti-aging herbal tea is made of an herb which is indigenous to the Cedarburg area of South Africa. Due to its widely publicized health benefits, anti aging herbal tea has grown into a billion dollar export industry since the mid twentieth century. The tea has no caffeine and only half the tannin of ordinary tea. Apart from being refreshing to drink, in place of ordinary tea and coffee, it has the advantage of containing minerals and powerful antioxidants. Having no oxalic acid it also does not irritate the kidneys. This herbal tea controls aging, hypertension /stress & blood pressure & cardiac problems. It also fights with fatigue, joint pains, gastric & cough problems, chronic & acute diseases of males and females and gives over all fitness, strength & potential to the body and mind. It stimulates the release of growth hormones (as it decreases with age) in pituitary gland which is responsible for all body functions and maintains youth by keeping physical and mental health. It is useful in keeping normal sexual drive and good relaxing sleep.
Anti Cough Tea This tea is made of an unique mixture of herbs having very good cough formula and analgesic. It is known to exhibit health properties like: • Good as immunomodulator for skin health • Protects from asthma, cough, leucorrhoea, chronic rheumatism and cancer, etc. • Anti-bacterial • Anti-fungal • Anti-viral • Tonic • Diuretic • Blood purifier • Anti-inflammatory Downloaded from www.icbse.com
Herbs which are useful and used as ingredient in anti cough tea are amla, elaichi, tulsi, vasaka, garlic and ginger.
Green Tea Green tea is a "true" tea, meaning it is made solely with the green tea leaves (Camellia sinesis), that have undergone minimal oxidation during processing. Green tea originates from China and has become associated with many cultures in Asia from Japan to the Middle East. Drinking green tea and herbal green tea is reputed to be helpful in treating cancer, high cholesterol levels, rheumatoid arthritis, cariovascular disease, impaired immune function and infection . Other traditional uses of herbal green tea include treating flatulence (gas), regulating body temperature and blood sugar, promoting digestion, and improving mental processes. It has been extensively studied in people, animals, and laboratory experiments. Green tea is produced by steaming the leaves to destroy the enzymes that might otherwise ferment the leaves. The leaves are then rolled either by hand or by mechanical rollers, to bring out the juices in the leaves that are responsible for its flavor. The rolled leaves are then fired to dry them. The entire process of rolling and firing is repeated several times until the leaves are completely dry. The process of producing green tea is very exacting because variation in the drying time can result in fermentation of the leaves which spoils its flavor.
Herbal Tea Herbal tea has been in use since a long period of time. It is also known as a herbal infusion or tisane. Herbal tea is basically the mixing of dried fruit, flower or herb in boiling water. It is natural, free of caffeine free. There is no artificial coloring or flavors. A mixture of aromatic, carminative, sedative, expectorant herbs, which have their own importance, it has lot of beneficial effect on health, body and mind. It is gaining popularity due to its multi effects. Herbs are used in their natural forms and these herbs are without any chemical treatment. There is nothing like a cup of delicious herbal tea to nourish and soothe the body and mind.
Lemongrass Tea Lemon grass is also known as Cymbopogon citratus, and has certain therapeutic properties and the reported benefits of using it internally, in the form of a herbal tea (infusion) are reducing fevers, stomach cramps, flatulence and colic, easing arthritic pain, general digestive aid . It is especially suited for digestive problems in children. Lemon grass is commonly used in teas, soups, and curries. It is also suitable for poultry, fish, and seafood. It is widely used as a herb in Asian (particularly Vietnamese, Hmong, Khmer, Thai, Lao, Malaysian, Indonesian, Philippine, Sri Lankan) and Caribbean cooking. It has a citrus flavor and can be dried and powdered, or used fresh. Dried lemon grass leaves to make a zesty, refreshing drink that is highly satisfying both hot and cold.
Moringa Green Tea There is an old saying: "Moringa leaves prevent 300 diseases." Moringa green tea set the free radicals, purifies blood, reduces stress of smokers and alcohol drinkers. Indeed, induces No-Smoke temptation. Dead cells of the skin are removed and improves glows and shine. It is highly beneficial for pregnant women, lactating mothers and working women for its soothing powers. Downloaded from www.icbse.com
Regular consumption of Moringa Green Tea keeps people consuming it in refreshing mood and keeps their body fit with improved performance and memory. This is due to cleaning effect of Moringa Green tea. This is an organic product and cultivated in a natural environment, under the vigilance of horticultural experts.
Organic Tea Dr. John Weisburger, Director Emeritus, American Health Foundation tells about organic tea that “Current research shows tea contains specific antioxidants & health promoting ingredients. Lowering the risk of heart disease, stroke & certain types of cancer link, pancreatic and prostrate." The greatest organic tea benefit is the presence of polyphenol oxidase - an abundant supply of antioxidants. They can be termed as the “true elixir” of life. The activity of antioxidants in tea is more than that in over 21 fruits and vegetables. Tea qualifies as organic only when environment-friendly techniques are used in its production. Demand for organic tea, like other organic foods, has also been growing rapidly.
Orthodox Tea The top two leafs of each tea plant is the orthodox tea. It is said that these leaves produce the best quality tea leaf and since even today, leaves are plucked by hands, we ensure that we collect only these leaves to make our orthodox tree. The demand for orthodox tea is rising worldwide even as India produces a meagre 80 mkg of this tea annually out the total production of more than 900 mkg. Although Orthodox Tea is somewhat similar to Green Tea, it requires even finer tea leaves than the latter. It is sold domestically through auction centers and is exported in small quantities overseas.
Slimming Tea Slimming tea is known to help digest fatty foods. Made of natural herbs, such tea increases metabolism and help to reduce your cholesterol levels. It suppresses the appetite, detoxify, cleanse and rid the body of excess fat. Such tea does not cause you diarhea, instead they treat obesity from the root. Such tea can also be used for coronary heart diseases. It also reduces blood sugar levels. Consuming this tea also reduces stretch marks and melts cellulite naturally. Overweight patients suffering from a feeling of heaviness, fatigue, and body pain have also experienced relief on consumption of this tea. Slim tea also helps clear up body channels.
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The Health Benefits of Tea The main advantage of tea lies in the fact that it is a completely natural product, without any added flavorings, colors or preservatives. Likewise, when drunk without adding any sugar, honey or milk, tea has no calories and simultaneously serves as a crucial component for maintaining the balance of body liquids.
Research into the Health Benefits of Tea •
•
•
• • • • •
Tea leaves contain a high amount of polyphenols, which are a type of antioxidant, and that regular consumption of about five cups of tea per day contributes to keeping a high level of them in the bloodstream. The antioxidants work to neutralize free radicals. The free radicals are oxidizing molecules which naturally and harmlessly exist within the human body. However, they accumulate as a result of physiological processes such as metabolism, and are furthermore found in environmental factors such as polluted air, poisonous waste and cigarette smoke. Tea prevents the rise of homocysteine which is known to be an important and significant risk factor for cardiovascular diseases, due to the content of vitamin M in tea. The vitamin M, which is a B complex vitamin, assists in preventing cancer and it also plays an important part in the health of the nervous system, the eyes and other systems. Tea leaves contain fluoride which helps strengthen bones and teeth and fights cavities. Tea believed to boost the body’s defenses A green tea component helps kill leukemia cells Drinking tea might delay Alzheimer's Disease Tea may play a role as an AIDS fighter
Tea and Caffeine Caffeine is a natural substance found in numerous plants. Its consumption helps with metabolism, weight loss and vitality. The average amount of caffeine from brewed tea leaves depends on the type of tea (black tea contains more caffeine than green tea), the brewing duration, and the water temperature (the higher the temperature- the greater the amount of caffeine drained from the leaves). A healthy individual can consume up to about 350 mg of caffeine per day without any concern. Caffeine content per serving (milligrams) Brewed Tea
8 oz. Serving
Black tea
40
Green tea
40
Iced tea, ready to drink
30
Iced tea mix, unsweetened
13
Bottled Tea
8 oz. Serving Downloaded from www.icbse.com
Nestea Lemon Sweet
11
Lipton Brisk, All Varieties
6
Harmful Effects of Tea Harmful effects of Caffeine When taken before bedtime, caffeine can interfere with getting to sleep or staying asleep. Exactly how caffeine will affect an individual? And for how long, depends on many factors, • The amount of caffeine ingested • Whether one is male or female • One's height and weight • One's age • Whether one is pregnant • Whether one smokes Caffeine is converted by the liver into substances that are excreted in the urine. Some people are more sensitive to the effects of caffeine than others. With frequent use, tolerance towards many of the effects of caffeine will develop. At doses of 600 milligrams (about six cups of coffee) or more daily, caffeine can cause nervousness, sweating, tenseness, upset stomach, anxiety , and insomnia. It can also prevent clear thinking and increase the side effects of certain medications. This level of caffeine intake represents a significant health risk. Caffeine can be mildly addictive. Even when moderate amounts of caffeine are withdrawn for 18 to 24 hours, one may feel symptoms such as headache, fatigue, irritability, depression, and poor concentration. The symptoms peak within 24 to 48 hours and progressively decrease over the course of a week. To minimize withdrawal symptoms, experts recommend reducing caffeine intake gradually.
Harmful Effects of Drinking Excessive Tea People drink tea to relax. A sizzling cup is refreshing. Yet, excessive tea is not advisable. It is harmful to health. It slowly affects the body systems. The habit of drinking too much tea should be avoided. Tea is prepared from leaves of shrub belonging to camellia family. The plant is a native of south East Asia. The earliest record of its cultivation comes from China in 4th century AD. The chemical composition of tea leaves are as follows: Moisture: 5 – 8% Aromatic oils: 0.5% Downloaded from www.icbse.com
Caffeine: 2.5 – 5% Nitrogen: 4.75 – 5.5% Soluble substances: 38 – 45% Tannin: 7 – 14% Minerals: 5 – 5.75% The primary effects of tea are due to alkaloids, caffeine, tannin and aromatic oils. It is not only composition of tea leaves that is harmful but also the composition of infusion which is prepared by boiling tea with water. The harmful effects of drinking excessive tea in case of specific diseases are as summed below: Indigestion: Tea is said to slow down digestion. It impedes the action of ptyalin, a digestive ferment of saliva which acts as cooked starch. Tannin is responsible for inhibition of this condition. This effect could however disappear once milk is added as milk precipitates tannin. Tea also delays stomach digestion and could lead to gas formation diarrhoea and constipation. Kidney disorders: Experiments show that 5 cups of tea increases the urine by 400 – 500% in people vulnerable to kidney related ailments. This continued stimulation of kidneys by caffeine might damage them. Tea could also promote kidney stone because of its high concentration of oxalate. Premenstrual syndrome: Drinking tea could aggravate symptoms of premenstrual syndrome. According to a research conducted under Dr Annette Rossignol, an associate professor of public health at Oregon University, women in China who drank between 1 – 4 cups of tea a day were twice as likely to have PMS then non tea drinkers. Drinking 8 cups of tea increased the PMS occurrence 10 times. Incontinence: Drinking too much tea could lead to incontinence or frequent/urgent impulse to urinate. According to a recent study conducted at St. George’s Hospital London, caffeine could exert pressure on bladder by causing muscle surrounding it to contract increasing the need to urinate. The respiratory and cardiac muscles are also stimulated by caffeine as coronary arteries get dilated resulting in the increase in the rate of blood flow. The quickening of respiration lowers the level of carbon dioxide and increases the heat production of body by 10 – 20%.
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Ceremonies and Cultures China - The Original Tea Ceremony The Chinese tea ceremony is the most ancient ceremony and plays a central role in Chinese culture. The tea is the heart of the ceremony: the host and ceremony participants smell the tea, taste it and enjoy the many layers of taste discovered with every mouthful. The tea ceremony reflects the search for beauty in every object of the world, in accordance with the Chinese Tao philosophy. The ceremony must be conducted in a peaceful atmosphere and induce a sense of tranquility and harmony among the participants. The tea ceremony is conducted for various purposes: anything from expressing appreciation or asking forgiveness, to creating goodwill among the guests of family reunions or wedding celebrations.
Japan - Motifs of Harmony and Aesthetics The tea ceremony is conducted in the "tearoom", which every traditional Japanese house has. The tearoom is considered to be an island of tranquility and purity, allowing the guests to leave the outside world behind and relax. Artistic motifs influenced by Japanese architecture, drawing and sculpture, are interwoven into the tea ceremony and influence the design of the tearoom and the ceremonial tea dishes. The modern Japanese culture considers tea to be a social drink and gives it a central role in their lifestyle, but the traditional tea ceremony is almost never conducted any longer in daily life. The tea ceremony holds a place of honor in Japanese culture as a magnificent trace of the past. There are currently three tea schools in Japan, established 300 years ago, which continue to bequeath the art of tea and Japanese hosting.
Russia - Samovar And Strong Tea
At the beginning of the 17th century, the Chinese Emperor presented the Russian Czar with a gift of tea. Tea culture is an integral part of Russian Downloaded from www.icbse.com
culture and is referred to in works of art and literature. The samovar, a metal container for heating water, can be found in almost every home and is part of the Russian cultural icons. The Russians tend to prepare a strong, bitter concentrate of black tea which is kept in a small teapot next to the samovar. The concentrate is diluted with boiling water to prepare tea according to the drinker's preferred strength.
Great Britain - Tea With Milk
The British are among the world's most massive tea consumers. Perhaps it is possible to understand the importance of tea in British culture if we recall Sir Winston Churchill's declaration during the Second World War that: "Tea is more important to the soldiers than munitions". Black tea was very common in Britain during the 18th century and the British founded the tradition of adding milk to black tea.
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Contents of Tea 1. Tannic Acid 2. Polyphenol 3. Caffiene
1.
Tannic acid
Synonyms: Gallotannic acid, Gallotannin, Galloylglucose, Glycerite, Quebracho, Tannins Molecular formula Molecular Weight Melting Point Flash point Water Solubility
: : : : :
C76H52O46 1701.22 218 °C 198 °C 250 g/L (20 °C)
Properties:
Tannic acid has anti-bacterial, bacterial, anti anti-enzymatic and astringent properties. Tannic acid has constringing action upon mucous tissues such as tongue and inside of mouth. The ingestion of tannic acid caused constipation and can be used to treat diarrhoea (in thee absence of fever or inflammation). The anti antioxidant and anti-mutagenic mutagenic properties of tannic acid are beneficial. Externally, tannic acid is used to treat ulcers, toothache and wounds. Facts about Tannic Acid:
Tannic acid is also used in many industrial applications. The best known is the tanning of leather. Tannic is acid is sometimes used to clear wines. Tannic acids reacts with proteins in wine to form insoluble complexes which sediment or can be filtered. Description:
Tannic acid is a polymer of Gallic acid molecules and glucose. It the example there are 3 Gallic acid molecules, but normally there are about 8. Because there are different molecular structures for tannic acid it would have been better to speak about tanni tannicc acids (in plural). Tannic acid will hydrolyze into glucose and Gallic or ellagic acid units. Tannic acid is odorless but has a very astringent taste. Pure tannic acid is a light yellowish and amorphous powder powder.
2.
Caffiene
Synonyms: 1, 3, 7-Trimethylxanthi nthin Molecular formula Molecular Weight Water Solubility
: C8H10N4O2 : 194.19 94.19 gm/mol : 2.17 g/100 ml (25 °C) 18.0 g/100 ml (80 °C) 67.0 g/100 ml (100 °C) Downloaded from www.icbse.com
Properties:
Caffeine acts on the nervous system by blocking adenosine receptor thereby slowing down nerve cell activity. Caffeine stimulates the central nervous system, respiration and blood circulation. Caffeine also acts as a diuretic. Caffeine increases the circulation and oxidation of fatty acids. This is why caffeine is used by sportsmen to increase fatty acid metabolism. Caffeine is often used in combination with aspirin to treat headaches. Facts about Caffeine:
from caffeine containing plants was used to treat headaches, coughs and even plague. Only recently caffeine is used to stay awake and relieve fatigue. Caffeine is now one of the most widely used phytochemical. Description:
Caffeine is a water-soluble alkaloid. Pure caffeine is a white odorless crystalline powder with a very bitter taste. Caffeine is closely related to other alkaloids such as theophylline (mainly found in tea) and theobromine (mainly found in cacao beans). Distribution:
Caffeine is found in many everyday products, including tea, cola nuts, coffee, chocolate, mate and guarana. It is also found in some soft drinks (mainly colas and energy drinks) where it is artificially added.
3.
Polyphenol
Tea polyphenol is one of the main ingredients in tea and takes up 12-24% of the tea. Drinking a cup of polyphenol-enriched oolong tea with a high fat meal may increase the amount of cholesterol excreted by the body by half, says a small study from Japan and Taiwan. The health benefits, which have mainly focused on green tea, have been linked to the polyphenol content of the tea. Green tea contains between 30 and 40 per cent of water-extractable polyphenols, while black tea (green tea that has been oxidized by fermentation) contains between 3 and 10 per cent. Oolong tea is semifermented tea and is somewhere between green and black tea. Polyphenols are most definitely antioxidants, which means that they can reduce the risk of developing coronary artery disease and a number of other health problems. Thepolyphenols found in tea have also been linked with cancer reduction, as they appear to block the action of some enzymes linked with cancer. The polyphenols found in tea also appear to suppress the growth of harmful bacteria, while promoting beneficial bacteria in the gut.
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Experiment 1 Compare the water soluble polyphenol (catechin) content in the various samples of tea leaves. Bunsen burner, tripod stand, wire gauge, beaker, funnel, filter paper, chemical balance Tea contains upto 30% of the water soluble polyphenols (catechin). These are largely responsible for the flavour if the tea. To estimate the extent of these compounds in a given sample, the tea leaves are immersed in hot water for equal time and the loss in the weight of tea leaves is determined. 5gm of 3 different tea leaves. Distilled water.
Aim: Materials Required Theory:
Things Required: Chemicals Used: Procedure:
1. Weigh exactly 5gm of 1st sample of tea leaves. 2. Take 100ml of distilled water in a beaker. 3. Put tea leaves in above beaker and boil it for 10 minutes. 4. Filter above boiled solution using funnel and filter paper in another beaker. Store the residue aside and them dry. 5. Weigh the dried residue. 6. Repeat the above 1-5 steps for the other two samples. Observations: S.No. Brand Name of Tea
Initial Weight (x gms)
Final Weight (y gms)
Loss of Weight
% of water soluble component = (y/x)*100
1. Red Label 2. Honey Gold Tea 3. Taza Tea Result: The tea having better flavour has more polyphenol content.
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Experiment 2 Compare the tannic acid content in the various samples of tea leaves. Bunsen burner, tripod stand, wire gauge, beaker, funnel, filter paper, chemical balance The tannic acid present on the tea leaves is precipitated as calcium tannate by treatment of aqueous solution of tea with Calcium Carbonate. Calcium tannate is the hydrolysed with conc. H2SO4 and recrystallized from water. 5gm of 3 different tea leaves. Calcium Carbonate (CaSO4).
Aim: Materials Required Theory:
Things Required: Chemicals Used: Procedure:
1. Weigh exactly 5gm of 1st sample of tea leaves. 2. Take 100ml of distilled water in a beaker. 3. Put tea leaves in above beaker and boil it for 10 minutes. 4. Filter above boiled solution using funnel and filter paper in another beaker. 5. In filtrate add 2gms of CaCO3 and boil it. 6. Filter above boiled solution using funnel and filter paper in another beaker. There will be a ppt. of Calcium tannate on the filter paper. 7. Keep filter paper aside and let it dry. 8. Weigh the ppt. of tannic acid. 9. Repeat the above 1-8 steps for the other two samples. Observations: S.No. Brand Name of Tea 1. Red Label 2. Honey Gold Tea 3. Taza Tea
Weight of tea leaves taken(x gms)
Weight of tannic acid obtained (y gms)
% of tannic acid= (y/x)*100
Result: The tea sample containing higher percentage of tannic acid gives better flavour.
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Experiment 3 Compare the caffiene content in the various samples of tea leaves. Bunsen burner, tripod stand, wire gauge, beaker, funnel, filter paper, chemical balance, conical flask, cork Tea containd caffiene upto 4%. It is more soluble in chloroformthan in water. 5gm of 3 different tea leaves. dilute H2SO4, Cloroform.
Aim: Materials Required Theory: Things Required: Chemicals Used: Procedure:
1. Weigh exactly 5gm of 1st sample of tea leaves. 2. Take 100ml of distilled water in a beaker. 3. Put tea leaves in above beaker and boil it for 10 minutes. 4. Filter above boiled solution using funnel and filter paper in another beaker. 5. In filtrate add 2gms of CaCO3 and boil it. 6. Filter above boiled solution using funnel and filter paper in another beaker. There will be a ppt. of Calcium tannate on the filter paper. 7. Add 10ml of H2SO4 to the filtrate and boil it. 8. Filter above boiled solution using funnel and filter paper in conical flask. There will be a ppt. of PbSO4 on the filter paper. Discard the filter paper. 9. Add 5ml of Chloroform to it. Cork the flask and shake it well. 10. Filter above solution using funnel and filter paper in another conical flask. There will be a ppt. of Caffeine. Add 5ml of Chloroform to the filtrate. Cork the flask and shake it well. Filter the solution in same funnel. Repeat this step 4 times to extract all the Caffeine present in the solution. 11. Weigh the filter paper. 12. Repeat the above 1-11 steps for the other two samples Observations: S.No.
Brand Name of Tea
Weight of tea leaves taken(x gms)
Weight of caffiene obtained (y gms)
% of caffiene= (y/x)*100
1. Red Label 2. Honey Gold Tea 3. Taza Tea Result: The tea sample containing higher percentage of caffiene gives better flavour.
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Bibliography 1. http://www.inpursuitoftea.com/ 2. http://www.icbse.com
Some good books on tea: Tea: bioactivity and therapeutic potential
By Yong-su Zhen
Healing teas: how to prepare and use teas to maximize your health The book of tea
By Marie Nadine Antol
By Kakuzō Okakura
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Camellia sinensis Green tea Young leaves and leaf buds Liver, heart Stimulant, diuretic. Astringent
Tea is made from young leaves and buds of tea plant. Tea leaves are rich in caffiene (an alkaloid). Besides caffiene, tea leaves contain tannic acid and coloring matter, such as polyphenolic compounds. The relative amounts of these substances are different in different varieties of tea leaves, i.e. why, their taste and flavour are different. The brownish colour of tea is due to the peresence of polyphenolic compoundes and some inorganic ions like Mn2+, Fe3+ etc. Some simple experimemts can be carried out to study the compomnrntds that are resoponsibe for the variation in tea flavour in various brands of tea
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The History of Tea Drinking tea plays such a central part in our lives, it is such a universal phenomenon with millions of people the world over enjoying their tea on a daily basis, that it’s hard to imagine a world without tea and yet while the Eastern world has been using tea for more than 4500 years, for most of this time tea was unknown in the Western world. Tea was only introduced into the West a relatively recent 400 years ago. Discovered in China, tea has exerted a profound influence on societies and cultures throughout the world so that there are unique ceremonies in various cultures and most parts of the world have social etiquettes concerning the preparation and drinking of tea as well as social customs regarding how, when and where to drink it
The Origin of the Word "Tea" The Chinese originally called it “Kia”. As far as is know it was during the course of the 6th century AD that the name evolved into "Cha". On its arrival in the West it became Té which is still the name for tea in many countries.
The Discovery of Tea Legend has it that tea was discovered by the Chinese Emperor, Shen Nong, in 2737 B.C. The Emperor had a habit of boiling his drinking water. One day while he was in his garden a few tea leaves fell by chance into his boiling water which then gave off a rich, alluring aroma. The Emperor, upon drinking this brew, discovered it to be refreshing and energizing. He immediately gave the command that tea bushes to be planted in the gardens of his palace and declared it gave one “vigor of body, contentment of mind and determination of purpose”.
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A History of Tea Timeline 2737 B.C.
The second emperor of China, Shen Nung, discovers tea when tea leaves blow into his cup of hot water or so the story goes.
350 A.D.
A Chinese dictionary cites tea for the first time as Erh Ya
618907A.D.
(T’ang Dynasty) Tea becomes a popular drink in China for both its flavor and medicinal qualities.
725
The Chinese give tea give its own character ch’a.
960-1280
Sung Dynasty Chinese tea drinking is on the rise, as are elegant teahouses and teacups carefully crafted from porcelain and pottery.
1191
Japanese Buddhist Abbot Eisai, who introduced Zen Buddhism to Japan, brings tea seeds from China and plants them around his Kyoto temple.
1211
Japanese Buddhist Abbot Eisai writes the first Japanese tea book Kitcha-Yojoki (Book of Tea Sanitation).
1484
Japan's shogun Yoshimasa encourages tea ceremonies, painting, and drama.
End of 1500s
Japanese tea master Sen-no Rikyu opens the first independent teahouse and evolves the tea ceremony into its current simple and aesthetic ritual. During this ceremony, one takes a garden path into a portico, enters upon hearing the host’s gong, washes in a special room, and then enters a small tearoom that holds a painting or flower arrangement to gaze upon. The tea master uses special utensils to whisk the intense powdered tea. Tea drinkers enjoy the art or flowers and then smell and slurp from a shared tea bowl.
1664
English East India Company brings the gift of tea to the British king and queen. The British take over New Amsterdam, name it New York, and a British tea tradition ensues.
1706
Thomas Twining serves up tea at Tom’s Coffee House in London.
1835
The East India Company starts the first tea plantations in Assam, India.
1904
Englishman Richard Blechynden creates iced tea during a heat wave at the St Louis World Fair.
1904
Green tea and Formosan (Taiwanese) tea outsells black tea by five times in the U.S.
1908
New York tea importer Thomas Sullivan inadvertently invents tea bags when he sends tea to clients in small silk bags, and they mistakenly steep the bags whole.
1909
Thomas Lipton begins blending and packaging his tea in New York.
1910
Sumatra, Indonesia becomes a cultivator and exporter of tea followed by Kenya and parts of Downloaded from www.icbse.com
Africa.
Types of Tea Anti Acidity Tea Anti Acidity Tea is brewed from the leaf of Aspalathus linearis, a unique herb with great healing powers. It is less astringent, completely caffeine-free, no oxalic acid and doesn't contain tannins that may interfere with iron absorption. However, it has a higher content of fluoride which might help to protect against tooth decay. Besides, it is rich in a variety of minerals, including potassium, copper, magnesium, calcium, iron, zinc and manganese. This tea is generally beneficial to the digestive system & relaxes spasms. It has been used in the treatment of vomiting, diarrhea & other mild gastric symptoms. It has also been shown to be of benefit in the treatment of a wide range of allergies especially milk allergy, eczema, hay fever & asthma in infants. Anti-acidity tea helps to excrete uric acid which causes gout & lower body acidity.
Anti Aging Herbal Tea Anti-aging herbal tea is made of an herb which is indigenous to the Cedarburg area of South Africa. Due to its widely publicized health benefits, anti aging herbal tea has grown into a billion dollar export industry since the mid twentieth century. The tea has no caffeine and only half the tannin of ordinary tea. Apart from being refreshing to drink, in place of ordinary tea and coffee, it has the advantage of containing minerals and powerful antioxidants. Having no oxalic acid it also does not irritate the kidneys. This herbal tea controls aging, hypertension /stress & blood pressure & cardiac problems. It also fights with fatigue, joint pains, gastric & cough problems, chronic & acute diseases of males and females and gives over all fitness, strength & potential to the body and mind. It stimulates the release of growth hormones (as it decreases with age) in pituitary gland which is responsible for all body functions and maintains youth by keeping physical and mental health. It is useful in keeping normal sexual drive and good relaxing sleep.
Anti Cough Tea This tea is made of an unique mixture of herbs having very good cough formula and analgesic. It is known to exhibit health properties like: • Good as immunomodulator for skin health • Protects from asthma, cough, leucorrhoea, chronic rheumatism and cancer, etc. • Anti-bacterial • Anti-fungal • Anti-viral • Tonic • Diuretic • Blood purifier • Anti-inflammatory Downloaded from www.icbse.com
Herbs which are useful and used as ingredient in anti cough tea are amla, elaichi, tulsi, vasaka, garlic and ginger.
Green Tea Green tea is a "true" tea, meaning it is made solely with the green tea leaves (Camellia sinesis), that have undergone minimal oxidation during processing. Green tea originates from China and has become associated with many cultures in Asia from Japan to the Middle East. Drinking green tea and herbal green tea is reputed to be helpful in treating cancer, high cholesterol levels, rheumatoid arthritis, cariovascular disease, impaired immune function and infection . Other traditional uses of herbal green tea include treating flatulence (gas), regulating body temperature and blood sugar, promoting digestion, and improving mental processes. It has been extensively studied in people, animals, and laboratory experiments. Green tea is produced by steaming the leaves to destroy the enzymes that might otherwise ferment the leaves. The leaves are then rolled either by hand or by mechanical rollers, to bring out the juices in the leaves that are responsible for its flavor. The rolled leaves are then fired to dry them. The entire process of rolling and firing is repeated several times until the leaves are completely dry. The process of producing green tea is very exacting because variation in the drying time can result in fermentation of the leaves which spoils its flavor.
Herbal Tea Herbal tea has been in use since a long period of time. It is also known as a herbal infusion or tisane. Herbal tea is basically the mixing of dried fruit, flower or herb in boiling water. It is natural, free of caffeine free. There is no artificial coloring or flavors. A mixture of aromatic, carminative, sedative, expectorant herbs, which have their own importance, it has lot of beneficial effect on health, body and mind. It is gaining popularity due to its multi effects. Herbs are used in their natural forms and these herbs are without any chemical treatment. There is nothing like a cup of delicious herbal tea to nourish and soothe the body and mind.
Lemongrass Tea Lemon grass is also known as Cymbopogon citratus, and has certain therapeutic properties and the reported benefits of using it internally, in the form of a herbal tea (infusion) are reducing fevers, stomach cramps, flatulence and colic, easing arthritic pain, general digestive aid . It is especially suited for digestive problems in children. Lemon grass is commonly used in teas, soups, and curries. It is also suitable for poultry, fish, and seafood. It is widely used as a herb in Asian (particularly Vietnamese, Hmong, Khmer, Thai, Lao, Malaysian, Indonesian, Philippine, Sri Lankan) and Caribbean cooking. It has a citrus flavor and can be dried and powdered, or used fresh. Dried lemon grass leaves to make a zesty, refreshing drink that is highly satisfying both hot and cold.
Moringa Green Tea There is an old saying: "Moringa leaves prevent 300 diseases." Moringa green tea set the free radicals, purifies blood, reduces stress of smokers and alcohol drinkers. Indeed, induces No-Smoke temptation. Dead cells of the skin are removed and improves glows and shine. It is highly beneficial for pregnant women, lactating mothers and working women for its soothing powers. Downloaded from www.icbse.com
Regular consumption of Moringa Green Tea keeps people consuming it in refreshing mood and keeps their body fit with improved performance and memory. This is due to cleaning effect of Moringa Green tea. This is an organic product and cultivated in a natural environment, under the vigilance of horticultural experts.
Organic Tea Dr. John Weisburger, Director Emeritus, American Health Foundation tells about organic tea that “Current research shows tea contains specific antioxidants & health promoting ingredients. Lowering the risk of heart disease, stroke & certain types of cancer link, pancreatic and prostrate." The greatest organic tea benefit is the presence of polyphenol oxidase - an abundant supply of antioxidants. They can be termed as the “true elixir” of life. The activity of antioxidants in tea is more than that in over 21 fruits and vegetables. Tea qualifies as organic only when environment-friendly techniques are used in its production. Demand for organic tea, like other organic foods, has also been growing rapidly.
Orthodox Tea The top two leafs of each tea plant is the orthodox tea. It is said that these leaves produce the best quality tea leaf and since even today, leaves are plucked by hands, we ensure that we collect only these leaves to make our orthodox tree. The demand for orthodox tea is rising worldwide even as India produces a meagre 80 mkg of this tea annually out the total production of more than 900 mkg. Although Orthodox Tea is somewhat similar to Green Tea, it requires even finer tea leaves than the latter. It is sold domestically through auction centers and is exported in small quantities overseas.
Slimming Tea Slimming tea is known to help digest fatty foods. Made of natural herbs, such tea increases metabolism and help to reduce your cholesterol levels. It suppresses the appetite, detoxify, cleanse and rid the body of excess fat. Such tea does not cause you diarhea, instead they treat obesity from the root. Such tea can also be used for coronary heart diseases. It also reduces blood sugar levels. Consuming this tea also reduces stretch marks and melts cellulite naturally. Overweight patients suffering from a feeling of heaviness, fatigue, and body pain have also experienced relief on consumption of this tea. Slim tea also helps clear up body channels.
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The Health Benefits of Tea The main advantage of tea lies in the fact that it is a completely natural product, without any added flavorings, colors or preservatives. Likewise, when drunk without adding any sugar, honey or milk, tea has no calories and simultaneously serves as a crucial component for maintaining the balance of body liquids.
Research into the Health Benefits of Tea •
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Tea leaves contain a high amount of polyphenols, which are a type of antioxidant, and that regular consumption of about five cups of tea per day contributes to keeping a high level of them in the bloodstream. The antioxidants work to neutralize free radicals. The free radicals are oxidizing molecules which naturally and harmlessly exist within the human body. However, they accumulate as a result of physiological processes such as metabolism, and are furthermore found in environmental factors such as polluted air, poisonous waste and cigarette smoke. Tea prevents the rise of homocysteine which is known to be an important and significant risk factor for cardiovascular diseases, due to the content of vitamin M in tea. The vitamin M, which is a B complex vitamin, assists in preventing cancer and it also plays an important part in the health of the nervous system, the eyes and other systems. Tea leaves contain fluoride which helps strengthen bones and teeth and fights cavities. Tea believed to boost the body’s defenses A green tea component helps kill leukemia cells Drinking tea might delay Alzheimer's Disease Tea may play a role as an AIDS fighter
Tea and Caffeine Caffeine is a natural substance found in numerous plants. Its consumption helps with metabolism, weight loss and vitality. The average amount of caffeine from brewed tea leaves depends on the type of tea (black tea contains more caffeine than green tea), the brewing duration, and the water temperature (the higher the temperature- the greater the amount of caffeine drained from the leaves). A healthy individual can consume up to about 350 mg of caffeine per day without any concern. Caffeine content per serving (milligrams) Brewed Tea
8 oz. Serving
Black tea
40
Green tea
40
Iced tea, ready to drink
30
Iced tea mix, unsweetened
13
Bottled Tea
8 oz. Serving Downloaded from www.icbse.com
Nestea Lemon Sweet
11
Lipton Brisk, All Varieties
6
Harmful Effects of Tea Harmful effects of Caffeine When taken before bedtime, caffeine can interfere with getting to sleep or staying asleep. Exactly how caffeine will affect an individual? And for how long, depends on many factors, • The amount of caffeine ingested • Whether one is male or female • One's height and weight • One's age • Whether one is pregnant • Whether one smokes Caffeine is converted by the liver into substances that are excreted in the urine. Some people are more sensitive to the effects of caffeine than others. With frequent use, tolerance towards many of the effects of caffeine will develop. At doses of 600 milligrams (about six cups of coffee) or more daily, caffeine can cause nervousness, sweating, tenseness, upset stomach, anxiety , and insomnia. It can also prevent clear thinking and increase the side effects of certain medications. This level of caffeine intake represents a significant health risk. Caffeine can be mildly addictive. Even when moderate amounts of caffeine are withdrawn for 18 to 24 hours, one may feel symptoms such as headache, fatigue, irritability, depression, and poor concentration. The symptoms peak within 24 to 48 hours and progressively decrease over the course of a week. To minimize withdrawal symptoms, experts recommend reducing caffeine intake gradually.
Harmful Effects of Drinking Excessive Tea People drink tea to relax. A sizzling cup is refreshing. Yet, excessive tea is not advisable. It is harmful to health. It slowly affects the body systems. The habit of drinking too much tea should be avoided. Tea is prepared from leaves of shrub belonging to camellia family. The plant is a native of south East Asia. The earliest record of its cultivation comes from China in 4th century AD. The chemical composition of tea leaves are as follows: Moisture: 5 – 8% Aromatic oils: 0.5% Downloaded from www.icbse.com
Caffeine: 2.5 – 5% Nitrogen: 4.75 – 5.5% Soluble substances: 38 – 45% Tannin: 7 – 14% Minerals: 5 – 5.75% The primary effects of tea are due to alkaloids, caffeine, tannin and aromatic oils. It is not only composition of tea leaves that is harmful but also the composition of infusion which is prepared by boiling tea with water. The harmful effects of drinking excessive tea in case of specific diseases are as summed below: Indigestion: Tea is said to slow down digestion. It impedes the action of ptyalin, a digestive ferment of saliva which acts as cooked starch. Tannin is responsible for inhibition of this condition. This effect could however disappear once milk is added as milk precipitates tannin. Tea also delays stomach digestion and could lead to gas formation diarrhoea and constipation. Kidney disorders: Experiments show that 5 cups of tea increases the urine by 400 – 500% in people vulnerable to kidney related ailments. This continued stimulation of kidneys by caffeine might damage them. Tea could also promote kidney stone because of its high concentration of oxalate. Premenstrual syndrome: Drinking tea could aggravate symptoms of premenstrual syndrome. According to a research conducted under Dr Annette Rossignol, an associate professor of public health at Oregon University, women in China who drank between 1 – 4 cups of tea a day were twice as likely to have PMS then non tea drinkers. Drinking 8 cups of tea increased the PMS occurrence 10 times. Incontinence: Drinking too much tea could lead to incontinence or frequent/urgent impulse to urinate. According to a recent study conducted at St. George’s Hospital London, caffeine could exert pressure on bladder by causing muscle surrounding it to contract increasing the need to urinate. The respiratory and cardiac muscles are also stimulated by caffeine as coronary arteries get dilated resulting in the increase in the rate of blood flow. The quickening of respiration lowers the level of carbon dioxide and increases the heat production of body by 10 – 20%.
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Ceremonies and Cultures China - The Original Tea Ceremony The Chinese tea ceremony is the most ancient ceremony and plays a central role in Chinese culture. The tea is the heart of the ceremony: the host and ceremony participants smell the tea, taste it and enjoy the many layers of taste discovered with every mouthful. The tea ceremony reflects the search for beauty in every object of the world, in accordance with the Chinese Tao philosophy. The ceremony must be conducted in a peaceful atmosphere and induce a sense of tranquility and harmony among the participants. The tea ceremony is conducted for various purposes: anything from expressing appreciation or asking forgiveness, to creating goodwill among the guests of family reunions or wedding celebrations.
Japan - Motifs of Harmony and Aesthetics The tea ceremony is conducted in the "tearoom", which every traditional Japanese house has. The tearoom is considered to be an island of tranquility and purity, allowing the guests to leave the outside world behind and relax. Artistic motifs influenced by Japanese architecture, drawing and sculpture, are interwoven into the tea ceremony and influence the design of the tearoom and the ceremonial tea dishes. The modern Japanese culture considers tea to be a social drink and gives it a central role in their lifestyle, but the traditional tea ceremony is almost never conducted any longer in daily life. The tea ceremony holds a place of honor in Japanese culture as a magnificent trace of the past. There are currently three tea schools in Japan, established 300 years ago, which continue to bequeath the art of tea and Japanese hosting.
Russia - Samovar And Strong Tea
At the beginning of the 17th century, the Chinese Emperor presented the Russian Czar with a gift of tea. Tea culture is an integral part of Russian Downloaded from www.icbse.com
culture and is referred to in works of art and literature. The samovar, a metal container for heating water, can be found in almost every home and is part of the Russian cultural icons. The Russians tend to prepare a strong, bitter concentrate of black tea which is kept in a small teapot next to the samovar. The concentrate is diluted with boiling water to prepare tea according to the drinker's preferred strength.
Great Britain - Tea With Milk
The British are among the world's most massive tea consumers. Perhaps it is possible to understand the importance of tea in British culture if we recall Sir Winston Churchill's declaration during the Second World War that: "Tea is more important to the soldiers than munitions". Black tea was very common in Britain during the 18th century and the British founded the tradition of adding milk to black tea.
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Contents of Tea 1. Tannic Acid 2. Polyphenol 3. Caffiene
1.
Tannic acid
Synonyms: Gallotannic acid, Gallotannin, Galloylglucose, Glycerite, Quebracho, Tannins Molecular formula Molecular Weight Melting Point Flash point Water Solubility
: : : : :
C76H52O46 1701.22 218 °C 198 °C 250 g/L (20 °C)
Properties:
Tannic acid has anti-bacterial, bacterial, anti anti-enzymatic and astringent properties. Tannic acid has constringing action upon mucous tissues such as tongue and inside of mouth. The ingestion of tannic acid caused constipation and can be used to treat diarrhoea (in thee absence of fever or inflammation). The anti antioxidant and anti-mutagenic mutagenic properties of tannic acid are beneficial. Externally, tannic acid is used to treat ulcers, toothache and wounds. Facts about Tannic Acid:
Tannic acid is also used in many industrial applications. The best known is the tanning of leather. Tannic is acid is sometimes used to clear wines. Tannic acids reacts with proteins in wine to form insoluble complexes which sediment or can be filtered. Description:
Tannic acid is a polymer of Gallic acid molecules and glucose. It the example there are 3 Gallic acid molecules, but normally there are about 8. Because there are different molecular structures for tannic acid it would have been better to speak about tanni tannicc acids (in plural). Tannic acid will hydrolyze into glucose and Gallic or ellagic acid units. Tannic acid is odorless but has a very astringent taste. Pure tannic acid is a light yellowish and amorphous powder powder.
2.
Caffiene
Synonyms: 1, 3, 7-Trimethylxanthi nthin Molecular formula Molecular Weight Water Solubility
: C8H10N4O2 : 194.19 94.19 gm/mol : 2.17 g/100 ml (25 °C) 18.0 g/100 ml (80 °C) 67.0 g/100 ml (100 °C) Downloaded from www.icbse.com
Properties:
Caffeine acts on the nervous system by blocking adenosine receptor thereby slowing down nerve cell activity. Caffeine stimulates the central nervous system, respiration and blood circulation. Caffeine also acts as a diuretic. Caffeine increases the circulation and oxidation of fatty acids. This is why caffeine is used by sportsmen to increase fatty acid metabolism. Caffeine is often used in combination with aspirin to treat headaches. Facts about Caffeine:
from caffeine containing plants was used to treat headaches, coughs and even plague. Only recently caffeine is used to stay awake and relieve fatigue. Caffeine is now one of the most widely used phytochemical. Description:
Caffeine is a water-soluble alkaloid. Pure caffeine is a white odorless crystalline powder with a very bitter taste. Caffeine is closely related to other alkaloids such as theophylline (mainly found in tea) and theobromine (mainly found in cacao beans). Distribution:
Caffeine is found in many everyday products, including tea, cola nuts, coffee, chocolate, mate and guarana. It is also found in some soft drinks (mainly colas and energy drinks) where it is artificially added.
3.
Polyphenol
Tea polyphenol is one of the main ingredients in tea and takes up 12-24% of the tea. Drinking a cup of polyphenol-enriched oolong tea with a high fat meal may increase the amount of cholesterol excreted by the body by half, says a small study from Japan and Taiwan. The health benefits, which have mainly focused on green tea, have been linked to the polyphenol content of the tea. Green tea contains between 30 and 40 per cent of water-extractable polyphenols, while black tea (green tea that has been oxidized by fermentation) contains between 3 and 10 per cent. Oolong tea is semifermented tea and is somewhere between green and black tea. Polyphenols are most definitely antioxidants, which means that they can reduce the risk of developing coronary artery disease and a number of other health problems. Thepolyphenols found in tea have also been linked with cancer reduction, as they appear to block the action of some enzymes linked with cancer. The polyphenols found in tea also appear to suppress the growth of harmful bacteria, while promoting beneficial bacteria in the gut.
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Experiment 1 Compare the water soluble polyphenol (catechin) content in the various samples of tea leaves. Bunsen burner, tripod stand, wire gauge, beaker, funnel, filter paper, chemical balance Tea contains upto 30% of the water soluble polyphenols (catechin). These are largely responsible for the flavour if the tea. To estimate the extent of these compounds in a given sample, the tea leaves are immersed in hot water for equal time and the loss in the weight of tea leaves is determined. 5gm of 3 different tea leaves. Distilled water.
Aim: Materials Required Theory:
Things Required: Chemicals Used: Procedure:
1. Weigh exactly 5gm of 1st sample of tea leaves. 2. Take 100ml of distilled water in a beaker. 3. Put tea leaves in above beaker and boil it for 10 minutes. 4. Filter above boiled solution using funnel and filter paper in another beaker. Store the residue aside and them dry. 5. Weigh the dried residue. 6. Repeat the above 1-5 steps for the other two samples. Observations: S.No. Brand Name of Tea
Initial Weight (x gms)
Final Weight (y gms)
Loss of Weight
% of water soluble component = (y/x)*100
1. Red Label 2. Honey Gold Tea 3. Taza Tea Result: The tea having better flavour has more polyphenol content.
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Experiment 2 Compare the tannic acid content in the various samples of tea leaves. Bunsen burner, tripod stand, wire gauge, beaker, funnel, filter paper, chemical balance The tannic acid present on the tea leaves is precipitated as calcium tannate by treatment of aqueous solution of tea with Calcium Carbonate. Calcium tannate is the hydrolysed with conc. H2SO4 and recrystallized from water. 5gm of 3 different tea leaves. Calcium Carbonate (CaSO4).
Aim: Materials Required Theory:
Things Required: Chemicals Used: Procedure:
1. Weigh exactly 5gm of 1st sample of tea leaves. 2. Take 100ml of distilled water in a beaker. 3. Put tea leaves in above beaker and boil it for 10 minutes. 4. Filter above boiled solution using funnel and filter paper in another beaker. 5. In filtrate add 2gms of CaCO3 and boil it. 6. Filter above boiled solution using funnel and filter paper in another beaker. There will be a ppt. of Calcium tannate on the filter paper. 7. Keep filter paper aside and let it dry. 8. Weigh the ppt. of tannic acid. 9. Repeat the above 1-8 steps for the other two samples. Observations: S.No. Brand Name of Tea 1. Red Label 2. Honey Gold Tea 3. Taza Tea
Weight of tea leaves taken(x gms)
Weight of tannic acid obtained (y gms)
% of tannic acid= (y/x)*100
Result: The tea sample containing higher percentage of tannic acid gives better flavour.
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Experiment 3 Compare the caffiene content in the various samples of tea leaves. Bunsen burner, tripod stand, wire gauge, beaker, funnel, filter paper, chemical balance, conical flask, cork Tea containd caffiene upto 4%. It is more soluble in chloroformthan in water. 5gm of 3 different tea leaves. dilute H2SO4, Cloroform.
Aim: Materials Required Theory: Things Required: Chemicals Used: Procedure:
1. Weigh exactly 5gm of 1st sample of tea leaves. 2. Take 100ml of distilled water in a beaker. 3. Put tea leaves in above beaker and boil it for 10 minutes. 4. Filter above boiled solution using funnel and filter paper in another beaker. 5. In filtrate add 2gms of CaCO3 and boil it. 6. Filter above boiled solution using funnel and filter paper in another beaker. There will be a ppt. of Calcium tannate on the filter paper. 7. Add 10ml of H2SO4 to the filtrate and boil it. 8. Filter above boiled solution using funnel and filter paper in conical flask. There will be a ppt. of PbSO4 on the filter paper. Discard the filter paper. 9. Add 5ml of Chloroform to it. Cork the flask and shake it well. 10. Filter above solution using funnel and filter paper in another conical flask. There will be a ppt. of Caffeine. Add 5ml of Chloroform to the filtrate. Cork the flask and shake it well. Filter the solution in same funnel. Repeat this step 4 times to extract all the Caffeine present in the solution. 11. Weigh the filter paper. 12. Repeat the above 1-11 steps for the other two samples Observations: S.No.
Brand Name of Tea
Weight of tea leaves taken(x gms)
Weight of caffiene obtained (y gms)
% of caffiene= (y/x)*100
1. Red Label 2. Honey Gold Tea 3. Taza Tea Result: The tea sample containing higher percentage of caffiene gives better flavour.
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Bibliography 1. http://www.inpursuitoftea.com/ 2. http://www.icbse.com
Some good books on tea: Tea: bioactivity and therapeutic potential
By Yong-su Zhen
Healing teas: how to prepare and use teas to maximize your health The book of tea
By Marie Nadine Antol
By Kakuzō Okakura
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