Is the quality of a large size leaf better than small size tea grades ?
The size of tea particles (known as the grade of tea) has no bearing on quality, and only influences strength. When we harvest tea leaves and make them into tea, we use the traditional, artisanal method–withering, rolling, and in the case of black tea fermenting and baking the leaf. While rolling, the leaf can become elongated and wiry, tightly curled or smaller particles which come out as OPA, Pekoe, BOP or finer Dust or Fannings grades. A single batch of good leaf can yield several of these grades and whilst they would all be good, the only difference in the size of particles would be the strength. That is related to the surface area of the leaf when brewed with hot water. A teaspoonful of Dust tea can have four times or larger surface area than the equivalent quantity of OPA, and hence offer better extraction, and thicker, stronger brew.
Why is Ceylon Tea different ?
Tea originated in China, as legend has it, 5,000 years ago; yet it was Ceylon (now Sri Lanka) that made tea famous in the 19th and 20th Centuries, as the tea that was used by almost every major tea brand. Ceylon Tea is prized for its quality which is without parallel, and its variety which is unmatched for a small island boasting dramatically different teas in different parts of its tea growing regions.
In assessing the value of Ceylon tea, some of the properties which tea experts take into consideration are appearance of the tea such as, colour of the infused leaf, as well as colour, strength, quality, aroma and flavour of the brewed liquor. The ultimate criterion of a ‘good quality’ tea is however the subjective assessment of expert professional tea tasters.
Distinguishing itself as the ‘Best in Class’ producer of tea, with a well-documented heritage in tea, Ceylon, or Sri Lanka stands out amongst tea producers. The Low Grown teas produced in Sri Lanka below 2000-ft sea level, are known for their superior leaf appearance, highly valued in the Middle East, the coppery ‘infused leaf’ and its strong & reddish brewed liquor. Sri Lankan low growns are prized for their appearance-‘uniformly black’, true to grade and devoid of fibre and extraneous matter. The High Growns, above 4000-ft sea level, on the other hand are known for their bright, coloury, brisk and aromatic liquors. High grown Ceylon teas do not share the dense, black colour of the quality low grown leaf being browner in leaf appearance, but have unsurpassed liquors ranging from light, bright golden colour to deep red.
In Ceylon, particular emphasis is laid on the quality of tea, and this is determined by a complex of parameters, the correct balance of which is the quintessence of tea character. The appearance of the leaf (dry leaf after processing) is determined by the content of chlorophyll in the young and tender leaves of the tea shoot. The relative amounts of the polyphenols present in tea, the polyphenol oxidase (enzyme), the theaflavins, thearubigins, caffeine, essential oils, sugars, amino acids in the bud and the first two tender leaves will all contribute to the quality of the brewed liquor in a positive way. Hence the importance of traditional and disciplined picking of teas in Ceylon. The best raw material handled under poor conditions of manufacture would produce a poor quality tea. It is through attention to detail in field practices as well as in manufacture, that Sri Lanka retains its position as the Best in Class’ producer of Quality Tea, considered by the Technical Committee of the ISO as the cleanest tea in the world.
How much caffeine is there in tea ?
Caffeine from natural sources has been consumed and enjoyed by humans throughout the world for centuries. The widespread natural occurrence of caffeine in a variety of plants undoubtedly played a major role in the long-standing popularity of caffeine incorporated products, especially the beverages.
The human body requires a certain amount of caffeine and research indicates that up to 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 on the part of the plant it is derived from.
- Bud 4.70 %
- First leaf 4.20 %
- Second Leaf 3.50 %
- Third Leaf 2.90 %
- Upper stem 2.50 %
- Lower stem 1.40 %
Both tea and coffee contain the methylated xanthines, caffeine, theophylline and theobromine. Brewed coffee is said to have the highest caffeine content among those dietary items containing caffeine-approx. 100 mg per cup. A 300-ml bottle of cola has 30-60-mg caffeine and approx. 37-mg caffeine is there in 56g dark chocolate bar. There are a wide variety of drug products that contain caffeine-typically 200 mg per tablet or capsule (pharmacologically active dose of caffeine). A cup of tea has approx. 28–44 mg caffeine-(FDA 1980).
The quantity of caffeine in tea, on dry solids basis, is more than the quantity of caffeine in an equal weight of dried coffee beans. However, as a result of getting more cups of tea from a unit quantity of black tea than from an equal quantity of ground coffee beans, the quantity of caffeine per cup of tea is less than the caffeine in an equal cup of coffee.
Excessive caffeine is said to have adverse effects on the human system and brewed tea has only half the caffeine levels in brewed coffee. However, it is important to note that research proves that the presence of caffeine in tea does not produce unhealthy results due to its combination with tea polyphenols.
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.
As explained by Prof. T. W. Wickremanayake (Ph D Glasgow, Visiting Research Fellow Glasgow, Wisconsin and California) the pharmacologically active dose of caffeine is 200 mg and the acute fatal dose is about 10,000 mg. Those who drink more than 5 cups of coffee or 9 cups of tea are regularly consuming 5% of the fatal dose. The T 1/2 of caffeine is about 3 hr. It is excreted quickly in urine as 1-methyl uric acid.
Prof. Wickramanayake also states the following. “There is a positive association between Myocardial infarction and heavy coffee consumption, whereas the correlation between infarction and heavy tea drinking is negative. In rats and rabbits maintained on atherogenic diets, caffeine increases serum lipid concentrations and therefore the incidence of atherosclerosis. Coffee has the same action but not decaffeinated coffee. Tea has the opposite effect to caffeine alone or caffeine in coffee. Similar results have been reported in a study of human subjects with and without heart ailments. Russian scientists have demonstrated that a course of tea consumption improved the condition of atherosclerotic patients. The alleged adverse effects of caffeine are apparently eliminated in tea either by a modification of its activity by other constituents, or by the opposing action of some anti-atherosclerotic constituent.”
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 re boil water when brewing tea ?
Taste, colour and mouth feel depend on the interaction between the two main components of tea, polyphenols and caffeine. Each component is a stringent on its own, but as a complex the astringent character is reduced.
Water is known to contain dissolved gases absorbed from the air. Carbon dioxide (CO2) gas that is present in water affects the acidity. Acidity of water plays a critical role 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 CO2 levels, resulting in a decrease in the acidity. As mentioned above this will affect 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 consumpti on 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 w eight, 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 a cetate 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.
Nutrients in tea what is in your cup of tea. and how it can affect your body ?
|Black Tea||Green Tea|
|100 ml of
|1 cup of
|100 ml of
|1 cup of
|Energykcal / kJ||1 kcal / 4 kJ||2 kcal / 9 kJ||1 kcal / 4 kJ||2 kcal / 9 kJ|
|Carbohydrates Total (g)||0.3||0.7||0.3||0.7|
|Dietary Fiber (g)||0||0||0||0|
Source: USDA National Nutrient Database for Standard Reference Release 28: Report Date:January 25, 2016 06:22 EST
Explanation of terms
|Element / Component||Description|
|1||Energy (k cal)||Calories (k cal) measure the energy content in foods. Calorie content in tea (without sugar and milk) is negligible.|
|2||Moisture||Moisture refers to the water content in food.
Processed tea leaves contain Moisture levels of 3 – 9 %. This can vary since tea is hygroscopic and can absorb Moisture after processing, during storage. Fresh Tea deteriorates with the absorption of Moisture and Dilmah Online recommends that Dilmah Tea is stored in an airtight container, in a refrigerator to retain freshness, flavour and aroma.
Please note that Tin Caddies and tea caddies made from materials that can corrode should not be used for refrigeration due to the high Moisture levels inside a fridge–tea should be in an airtight, non corrosive container that is free of odour. For example, a clean and odour free plastic, re-sealable container.
|3||Protein||Proteins are Nitrogen containing compounds which are found in all animal and vegetable cells. An essential nutrient of all living organisms. Protein intake from tea is negligible as only less than 2% is extracted into hot water. However if milk is added it contributes significant amount of the Protein requirement.|
|4||Lipid||Substances, which are insoluble in water and these include the waxes, oils and fats. Fat gets readily deposited in cell tissue. Tea contains a negligible amount of lipids and the amount extracted to water is minimal, as it is insoluble in water. As a result tea without milk and sugar is recommended as part of a low calorie diet.|
|5||Ash (Minerals)||Inorganic constituents of plants and animals, e.g. Nitrogen, Potassium, Phosphorous, Calcium, Copper, Magnesium, Manganese, Molybdenum, Boron. They are essential for the healthy growth of the plant.|
|On average about three-quarters of the dry matter in plants consists of carbohydrates. Carbohydrates are the main ingredient for animals in maintaining their body temperature. Carbohydrates consist of sugars and polysaccharides (fibrous matter). Main sugars are glucose, fructose and sucrose. Examples of polysaccharides are starch and cellulose.
Only 4 - 5% of the solids extracted by hot water are carbohydrate, allowing tea to be used in low calorie diets.
|7||Calcium Phosphorous Ferrous Sodium Potassium Magnesium Copper||Tea contains 4 - 9% of inorganic matter and the composition of this fraction varies. Most of these substances are essential to health and tea contributes to their dietary intake. Most of the minerals found in tea are essential plant nutrients and a healthy Tea bush would be expected to exhibit a range of these components. Variations experienced are usually attributed to differences in soil, age of the leaf at harvest and other a gronomic factors.
Scientists have indicated that tea may be effective in treating anemia in due to its Copper and Ferrous components.
Sodium is an essential mineral for human nutrition however its intake has to be regulated in hypertension patients. In such cases the low proportion of sodiumin tea is advantageous
The tea bush tends to accumulate Magnesium, Aluminum and Fluorine. Magnesium is an essential nutrient for man but Aluminum is not known to be essential to human health. But is always present in human tissue. Studies have shown that the body may not absorb Aluminum in tea.
Potassium is an essential element for the cell functions, including cardiovascular muscle function and nerve function. Compared to other elements the Potassium content of tea is high. As a result tea provides part of the daily Potassium requirement.
Calcium and Phosphorus are essential elements for the bone development, strong bones and teeth and tea provides part of the daily requirement of these elements
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 be en 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 suit able 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
Tea flavonoids bind with iron, thereby decreasing its absorption. However, drinking tea between meals has no effect on iron absorption
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 inplants). 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. Therefore, in order to overcome any potential for reduced iron absorption, simply add milk or lemon to tea. If a meal contains milk, tomatoes, orange juice or as corbic acid of any kind, these will also balance iron absorption in a meal where tea is consumed
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 ?
It was thought until comparatively recently that green tea was the most effective antioxidant - containing tea and that green - tea catechins (the unoxidized polyphenols present in tea leaf) alone were the antioxidants giving tea its health - giving attributes. It is now well known that the theaflavins and thearubugins produced by the condensation of oxidized catechins, during the fermentation stage of black tea manufacture, are equally effective antioxidants (Leung et al 2001).
The catechins present in tea flush and as such in green tea are:
- Expressed as a % of dry weight
- Epicatechin 1 – 3%
- Epicatechin gallate 3 – 6%
- Epigallocatechin 3 – 6%
- Epigallocatechin gallate 9 - 13%
- Catechin 1 – 2%
- Gallocatechin 3 – 4%
During manufacture of Black Tea these catechins get oxidized & polymerized (condensed), for example
Epicatechin + Epigallocatechin gallate + Oxygen—> Theaflavin
The paired catechins as they appear in Black Tea are now known to be equally effective antioxidants. The body produces free radicals (FRs) under certain conditions. Carcinogens and radiation from the environment facilitates the formation of FRs. These FRs within the body cause oxidative changes to DNA (the genetic material present in all cells). Changes to DNA carry the risk of cancers. The FRs are inhibited and destroyed by the antioxidants in tea, both green and black tea.
green and black tea comes from Camellia Sinensis. Green tea is unfermented, steamed immediately after plucking, and retains a lighter colour and flavour. Black tea is allowed to ferment and is then dried, resulting in a darker leaf colour and a more flavour and aroma.
Can the consumption of tea be good for my memory as I grow older ?
Research conducted at the University of Newcastle shows that drinking tea could help improve memory and also slow the developm ent of Alzheimer’s disease.
The functioning of the brain cholinergic system, which is involved in attention and memory declines during normal aging and is further affected in Alzheimer’s disease. Current drugs for the symptomatic treatment of dementia are aimed at enhancing the associated cholinergic deficit by inhibiting acetylcholinesterase, an enzyme that cleaves the neurotransmitter acetylcholine. Butyrylcholinesterase increases in the brains of people with Alzheimer’s disease and may play a role in the progression of the disease by its ability inter alia to hydrolyse the neurotransmitter Acetylcholine. Inhibition of both these enzymes is one of the objectives in treating cognitive dysfunction associated with diseases such as Alzheimer’s disease.
During the study it was found both green and black tea inhibited the activity of the enzyme acetylcholinesterase, and also hinder the activity of the enzyme butyrylcholinesterase. It was further observed that Green tea obstructed the activity of beta - secretase, which plays a role in production of protein deposits in the brain that are associated with Alzheimer’s disease. So this study reports that tea infusions in vitro have dual anti - cholinesterase and anti - β - secretase activities relevant to the treatment of dementia.
Previous studies have shown that both green tea and black tea possess pharmacologically protective, properties such as antioxidative, anticarcinogenic, neuroprotective and hyppocholesterolaemic effects. This study indicates that Tea, Camellia sinen sis has the potential to enhance cholinergic function and therefore may have a role in ameliorating and cholinergic deficit in Alzheimer’s disease and other age related memory impairments. The effects of tea infusions on the cerebral cholinergic system and β - secretase in vivo will depend on the levels of the enzymes in the brain, the type and chemistry of the tea, infusion concentration (strength), dose (number of cups per day) and duration of consumption. It is also possible that regular consumption of tea by patients with dementia prescribed cholinesterase inhibitors may alter the effects of such drugs. Clinical and scientific investigation of the chemistry and activities of cholinomimetic and anti - β - secretase compounds in C. sinensis, and cognitive effects of tea consumption is warranted in order to establish the relevance of these novel findings to the maintenance of cognitive function in old age and in diseases such as Alzheimer’s Disease.
Tea and Oral Health: Does Fluoride in Tea has any implications on Oral Health ?
Tea plants accumulate fluoride in their leaves. In general, the oldest tea leaves contain the most fluoride. Most high quality teas are made from the bud or the first two to four leaves — the youngest leaves on the plant. Brick tea, a lower quality tea, is made from the oldest tea leaves and is often very high in fluoride. Symptoms of excess fluoride (i.e., dental and skeletal fluorosis) have been observed in Tibetan children and adults who consume large amounts of brick tea. Unlike brick tea, fluoride levels in green, oolong, and black teas are generally comparable to those recommended for the prevention of dental caries (cavities). Thus, daily consumption of up to one liter of green, oolong, or black tea would be unlikely to result in fluoride intakes higher than those recommended for dental health. The fluoride content of white tea is likely to be less than other teas, since white teas are made from only the buds of the tea plant.
It has been found that not only fluoride but the polyphenols in tea also act to reduce tooth decay. Recent studies have further revealed that tea inhibits the growth of other harmful microorganisms in the oral cavity.
Tea and Stroke
Many in vitro studies have demonstrated the anti - oxidant properties of both black and green tea, as well as the antioxidant activity of the polyphenols in tea. Further studies have shown that these anti - oxidant components of tea are absorbed into the blood circulation from the digestive tract and act as anti - oxidants in body systems. These findings indicate that tea drinking helps to reduce the risk of heart disease, stroke and cancer, common degenerative diseases.
Tea for Healthy Aging and Longevity
Researcher Dr Weisburger concludes from recent studies that six or more cups of tea per day helps healthy aging. Tea can restore elasticity to the skin, and tests have shown that it enhances memory.
In populations where regular tea drinking is a part of the lifestyle, as in Japan and India, individuals are likely to live to an advanced age in good health. Also, experimental studies indicate that animals given dietary antioxidants, including tea, live longer.
What is L-theanine ?
An Amino Acid found in plants which was first referred to by Dr. R. L. Wickremasinghe in 1978 in context of its influence on the quality of tea. Subsequent research conducted in Japan and elsewhere suggests that L - theanine facilitates relaxation and may benefit the regulation of blood pressure in humans, as well as mental clarity, concentration and the immune system. L - theanine is different to caffeine in producing a calming effect. It is the predominant amino acid component in tea and whilst the amount of L - theanine in tea depends on several factors – climate, soil and sunlight – clinical studies suggest that consuming 6 - 8 cups of tea a day would offer 200 - 400mg of L - theanine whilst it is said to be effective in doses ranging from 50mg to 200mg.
Fresh Tea in particular is likely to be rich in L - theanine and researchers recommend it, amongst other things, for coping with stress and also for increasing ‘life energy’.
Does Dilmah use plastic or polymer fibre in tea bag ?
The filter material used for Dilmah tea bags contained natural fibres such as, specially selected blend of cellulose fibres, wood pulp and abaca in some products and PLA material in some other products. Although some filter paper grades can contain a minimum amount of synthetic fibres to provide the necessary paper characteristics, the filter paper grades used by us cannot be classified as plastic material and articles covered by EU10/2011 based on the materials used and composition
- The following is relevant about our filter papers;
- They are not made exclusively of plastic
- They are not multi - layer articles held together by adhesives or other means
- They are single layer products not a multi material, multilayer material with plastic layers that can be separated.
- Paper fibres are not plastic polymers as defined by this regulation
The applicable legislation for all materials and articles in contact with food is EU/1935/2004 and this regulation defines the requirements that all materials must meet. The paper complies with worldwide food safety legislations such as EU/1935/2004, best practice guidelines for food contact packaging and legal requirements for the production of hot filtration papers. It is confirmed that there is no hazard to health for their use in a teabag application.
Is regular tea consumption good for my immune system
A Harvard Medical School study discovered that regular consumption of tea could boost the body’s defenses against infection. A component in tea was found in laboratory experiments to prime the immune system to attack invading bacteria, viruses and fungi, according to a study in the Proceedings of the National Academy of Sciences.
A second experiment, using human volunteers, showed that immune system blood cells from tea drinkers responded five times faster to germs than did the blood cells of coffee drinkers. Researchers claim that the results give clear proof that five cups of tea a day sharpen the body’s disease defenses.
In the study a substance called L - theanine was isolated from ordinary black tea. L - theanine is broken down in the liver to ethylamine, a molecule that primes the response of an immune system element called the gamma - delta T cell, considered the first line of defence against bacteria, viral, fungal and parasitic infections.
The T cells prompt the secretion of interferon, a key part of the body’s chemical defense against infection. To further test the finding, the researchers had 11 volunteers drink five cups a day of tea, and 10 others drink coffee. Before the test began, they drew blood samples from all 21 test subjects
After four weeks, they took more blood from the tea drinkers and then exposed that blood to the bacteria called - coli. The immune cells in the specimens secreted five times more interferon than did blood cells from the same subjects before the weeks of tea drinking researchers claimed. Blood tests and bacteria challenges showed there was no change in the interferon levels of the coffee drinkers.
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 affect 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 the 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
- By filtering the calcium ions,
- 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 over boiled water affect 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.
What is Real Tea ?
Tea in its true sense is defined by the International Standards Organisation (ISO) as, ‘tea derived solely and exclusively, and produced by acceptable processes, notably withering, leaf maceration, aeration and drying, from the tender shoots of varieties of the species Camellia Sinensis, known to be suitable for making tea for consumption as a beverage.
Real Tea is tea produced in the traditional, orthodox manner from the tender shoots of Camellia Sinensis. The process of manufacture, perfected over centuries is the most widespread in Sri Lanka with its drying, rolling, fermentation and baking into the form most people are familiar with – black tea, green tea, white tea. Orthodox Tea is distinct from the more recent process – CTC (or Cut, Twist and Curl) which was developed by companies seeking to offer quick colour in a teabag.
CTC teas rob tea of its soul, losing the subtlety of flavour, aroma, variety and character that Orthodox Teas are prized for. CTC consists of just 3 grades or forms, whilst Orthodox Tea produces almost infinite variety of leaf size, colour, subtlety of character and body.
Dilmah offers Real Tea from a Single Origin in its teabags and leaf tea, offering quality, flavour and richness of taste in both teabags and leaf tea.
What are Herbal Infusions ?
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 (Matricaria recutita)
Chamomile herbal infusions are derived from the plant Matricaria recutita. 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 flavanoids 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 tith es 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 & Hibiscus
Usually consists of 30% Hibiscus and 70 % 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.