Caffeine is 236°C, point at which caffeine sublimes is

Caffeine is a naturally arising alkaloid which is found in
the leaves, seeds and fruits of over 63 plants species worldwide. It is an
alkaloid of methylxanthine family. The methylxanthines caffeine
(1,3,7-trimethyxanthine), theobromine (3,7- dimethylxanthine), and theophylline
(1,3-dimethylxanthine) can be usually found in tea leaves, cola nuts, coffee
beans, cocoa beans,  mate leaves and
other kinds of plants. While coffee and tea beverages naturally contain
caffeine and other methylxanthines, Caffeine aids as an ingredient in many
carbonated soft drinks including colas, pepper-type beverages, and citrus
beverages. Pure caffeine occurs as odorless, white, fleecy masses, glistening
needles of powder. Its molecular weight is 194.19g, melting point is 236°C, point
at which caffeine sublimes is 178°C at atmospheric pressure, pH is 6.9 (1%
solution), specific gravity is 1.2, volatility is 0.5%, vapor pressure is
760mmHg at 178°C, solubility in water is 2.17%, vapor density 6.7.Caffeine has
drawn more attention in the past decades due to its physiological effects
beyond that of its stimulatory effect. The Food and Drug Administration (FDA)
defines caffeine as a generally recognized as safe (GRAS) substance. However,
FDA specifies that the maximum amount in carbonated beverages is limited to
0.02% (FDA 2006). Therefore, the highest legal amount of caffeine allowed in a
355 mL (12oz) can of soft drink is about 71mg. Caffeine has attracted the
interest of consumers and health professionals alike due to its wide consumption
in the diet by a large percentage of the population and its pharmacological
effects in humans (Mandel 2002). The human’s saliva caffeine level, which
demonstrates the extent of absorption, peaks around 40 minutes after caffeine
consumption (Liguoriet al 1997). Its physiological effects on many body systems
have been informed by researchers, containing the central nervous,
cardiovascular, gastrointestinal, respiratory, and renal systems (Nehliget al
1992). The International Olympic Committee (IOC) defined caffeine as a drug and
abuse is indicated when athletes have urine caffeine concentrations higher than






           1.2 Caffeine

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Caffeine is a central nervous system
stimulant. It is one of the most popular drugs in the world, consumed by up to
90% of people in the world in one form or another, but mostly in beverages. It
is a naturally occurring substance found in plants like cocoa beans, tea
leaves, and kola nuts. Caffeine’s strongest effects are felt for about an hour
after taking it, but some effects last 4 to 6 hours. Caffeine causes increased
neuron firing in the brain, which the pituitary gland perceives as an emergency
and therefore causes the adrenal glands to release adrenaline. Caffeine also
increases dopamine levels, the neurotransmitter that is affected by drugs like
amphetamines and heroin. Obviously, it does this on a much lower level than
those drugs, but this may be the source of caffeine’s addictive quality.

1.3 The Chemical and its Sources

Caffeine is now thought to be “the most
widely used psychoactive drug in the world.” Some studies estimate that 90% or
more of this country’s population uses caffeine, whether through foods,
beverages, or prescription and over-the-counter medicines. The most common
sources of caffeine for Americans include brewed coffee, brewed tea, typical
cola drinks, milk and dark chocolate, and over-the-counter medications like
“Anacin” and “Vivarin.” Caffeine is an alkaloid, or nitrogen-containing
substance, bearing the chemical formula C8H10N4O2.It belongs to the family of
chemicals known as methylxanthines, which also includes the closely related
chemicals theophylline and theobromine.In its pure form, caffeine “occurs as
odorless, white, fleecy masses, glistening needles or powder.” As with all
methylxanthines, caffeine has low solubility and is therefore often combined with
a wide variety of compound to form complexes, such as the double salt sodium
benzoate, for purposes.


                                  Figure 1.1:
Structure of caffeine

Molecular Formula: C8H10N4O2

Molecular Weight: 194.19

Molar mass: 194.19 g/mol

1, 3, 7-Trimethylpurine-2, 6-Dione

Melting point: 455°F (235°C)

1.23 g/cm

1.4 Medically known as:trimethylxanthine

Caffeine and the other methylxanthines
are found in nature “in plants widely distributed geographically.”12 Tea, which
is prepared from the leaves of the plant Theasunensis, naturally contains all
three of the aforementioned methylxanthines and is consumed by at least half of
the entire world population.13 Cocoa and chocolate are produced “from the seeds
of Theobroma cacao”; both contain caffeine and theobromine, and both are used
the world over.14 The most obvious and important source of American caffeine
intake, coffee, is produced from the Coffeaarabica plant.15 Prior to the
deliberate insertion of additional caffeine during production, many sodas
contain a natural form of caffeine “because of their content of extracts of the
nuts of Cola acuminata.”16 While it occurs abundantly in nature from a wide
variety of sources, caffeine is also “created synthetically and by extraction


1.5 Effects of caffeine to human  

Coffee is the most frequently consumed
caffeine-containing beverage. The caffeine in coffee is a bioactive compound
with stimulatory effects on the central nervous system and a positive effect on
long-term memory. Although coffee consumption has been historically linked to
adverse health effects, new research indicates that coffee consumption may be
beneficial. Here we discuss the impact of coffee and caffeine on health and
bring attention to the changing caffeine landscape that includes new
caffeine-containing energy drinks and supplements, often targeting children and


Caffeine has numerous
physiological effects on major organ systems, including the nervous system,
cardiovascular system, digestive system, and respiratory system. Renal function
and skeletal muscles are also affected by caffeine. Numerous studies have
proven caffeine to be a stimulant to human’s central nervous system (Spiller,
1998).It is also increase heartbeat rate, dilate blood vessels and elevate
levels of free fatty acids and glucose in plasma. 1 g of caffeine leads to
insomnia, nervousness, nausea, ear ringing, flashing of light derillum and tremulosness.
In cases of overdosing and in combination with alcohol, narcotics and some
other drugs, these compounds produce a toxic effect, sometimes with lethal
outcome (Mamina and Pershin, 2002; Ben Yuhas, 2002; Wanyikaet al., 2010; James
et al., 1990; Tavallali and Sheikhaei, 2009). Caffeine facilitates the
conduction velocity in the heart and directly affects the contractility of the
heart and blood vessels. Nevertheless, caffeine may significantly reduce
cerebral blood flow by constricting of cerebral blood vessels. Caffeine
provides a diuretic effect due to elevating the blood flow and glomerular
filtration rate of the kidneys. Heartburn is an issue for some subjects’
gastrointestinal system after consuming caffeine. The effects of caffeine to
skeletal muscles are mainly the increasing occurrence of tremors

1.6 Health Benefits

In Japan, researchers have shown that caffeine increases
memory. Also, a newer study out of Johns Hopkins University showed that a 200mg
caffeine pill helped boost memory consolidation.


Caffeine may protect against
Parkinson’s disease. Research shows that those who consume coffee are at less
risk of developing Parkinson’s disease and it even reduces the risk of those
genetically more likely to develop the condition.


Caffeine may prevent skin cancer.
A new study out of Rutgers University found that caffeine prevented skin cancer
in hairless mice. Another study showed that caffeinated coffee drinkers have
less risk of developing melanoma


People who consume caffeine have a lower risk of suicide.


Caffeine may reduce fatty liver in
those with non-alcohol related fatty liver disease. This study comes out of
Duke University.


Caffeine is shown to reduce liver
fibrosis risk in patients with hepatitis C. As little as 100 mg per day is believed
to have protective benefits.


Caffeine consuming men showed
increased semen volume and significantly less sperm DNA fragmentation than
non-caffeine consuming men.Men who consume 250-375mg of caffeine per day have a
much lower risk of developing ED (erectile dysfunction). Reduced risk was even
observe among men consuming as little as 85mg of caffeine daily. This research
was conducted by The University of Texas Medical School.


Caffeine may prevent ringing in the
ears (tinnitus) in women.A study recently published in The American Journal of
Medicine followed a group of 65,085 nurses since 1991. The women who consumed
the most caffeine had the lowest incidences of tinnitus reported.


Caffeine improves reaction time and
logical reasoning during times when sleep isn’t possible or restricted.


Caffeine Reduces Kidney Stone Risk.
In a large 217,883 person study, those that consumed caffeine from any source
had less kidney stone formation than those that did not consume caffeine. The
researchers believe that this is because caffeine makes urine more dilute.



Caffeine helps those with asthma. A
study published in the U.S. National Library of Medicine concluded that
caffeine seems to open airways and help asthmatics breathe easier similarly to
theophylline a drug currently used and one that’s a close cousin to caffeine.


Reduces driver error. A
recent study conducted by the Australian Department of Defence found that
caffeine consumption improves driving performance and reduces driver error.
Caffeinated gum was used in the study on soldiers that had been sleep-deprived
for 50 hours.


Caffeine may prevent weight gain.
Research out of Germany showed that weight loss study participants who drank
2-4 cups of caffeinated coffee a day were more likely to be successful at
keeping the weight off than those who did not consume caffeine.


Caffeine reduces chronic
inflammation. Researchers from Stanford University found that caffeine blocks
the expression of a gene responsible for low-grade chronic inflammation as we
age. This inflammation


Eventually leads to high blood
pressure, hardening of the arteries, and heart disease. Caffeine seems to help
reduce this age-related inflammation in those that are regular consumers of the