Chemistry Project on Tannin Contents in Tea Leaves

Kendr iya Vidyal Chemistry a Investegatory No.2 Project Report AFS Tannic Acid Contents Submit In Tea ted By: Leaves Pushka l Roll Year: Purohit No.: -16450 XII-A 201403 2015

Index 1. ACKNOWLEDGEMENT 2. CERTIFICATE 3. INTRODUCTION 4. REQUIRED 5. EXPERIMENT 6. SNAPSHOTS 7. BIBLOGRAPHY

ACKNOWLEDGEMENT The project could have never been possible without the support of various sources. It is

extremely impossible to thank every individual who has helped me in completing this project. Some people have helped in the basic formularization and there were sources that helped me in giving the ideas a physical form/shape. I am extremely grateful to my mentor, Mrs. Mridula Chaturvedi, for her invaluable guidance in the project right from the beginning. Her vital support helped the project to take a logical and suitable shape. I take this opportunity to thank the School authorities, for extending their full support and cooperation in the project. Last but not the least; I would like to thank everyone who has offered a helping hand when required.

Pushkal Purohit XII-A Roll No.-1645003

Certificate This is to certify that Pushkal Purohit (Roll No: 1645003) student of Class XII, K. V. No. 2 AFS Jodhpur has completed the project titled. “Tannic Acid Contents In Tea Leaves” during the academic year 2014-2015 towards partial fulfilment of credit for the Chemistry Project evaluation of

AISSCE 2014, and submitted satisfactory report, as compiled in the following pages, under my supervision.

(Teacher’s Signature)

Introduction Tannic acid is a specific commercial form of tannin, a type of polyphenol. Its weak acidity (pKa around 10) is due to the numerous phenol groups in the structure. The chemical formula for commercial tannic acid is often given as C76H52O46, which corresponds with decagalloyl glucose, but in fact it is a mixture of

polygalloyl glucoses or polygalloyl quinic acid esters with the number of galloyl moieties per molecule ranging from 2 up to 12 depending on the plant source used to extract the tannic acid. Commercial tannic acid is usually extracted from any of the following plant part: Tara pods (Caesalpinia spinosa), gallnuts from Rhus semialata or Quercus infectoria or Sicilian Sumac leaves (Rhus coriaria). According to the definitions provided in external references such as international pharmacopoeia, Food Chemical Codex and FAO-WHO tannic acid monograph only tannins sourced from the above mentioned plants can be considered as tannic acid. Sometimes extracts from chestnut or oak wood are also described as tannic acid but this is an incorrect use of the term. It is a yellow to light brown amorphous powder which is highly soluble in water; one gram dissolves in 0.35 mL of water.

Advantages of TEA If you're not drinking tea yet, read up on these 10 ways tea does your body good and then see if you're ready to change your Starbucks order! 1. Tea contains antioxidants. Like the Rust-Oleum paint that keeps your outdoor furniture from rusting, tea's antioxidants protect your body from the ravages of aging and the effects of pollution. 2. Tea has less caffeine than coffee. Coffee usually has two to three times the caffeine of tea (unless you're a fan of Morning Thunder, which combines caffeine with mate, an herb that acts like caffeine in our body). An eight-ounce cup of coffee contains around 135 mg caffeine; tea contains only 30 to 40 mg per cup. If drinking coffee gives you the jitters, causes indigestion or headaches or interferes with sleep -- switch to tea.

3. Tea may reduce your risk of heart attack and stroke. Unwanted blood clots formed from cholesterol and blood platelets cause heart attack and stroke. Drinking tea may help keep your arteries smooth and clog-free, the same way a drain keeps your bathroom pipes clear. A 5.6year study from the Netherlands found a 70 percent lower risk of fatal heart attack in people who drank at least two to three cups of black tea daily compared to non-tea drinkers. 4. Tea protects your bones. It's not just the milk added to tea that builds strong bones. One study that compared tea drinkers with non-drinkers, found that people who drank tea for 10 or more years had the strongest bones, even after adjusting for age, body weight, exercise, smoking and other risk factors. The authors suggest that this may be the work of tea's many beneficial phytochemicals. 5. Tea gives you a sweet smile. One look at the grimy grin of Austin Powers and you may not think drinking tea is good for your teeth, but think again. It's the sugar added to it that's likely to blame for England's bad dental record. Tea itself actually contains fluoride and tannins that may keep plaque at bay. So add unsweetened tea drinking to your daily dental routine of brushing and flossing for healthier teeth and gums. 6. Tea bolsters your immune defenses. Drinking tea may help your body's immune system fight off infection. When 21 volunteers drank either five cups of tea or coffee each day for four weeks, researchers saw higher immune system activity in the blood of the tea drinkers. 7. Tea protects against cancer. Thank the polyphenols, the antioxidants found in tea, once again for their cancer-fighting effects. While the overall research is inconclusive, there are enough studies that show the potential protective effects of drinking tea to make adding tea to your list of daily beverages. 8. Tea helps keep you hydrated. Caffeinated beverages, including tea, used to be on the list of beverages that didn't contribute to our daily fluid needs. Since caffeine is a diuretic and makes us pee more, the thought was that caffeinated beverages couldn't contribute to our overall fluid requirement. However, recent research has shown that the caffeine really doesn't matter -- tea and other caffeinated beverages definitely contribute to our fluid needs. The only time the caffeine becomes a problem as far as fluid is concerned is when you drink more than five or six cups of a caffeinated beverage at one time. 9. Tea is calorie-free. Tea doesn't have any calories, unless you add sweetener or milk. Consuming even 250 fewer calories per day can result

in losing one pound per week. If you're looking for a satisfying, caloriefree beverage, tea is a top choice. 10. Tea increases your metabolism. Lots of people complain about a slow metabolic rate and their inability to lose weight. Green tea has been shown to actually increase metabolic rate so that you can burn 70 to 80 additional calories by drinking just five cups of green tea per day. Over a year's time you could lose eight pounds just by drinking green tea. Of course, taking a 15-minute walk every day will also burn calories.

Disadvantages of TEA 1. Caffeine Complications. It doesn't have as strong a kick as coffee, but tea does contain caffeine, which can make you nervous, jittery and nauseated and cause irregular heartbeats and insomnia. Although content varies by brand, black tea typically contains the most caffeine, oolong has moderate caffeine content, and green and white teas contain the least caffeine. Caffeine levels in tea may range from 14 to 60 milligrams per cup, which is far less than the 200 to 300 milligrams per day that MedlinePlus considers moderate intake. However, it may not take much caffeine for some people to experience negative effects. 2. Sugar Overload. Plain tea doesn't contain any sugar or calories, but many bottled iced teas on the market are loaded with both. One major brand's sweetened tea provides 50 calories per cup, while another's has 90 calories per cup -- with all of those calories coming from added sugar. Despite the calorie load, sugar has no nutritional value, and the American

Heart Association recommends that women get no more than 100 calories -- and men get no more than 150 calories -- from added sugar each day. 3. Tinted Teeth. While tea's rich color may look lovely in your teacup, you probably don't want your smile to match the hue. Unfortunately, tea can stain your teeth just like coffee, red wine and other colorful beverages. If staining is a concern, brush your teeth often -- ideally, immediately after finishing your tea. It may also help to drink water after your tea to rinse away the staining agents. 4. Iron Issues. Tea contains antioxidants called flavonoids, which provide many of the health rewards. Flavonoids, however, bind to the nonheme iron found in plant foods such as beans and vegetables as well as dairy products. If you drink your tea with these foods, therefore, your body may not be able to access some of the iron. To maximize absorption of this important nutrient, limit tea drinking to between meals only, or add a spritz of lemon to help counter the iron-binding effect.

Required Apparatus 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11.

Beaker Funnel Spatula Physical Balance Weight Box Filter Paper Bunsen Burner Tripod Stand China Dish Watch Glass Wire Gauze

Chemicals 1.

Distilled Water

2. 3. 4.

Tea Leaves Calcium Carbonate, CaCO3 Concentrated Hydrochloric Acid, HCl

Experiment Objective To estimate the percentage composition of tannic acid in sample of tea leaves.

Theory Tannic acid is a major component. It can be precipitated as white residue of Calcium Tannate. For such precipitation, aqueous solution of tea extract is treated with calcium carbonate (CaCO3).

Procedure 1. Boil 10g tea leaves in 100mL of distilled water, about 10 minutes in a 400mL beaker. Let the solution cool, and then filter it. 2. Add 2g CaCO3, to the filtrate, and boil it again. Take the residue of calcium tannate precipitated and filter it.

3. Residue of calcium tannate is hydrolysed by warming it with 5mL concentrated HCl. The crystals of tannic acid separate out. 4. Dry it and weigh it. Note down the observations.

Observations S. No.

Brand/Pa Mass of ck Tea Leaves Taken (a)

Mass of Tannic Acid Obtaine d (b)

% Tannic Acid Obtained (b/a*100 )%

1

A

10 g

344 mg

3.44%

2

B

10 g

370 mg

3.70%

3

C

10 g

396 mg

3.96%

Snapshots

Bibliography

i) The main Websites: (1) (2) (3)

https://www.google.co.in/ https://www.scribd.com/ https://www.wikipedia.org/

ii) Practical Chemistry Book