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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 made tea, 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 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.
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 %
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."
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.
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.
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 development 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-ß-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 sinensis 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 ß-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- ß-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.
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 E-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.
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 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
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.
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.
When Tea is not TEA
Green Tea, Oolong tea, Black tea, Decaffeinated Black &
Green Tea, the Green tea component in Jasmine Green tea,
and Organic tea are derived from the tea plant, Camellia
Sinensis. Many brands use the word ‘tea’ loosely since
‘tea’ refers only to the dried leaves of the plant
Camellia Sinensis, and does not include infusions like
Rooibos, Mate, Fruit and other herbal infusions. The
term Red Tea, recently associated with Rooibos, for
example refers to the herb from the South Africa shrub
Rooibos (meaning Red Bush).
The traditional forms of tea are White Tea (see below
for details), Green Tea (unfermented), Oolong Tea
(partially fermented) and Black Tea (fully fermented).
These offers the health benefits associated with tea
whilst others such as Rooibos, Mate, fruit and other
infusions usually do not, although they may have their
own specific benefits. |
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