How much caffeine is there in tea ?
Caffeine content in tea is negligible, when compared with most  carbonated beverages, coffee etc. The human body requires a certain  amount of caffeine and research indicates that upto 10 - 12 cups of tea  daily, will not have any detrimental effect on the body. The species or  the variety of the tea plant determines content of caffeine in tea, as  it is a genetic feature. Camellia Sinensis, the variety that is grown in  Sri Lanka has caffeine levels of approximately 2.5 - 4%. However the  distribution of caffeine in the plant depends the part of the plant it  is derived from.
For example : Bud   4.70 % First leaf 4.20 % Second Leaf 3.50  % Third Leaf 2.90 % Upper stem 2.50 % Lower stem 1.40 % Caffeine is one of the three Methylxanthines in tea and  represents the bulk of this component. As caffeine is a water-soluble  compound approximately 80% of caffeine is extracted during the brewing  process. Caffeine content in brewed tea varies depending upon the blend,  the brewing time and the brewing method. Research has revealed that a  170- ml (6-oz) serving of tea contains, on average 34 mg of caffeine in  comparison to 99 mg of caffeine in a 170 ml serving of brewed coffee and  37mg in 56g of a dark chocolate bar.

How much caffeine is  considered safe ?

The  Food Guide to healthy eating recommends caffeine consumption in  moderation. According to the current findings for most people an intake  of caffeine up to 400-450 mg per day does not increase the risk of heart  disease, hypertension or have an adverse effect on pregnancy or the  foetus. This level of caffeine is equivalent  to approximately 10 to 12 cups (170 ml) of tea per day.

Does green tea have the same Caffeine level as black tea ? Green tea, as well as Oolong tea & Black tea, are produced  from the herb Camellia Sinensis. They all contain the same amount of  caffeine. Caffeine content in a cup of tea is 2.5% to 4%, which is about  a third of that in coffee. It is claimed that 80% of the caffeine in tea  remains unabsorbed by the human body. From the above you would realise that Green tea, Oolong  tea & Black tea may taste different but the caffeine content is the  same.

Why should one never reboil water when brewing tea ?

Taste, colour  and mouthfeel depend on the interaction between the two main components  of tea, polyphenols and caffeine. Each component is astringent on its  own, but as a complex the astringent character is reduced.
Water is known to contain gases absorbed from the air.  Carbon dioxide (CO₂) gas that is present in water effects the  acidity.
Acidity of water plays a critical roll in the  ionization of tea polyphenols and it contributes to the stability of the  above complex.
CO₂ in water is gradually released during the boiling  process. Re-boiling will in fact further reduce CO ₂ levels,  resulting in a decrease in the acidity. As mentioned above this will  effect the caffeine and polyphenol complexion, and bring about changes  in the colour as well as the character of the brew.

Twice boiled water will therefore affect the taste of a  good tea and hence our request that only freshly boiled water is used  for brewing Dilmah tea.

Does drinking tea during pregnancy affect the foetus? Questions surrounding caffeine intake and risk of miscarriage  and health of the foetus continue to be raised by pregnant women. A study published in the journal of American Medical  Association found no evidence that moderate caffeine use increases the  risk of spontaneous abortions, growth retention or account for other  factors. Another seven-year epidemiological study on 1,500 women  examined the effect of caffeine, during pregnancy as well as on  subsequent child development. Caffeine consumption equivalent to approximately 3 ½ to 5  cups of tea per day had no effect on birth weight, birth length and head  circumference of the baby. A follow-up examinations at age's eight  months, four and seven years also revealed no effect of caffeine  consumption on the child's motor development or intelligence.

A number of factors influence the metabolism of caffeine and the  individual's response to caffeine indigestion. These include pregnancy,  age, sex, body weight, diet, exercise, and stress smoking and alcohol  consumption.

Pregnancy hampers caffeine metabolism. For example, in non pregnant  women the break-down of half of the caffeine takes an average of 2.5 -  4.5 hours, 7 hours during mid-pregnancy and 10.5 during the last few  weeks of pregnancy. As caffeine retention is longer during pregnancy,  women sensitive to caffeine may be affected. As a result a moderate  consumption of approximately 3-4 cups a day, is recommended for women  during pregnancy.

What is decaffeinated tea ?

For  teas to be labelled decaffeinated, the caffeine content should not  exceed 0.4% by dry weight, which is equivalent to approximately 4 mg of  caffeine per 170 ml serving.

The process of decaffeination extracts the caffeine in tea. The  current commercially available methods for decaffeinating black tea are  solvent based extraction using ethyl acetate or methylene chloride, and  extraction using supercritical (solid) carbon dioxide. All three methods  extract caffeine with minimum effect to the quality of tea.

Tannic acid what is it and is it present in tea ?

 

Tannins or tannic acid are not present in tea. Tea polyphenols  were formerly referred to as tannins or tannic acids due to the  similarities in the chemical structure. This has left many misguided  notions about the effect of tea upon the human digestive system.  Chemists generally group compounds into 'families' on account of common  features in the synthesis of the molecules. For example both strychnine  and morphine are alkaloids and have common structural features but the  action on the human body is different. Strychnine is a powerful  stimulant and morphine a powerful hypnotic. Vegetable tannins are a large chemical family and some of them are  loosely called tannic acids. These compounds possess the property of  hardening animal tissues and turning hide into leather. Tea polyphenols  on the other hand are called catechins, theaflavins and thearubigens,  and are responsible

for many of the health benefits associated with tea.  Such as anti-hypercholestemic action, anti-hyperglycemic action, fat  reduction action, anti-hypertensive action, anti- cancer action and many  other health promoting effects. Current scientific literature points to  the fact that tea polyphenols are biochemically very different to  tannins.

What are the nutritional  benefits of tea ?

Tea  composition varies with climate, season, horticultural practices and  variety. Polyphenols are the most important component in tea, as they  constitute approximately 36 percent of the dry weight of tea. Other  components of fresh green leaf include caffeine, protein and amino  acids, carbohydrates, lipids, vitamins and minerals.

Green and black tea have similar chemical make-up. The  primary difference between the two types lies in the chemical changes  that take place during their production. In black tea the plant  Polyphenols are oxidized and this is prevented in the manufacture of  green tea.

One of the most important groups of Polyphenols in tea is the  catechins in green tea, theaflavins and thearubigens in black tea. A  variety of physiological effects have been attributed to tea catechins  which are currently best known for their antioxidant activities.

Black tea is all-natural (non flavoured) and contains no additives.  It is virtually calorie-free (1 calorie per 100 ml) and sodium free and  is therefore a suitable beverage for individuals on calorie-reduced or  low sodium diet.  Tea includes fluoride, traces of vitamins A, K,  C, B carotene and B vitamins.

 

Average daily consumption of tea in the United Kingdom, 3.43 cups  (650 ml), provides very few calories and only a small amount of fat,  whilst contributing valuable minerals and vitamins to the diet. It  provides: Over half of the total intake of dietary flavonoids. Nearly 16% of the daily requirement of calcium Almost 10% of the daily requirement of zinc Over 10% of the folic acid need Around 9%, 25% and 6% of vitamins B1, B2 and B6 respectively.

Does tea affect the absorption of Iron ?

Although concerns have been expressed about consumption of iron,  existing research and dietary knowledge indicate that tea is not likely  to cause health risk, in individuals consuming a typically Western diet.

Dietary iron exists in two forms, heme iron (derived from animal) and  non-heme iron (found in plants). The body better absorbs heme iron than  non-heme iron. Between 15-35 % of heme iron is absorbed, while 2-20% is  absorbed of non-heme iron. Non-heme iron is generally modified by other  dietary components.

Certain components in grain, fruit and vegetables as well as  polyphenols in tea reduce the availability of iron to the body. However,  studies have shown that tea only decreases iron absorption when it is  consumed simultaneously with food containing non-heme iron. Tea drinking  between meals has no effect on iron absorption.

Moreover the ability of tea polyphenols to decrease iron absorption  is reduced by the presence of other dietary constituents particular  ascorbic acid (known to increase absorption of non-heme iron) and milk.

What are antioxidants ?

Antioxidants are components which help to protect cells from  harmful "free radicals", known as oxidants. Free radicals occur  naturally in the body as a by-product of the respiration process and can  bring about cell damage. Antioxidants help to prevent this cell damage,  which can contribute to ageing and a number of chronic diseases,  including cancer and heart disease and strokes.

Are the antioxidants in green and black tea the same ?

 

Green tea and black tea have similar but not identical chemical  components. Despite the differences in chemical composition, both  contain antioxidants called polyphenols and latest research evidence  suggests both have similar biological effects. Green tea contains  antioxidant compounds known as catechise while black tea contains  theaflavins and thearubigens, which are polymerised from catechins.

Green and black tea comes from Camellia sinensis. Green tea is  steamed immediately after plucking and retains a lighter colour and  flavour. Black tea is allowed to oxidise and is then dried, resulting in  a darker leaf colour and a more flavour and aroma.

Can tea be part of a healthy adult's daily fluid  intake ?

As  brewed tea contains almost 98% water it makes a healthy contribution to  the delay fluid balance. Tea contains no additives or artificial  colours. Research indicates possible antioxidant benefits so drinking  tea can be a calorie-free way to increase intake dietary  antioxidants.

Does tea reduces the diuretic  effect in comparison to  coffee ?

The  diuretic can be attributed to the caffeine present in tea and coffee.  Caffeine increases diuretic action on the kidneys, increasing urinary  volume and sodium extraction as a result of a decrease in the tubular  re-absorption of sodium and water.  Coffee contains a higher  content of caffeine compared to tea. Research has shown that a 170ml  (6-oz) serving of tea contains, on average 34mg of caffeine in  comparison to 99 mg of caffeine in 170 ml serving of brewed coffee. As a result the diuretic effect of coffee is greater compared to tea

Why does tea cloud when it  is cooled ?

Clouding in tea is a result of the colloidal precipitate that is  formed. This is called 'tea cream'. Tea creaming takes place when black  tea is cooled below 400 C. A weak complexion is formed  between caffeine and polyphenols (theaflavins and thearubigins). The  tendency to cream down varies from tea to tea. In black tea without milk  complexation and subsequent precipitation that occurs is negligible due  to just 4% of caffeine.

In tea with milk a similar association takes place between  the milk protein casein and various polyphenols. Due to the availability  of casein in milk tea the complexion is greater resulting in larger  precipitation.

Does the water effect  the tea brew ?

The  water used to brew the tea significantly affects the colour and the  taste of a cup of tea. Tea brewed in soft water or permanently hard  water (which contains CaSO4) appears brighter than if it is  brewed in temporary hard water (that contains Calcium bicarbonate  CaCO3). High pH water that contains bicarbonate makes the infusion look  darker brown due to the greater ionisation of the tea polyphenols. While  lower pH as in lemon tea the infusion turns yellow. As for taste some  teas are more suited to softer water such as the orthodox

manufactured  Assam leaf, while high grown Ceylon and CTC manufactured teas are better with temporary hard water.

What is tea scum or the  dark skin on top of the brewed tea ?

It  is the result of the high molecular weight components which are formed  due to the influence of calcium and bicarbonate ions at the liquid water  interface. The scum can  be removed in two ways

1) by filtering the calcium ions,

2) by adding acids to covert bicarbonate ions to CO2 .

Very little scum is formed on a cup of very strong tea. As  the acidic tea polyphenols themselves partly neutralise the bicarbonate  ions. It also should be noted that less than one mg of scum is formed in  a cup of tea and it is not known to be harmful to human health.

Can overcooked water effect the quality of  tea?

Boiling water for too long does dramatically affect the quality  of tea. The desirable brisk taste of tea is created by the interaction  of two of its main components, caffeine and polyphenols. Each component  is harsh on its own but as a complex the compounds moderate each other.  Acid levels of water affect the behaviour of these components.

Water contains minerals and gases absorbed from the earth bed and  air. Carbon dioxide absorbed by air makes the water slightly acidic that  influence the colour and taste. High temperature changes the acidity of  water and the acidity is reduced by gradually driving out  carbon-dioxide. Therefore re-boiled water might well brew tea of a  different colour and strength and is unsuitable to brew a good cup of  tea.

Herbal Infusions, fruit based tisanes and floral infusions are not  tea. There are only three types of tea, black tea, green tea and Oolong  tea. In many countries, notably the USA, these infusions are usurping  the health and other benefits of tea falsely. We give below a brief  introduction to the most popular herbal infusions. Dilmah offers a  selection of three herbal infusions, clearly differentiated from Dilmah  black and green teas.

CHAMOMILE (Chamomillae romanae)

Chamomile herbal infusions are derived from the plant  Chamomillae romanae. It is a one-year plant, which reaches a height of  approx. 55.cm. Chamomile contains 0.6% - 2.4% essential oils such as  angeloyl, methacryl and flavenoids as the main constituents. The white  flower heads are mechanically harvested and dried in chambers to  manufacture the commercial product.

Chamomile was known for its health benefits for centuries and the  ancient Egyptians dedicated it to their sun god, and used Chamomile in  their aromatherapy. This legacy of Chamomile lives on. Studies have that  it is beneficial for complaints such as indigestion, nervousness,  depression and headaches.

In testing its Chamomile based product Kamillosan, the Chemiewerke  Hamburg Pharmacy of West Germany found that it reduces gastric acid and  helps prevent ulcers. It also promoted tissue regeneration after  patients had operations on their intestinal tract and urinary system.  Chamomile decreases histamine, implicated in ulcers and the skin  swelling, puffy eyes and headaches brought about on by allergies. It is  given to children for digestive and hyperactive problems.

The Greeks named Chamomiles  "kamai melon" (ground apple)  inspired by its distinct apple like fragrance and the Spanish called it  Manzanilla or "little apple".

PEPPERMINT (Mentha piperita  L.)

Peppermint originated from the Mediterranean but is now  cultivated globally in the Balkans, Northern Europe and the USA. It is  characterized by its strong aroma. It is a perennial herb with a flat  root system. It reaches normally a height of approx. 2-ft and is  harvested shortly before blooming. Peppermint contains 0.5 4 %  essential oil that includes Menthol and menthol esters. Written evidence of old Egypt indicates that Mentha plants  were cultivated and exploited for medical use 1,000 years before  Christian era.  It also shows that Mint plants have represented a  valuable object of trade, and was even accepted as tithes to pay taxes  due.

Studies have shown that peppermint tea brings about considerable  increase in the production of bile due to the presence of flavonoids.  Peppermint leaf or extracts prepared from it are included in many (ca.  50) prepared cholagogues and bile-duct remedies, e.g. Cholagogum  Nattermann (capsules, drops), etc. gastrointestinal Remedies (ca 50),  e.g. Gastricholan Iberogast Ventrodigest, etc.), liver remedies (more  than 10), hypnotics/sedatives (more than 10), e.g. Nerventee Stada,  Esberi-Nervin drops, etc., and laxatives.

ROSEHIP & HIBISICUS

Usually consists of 70% Hibiscus and 30 % Rosehip. Hibiscus  (Hibisci flos) originated in Angola but is now cultivated throughout the  tropics. It is an annual herbaceous plant with lobed leaves that grows  to a height of 5 m. Flowers with a 5-lobed calyx and divided epicalyx.  Hibiscus for infusions is manufactured form the dried calyxes harvested  from the fruit of the species.

It is principally taken as a caffeine-free refreshing drink taken in  large amounts because of the plant acids. The plant acids which are  difficult to absorb act as a mild laxative.

Hibiscus has been extensively used in the African Folk medicine. The  drug is ascribed, among other things, spasmolytic, antibacterial,  cholagogic, diuretic and anthelmintic properties. Studies have shown  aqueous extracts of hibiscus flowers relaxes the muscles of the uterus  and to lower the blood pressure. 

Rosehip is derived from the plant Rosae pseudofructus. It is a shrub  that grows up to a height of 5 m with thorn branches with flowers close  to 5 cm in diameter with five petals.  The drug consists of the  dried hypanthia from various species of the genus Rosa with the fruit  enclosed in them. Rosehip is native to Europe, Western and Central Asia,  and North Africa but now it is cultivated in Chile, Bulgaria, Romania,  China and Hungary. It was used in folk medicine as a result of its  diuretic and laxative action due to the

pectin and the plant acid  content. Due to its high content of vitamin C Rosehip are used as  breakfast teas.

Green Tea, Oolong tea,  Black tea, Decaffeinated, Green tea component of Jasmine tea and Organic  tea are derived from the tea  plant, Camellia sinensis.

Jasmine (Jasminum officinale)

Composition includes 98% Green tea (Camellia sinensis) and  2% Jasmine flowers.

Organic tea
The manufacture of organic tea is carried-out  without the addition of Chemical fertiliser, Pesticides and Insecticides  as a result the product doesn't contain chemical residues which can  bring about health effects.