A PROJECT RESEARCH
ON
EXTRACTION AND STUDY OF EFFECT OF HEAT ON CAFFEINE
EXTRACTED FROM KOLA NUT
BY
OKOLIE NORA CHINYERE
IC/2007/039
SUBMITTED
TO
THE
DEPARTMENT
OF
INDUSTRIAL
CHEMISTRY FACULTY OF NATURAL SCIENCE
IN
PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE
AWARD OF BACHELOR OF SCIENCES (B.Sc) DEGREE BIN
INDUSTRIAL CHEMISTRY
CARITAS UNIVERSITY, AMORJI-NIKE
ENUGU STATE
JULY 2010
CERTIFICATION PAGE
This is to certify that this project work was truly carried out by Okolie Nora
Chinyere in partial fulfillment of the requirement for the award of first
degree (B.Sc) in industrial chemistry.
------------------Okolie Nora Chinyere
----------------Date
(Reseacher)
--------------------Mr. I. Ehirim
----------------Date
Supervisor
---------------------
----------------
Prof. J. A Ibemesi
Date
Head of Department
----------------------Prof. O. Nduka
Dean
---------------Date
DEDICATION
This work is dedicated to Almighty God whose infinite love sustained me
throughout this reseach.
ACKNOWLEDGEMENT
Unending thanks goes to God Almighty who sustained me during my
reseach work.
I use this means to express my profound gratitude to my loving parents Mr.
and Mrs REGINALD OKOLIE for their effortless and toilsome work from
my childhood to this present stage to make me a valuable woman in life,
I will not fail to acknowledge my unique suprvisor who dispoed his time
willingly to see the completion of this work,
I remain ever grateful to my wonderful siblings Nancy, Esther, Mavis,
Desmond, Edith, Emmanuel, Victoria who toiled and worked so hard so as
to support me Spiritually And Financially.
I owe special gratitude to my beloved Aunty, Miss Rose-mary Njideka for
her continous spiritual and financial support thrugh out my degrre programe.
ABSTRACT
Caffeine is an odorless, slightly bitter organic compound found mostly in
beverages such as coffee or tea and in chocolate. It is the most widely used
“mind-altering drug” in the world, though it is considered safe and is mostly
unregulated. Caffeine acts as a mild stimulant on the nervous system, aiding
in alertness. Caffeine is also included in many weight loss supplements due
to its reputation of acting as an appetite suppressant and in stimulating
thermogenesis. A number of over the counter pain relievers, headache
remedies and antihistamines contain caffeine.
Product Features
Caffeine is a compound that is produced naturally in the many plants and
nuts. Although it is widely available without a prescription, caffeine
is defined as a drug because it stimulates the central nervous system,
causing increased alertness and giving most people a temporary
energy and mood boost.
Caffeine is known to stimulate
thermogenesis, one of the ways the body generates heat and energy
from digested food. Caffeine may also act as an appetite suppressant
and as a diuretic.
There are many sources of caffeine available on the market today. In
addition to being found in coffee, tea, energy waters, cocoa and
carbonated beverages, caffeine is also found in a variety of
chocolates. It is also present in a number of weight loss supplements
in the form of kola nut seeds, bissey nut, guarana, citrus aurantlum
extract and yerba mate. It is important to know what form of caffeine
is in any diet product you purchase as some do come with safety
warnings. It is also important to avoid mixing too many forms of
caffeine in one formula as this can lead to restlessness, sleeplessness
and heart irregularities.
1.0 INTRODUCTION
Kola cola is common name for a genus of about 125 species of evergreen
trees (trees that certain foliage throughout the year). It is a native to tropical
areas of the world. Kola trees are best known for their seeds or nuts which
are rich in caffeine and used in the manufacturing of carbonated soft drinks
known as kola beverages.1
Kola trees belong to the cacao family sterculiaceae. The main species grown
for their seed production are classified as kola nitida and kola
acuminate.2They are classified into these groups on the basis of the amount
of cotyledons they have: kola nitida is dicotyledonous while kola acuminate
has more than two cotyledons. Thses are two varieties of kola nitida which
are rubra and alba. 3,4
Economically, the most important kola species are those cultivated in
tropical; countries for their caffeine –rich nuts.1 Harvested by hand, the
brown nuts, which resemble chestnuts and have an aroma. Like that of
nutmeg are separated from the follicles and sun-dried, after which they are
ready for shipment. Kola forms a part of social and religious customs in
West Africa. Kola is one of the major sources of caffeine. Humans have
consumed caffeine since the Stone Age.5 Early peoples found that chewing
the seeds, bark, or leaves of certain plants had the effects of easing fatigue,
stimulating awareness, and elevating one's mood. Only much later was it
found that the effect of caffeine was increased by steeping such plants in hot
water. Global consumption of caffeine has been estimated at 120,000 tones
per year,6 making it the world's most popular psychoactive substance. This
amounts to one serving of a caffeinated beverage for every person every day.
Caffeine is a central nervous system and metabolic stimulant,7 and is used
both recreationally and medically to reduce physical fatigue and restore
mental alertness when unusual weakness or drowsiness occurs. Caffeine and
other methylxanthine derivatives are also used on newborns to treat apnea
and correct irregular heartbeats. Caffeine stimulates the central nervous
system first at the higher levels, resulting in increased alertness and
wakefulness, faster and clearer flow of thought, increased focus, and better
general body coordination, and later at the spinal cord level at higher doses.8
Once inside the body, it has a complex chemistry, and acts through several
mechanisms as described below.
Many cultures have legends that attribute the discovery of such plants to
people living many thousands of years ago.Muslims consider kola nuts to be
sacred and incorporate them in ceremonial and social occasions. When
chewed kola nuts taste bitter initially but leave a sweet, lingering aftertaste.
1.2 CHEMICAL COMPOSITION OF KOLANUTS
The analysis of the three predominant species k. acuminata and k. nitida
showed that crude protein range from 3.9-6.7%. kola contains between 1.0
and 1.2 caffeine. Kola contains a glycoside kolanine, 9% protein, 2% fat,
74% carbohydrate on fresh bases.
1.3 USES OF KOLANUTS
Use of the kola nut, like the coffee berry and tea leaf, appears to have
ancient origins.
It is chewed in many West African cultures, individually or in a social
setting, to restore vitality and ease hunger pangs.
In 1911, kola became the focus of one of the earliest documented health
scares when the US government seized 40 barrels and 20 kegs.
It is also used in the confectionary industries.
Kola is also used in masticatory and its extract is used in soft drink
manufacturing.
In addition to their use in s of drink manufacture, kola nuts are used in
traditional African folk medicine to cure stomach ulcers, diarrhea, dysentery
and other ills.
It is used to produce kola wine and also incorperated into chocolate drinks.
Kola forms a part of social and religious customs in West Africa.
Kola is a source of caffeine and also essential oils used in the confectionary
industries.
1.4 CAFFEINE
Caffeine is a bitter, white crystalline xanthine alkaloid and a
psychoactive stimulant drug. Caffeine was discovered by a German
chemist, Friedrich Ferdinand Runge. He coined the term kaffein, a
chemical compound in coffee (the German word for which is Kaffee),
which in English became caffeine (and changed to Koffein in German).9
Caffeine belongs to the family of heterocyclic compounds known as
purines.
The structure of caaffeine and other purine derivative can be shown in the
figure above .
It has the systematic name 3,7-dihydro-1,3,7-trimethyl-1H-purine-2,6dione; it is also known as 1,3,7-trimethylxanthine, and 1,3,7-trimethyl2,6-dioxopurine. Caffeine was discovered in coffee in 1820. In 1838, it
was established that theine discovered in tea in 1827 is identical to
caffeine.10
The exact composition of cola nitida have been shown to includexathine alkaloid (caffeine, theophylline, theobronine) tamin, betaine and
kolanine.11 The bitter taste is due to the presence of tamin and betaine
while the reddish stain extracted is the kolatine and kolanine content. It
occurs in the fruit and bark of a number of plants; like tea leaves, coffee,
cocoa, kola nuts, beans and mate-leave. Its molecular formula is
C8H10O2N4 with 28.85% nitrogen content.
STRUCTURE OF CAFFEINE
1.4.1 PROPERTIES OF CAFFEINE
IUPAC name
1,3,7-trimethyl- 1H-purine- 2,6(3H,7H)-dione
Other names
1,3,7-trimethylxanthine,
trimethylxanthine,
methyltheobromine, 7-methyltheophylline, theine,
mateine, guaranine
Properties
Molecular formula C8H10N4O2
Molar mass
194.19 g/mol
Exact mass
194.080376 u
Appearance
Odorless, white needles or powder
Density
1.23 g/cm3, solid
Melting point
Boiling point
227–228 °C
(anhydrous);
234–
235 °C (monohydrate)
178 °C subl.
2.17 g/100 ml
Solubility in water
18.0 g/100 ml
(25 °C)
(80 °C)
67.0 g/100 ml (100 °C)
Acidity (pKa)
−0.13–1.22[1]
Dipole moment
3.64 D (calculated)
1.4.2 CLASSIFICATION OF CAFFEINE
Caffeine can be classified as an alkaloid, a term used for substances
produced as end products of nitrogen metabolism in some plants. The
chemical formula is C 8 H
10
N 4 O 2 . Caffeine has a molar mass of 194.19
grams (6.85 ounces). It is soluble in water and in many organic solvents, and
it appears in pure form as white crystals.
1.4.3 SOLUBILITY OF CAFFEINE
Caffeine is not a highly water soluble substance and, therefore, has a
moderately slow release from
chewing gum. Caffeine is 2.1% soluble in water at room temperature, 15%
soluble in water at 80oC, and
40% soluble in boiling water.
1.5 SOURCES AND OCCURANCE OF CAFFEINE
ROASTED COFFEE BEANS, A COMMON SOURCE OF CAFFEINE
Caffeine is found in many plant species and in varying quantities
in the beans, leaves, and fruit of some plants, with high caffeine levels being
observed in seedlings that are still developing foliage, but are lacking
mechanical protection. It acts as a natural pesticide that paralyzes and kills
certain insects feeding on the plants. 12
High caffeine levels have also been found in the surrounding soil of
coffee bean seedlings. Therefore, it is understood that caffeine has a natural
function as both a natural pesticide and an inhibitor of seed germination of
other nearby coffee seedlings, thus giving it a better chance of survival.13
1.6 SOURCES OF CAFFEINE
Common sources of caffeine are coffee, tea, and to a lesser extent
chocolate derived from cocoa beans.14 Less commonly used sources of
caffeine include the yerba maté and guarana plants,[14] which are sometimes
used in the preparation of teas and energy drinks. It is most commonly
consumed by humans in infusions extracted from the bean of the coffee
plant and the leaves of the tea bush, as well as from various foods and drinks
containing products derived from the kola nut. Other sources include yerba
mate, guarana berries, and the Yaupon Holly.
Some yerba mate enthusiasts assert that mateine is a stereoisomer of
caffeine, which would make it a different substance altogether. 15 This is not
true because caffeine is an achiral molecule, and therefore has no
enantiomers; nor does it have other stereoisomers. The disparity in
experience and effects between the various natural caffeine sources could be
due to the fact that plant sources of caffeine also contain widely varying
mixtures of other xanthine alkaloids, including the cardiac stimulants
theophylline and theobromine, and other substances such as polyphenols that
can form insoluble complexes with caffeine.16
One of the world's primary sources of caffeine is the coffee bean
(which is the seed of the coffee plant), from which coffee is brewed.
Caffeine content in coffee varies widely depending on the type of coffee
bean and the method of preparation used,17 In general, dark-roast coffee has
less caffeine than lighter roasts because the roasting process reduces the
bean's caffeine content.18,19 Arabica coffee normally contains less caffeine
than the robusta variety.17 Coffee also contains trace amounts of
theophylline, but no theobromine.
Tea is another common source of caffeine. Although tea contains
more caffeine than coffee (by dry weight), a typical serving contains much
less, as tea is normally brewed much weaker. Besides strength of the brew,
growing conditions, processing techniques- and other variables also affect
caffeine content. Certain types of tea may contain somewhat more caffeine
than other teas. Tea contains small amounts of theobromine and slightly
higher levels of theophylline than coffee. Preparation and many other factors
have a significant impact on tea, and color is a very poor indicator of
caffeine content.20 Teas like the pale Japanese green tea gyokuro, for
example, contain far more caffeine than much darker teas like lapsang
souchong, which has very little.
Two of caffeine's alternative names, mateine and guaranine, are derived
from the names of these plants.[15][16]Caffeine can be prepared by extraction
from natural sources or by synthesis from uric acid.
1.7 HEALTH USES OF CAFFEINE
The precise amount of caffeine necessary to produce effects varies
from person to person depending on body size and degree of tolerance to
caffeine. The uses of caffeine can be seen both from a moderate intake view
and an over use view.
1.7.1
EFFECTS OF CAFFEINE, POSSIBLY AT A MODERATE
INTAKE
Consumption of caffeine does not eliminate the need for sleep, it only
temporarily reduces the sensation of being tired throughout the day.
Caffeine is an ergogenic, increasing a person's capability for mental or
physical labor.
Caffeine has diuretic properties when administered in sufficient doses to
subjects that do not have a tolerance for it.21 Regular users, however,
develop a strong tolerance to this effect.
Caffeine citrate has proven to be of short- and long-term benefit in treating
the breathing disorders of apnea of prematurity and bronchopulmonary
dysplasia in premature infants.22 The only short-term risk associated with
caffeine citrate treatment is a temporary reduction in weight gain during the
therapy,23 and longer term studies (18 to 21 months) have shown lasting
benefits of treatment of premature infants with caffeine.24,25
It stimulates heart muscle and relaxes certain structures that contain
smooth muscle, including the coronary arteries and the bronchi, hence it is
used in the treatment of asthma.
Caffeine relaxes the internal anal sphincter muscles and thus should be
avoided by those with fecal incontinence.26
While relatively safe for humans, caffeine is considerably more toxic to
some other animals such as dogs, horses, and parrots due to a much poorer
ability to metabolize this compound.
Caffeine also increases the effectiveness of some drugs. Caffeine makes pain
relievers 40% more effective in relieving headaches and helps the body
absorb headache medications more quickly, bringing faster relief. 27 For this
reason, many over-the-counter headache drugs include caffeine in their
formula.
It is also used with ergotamine in the treatment of migraine and cluster
headaches as well as to overcome the drowsiness caused by antihistamines.
1.7.2 OVERUSE
An acute overdose of caffeine, usually in excess of about 300 milligrams,
dependent on body weight and level of caffeine tolerance, can result in a
state
of
central
nervous
system
over-stimulation
called
caffeine
intoxication.28
The symptoms of caffeine intoxication are not unlike overdoses of other
stimulants. It may include restlessness, fidgetiness, nervousness, excitement,
euphoria, insomnia, flushing of the face, increased urination, gastrointestinal
disturbance, muscle twitching, a rambling flow of thought and speech,
irritability, irregular or rapid heart beat, and psychomotor agitation.29 In
cases of much larger overdoses, mania, depression, lapses in judgment,
disorientation, disinhibition, delusions, hallucinations, and psychosis may
occur, and rhabdomyolysis (breakdown of skeletal muscle tissue) can be
provoked.30,31
In large amounts, and especially over extended periods of time, caffeine can
lead to a condition known as caffeinism.32,33 Caffeinism usually combines
caffeine dependency with a wide range of unpleasant physical and mental
conditions including irritability, anxiety, tremulousness, muscle twitching
(hyperreflexia), insomnia, headaches, respiratory alkalosis, and heart
palpitations.34,35 Furthermore, because caffeine increases the production of
stomach acid, high usage over time can lead to peptic ulcers, erosive
esophagitis, and gastroesophageal reflux disease.
Extreme overdose can result in death.
It is not contraindicated, but highly advisable to minimize the intake of
caffeinated beverages, as drinking one cup of coffee will have the same
effect as drinking five under normal conditions.36 Death typically occurs due
to ventricular fibrillation brought about by effects of caffeine on the
cardiovascular system.
Treatment of severe caffeine intoxication is generally supportive, providing
treatment of the immediate symptoms, but if the patient has very high serum
levels of caffeine then peritoneal dialysis, hemodialysis, or hemofiltration
may be required.
1.8TOLERANCE AND WITHDRAWAL EFFECTS OF CAFFEINE
Because caffeine is primarily an antagonist of the central nervous system's
receptors for the neurotransmitter adenosine, the bodies of individuals that
regularly consume caffeine adapt to the continuous presence of the drug by
substantially increasing the number of adenosine receptors in the central
nervous system.
First, the stimulatory effects of caffeine are substantially reduced, a
phenomenon
known
as
a
tolerance
adaptation.
Second, because these adaptive responses to caffeine make individuals much
more sensitive to adenosine, a reduction in caffeine intake will effectively
increase the normal physiological effects of adenosine, resulting in
unwelcome withdrawal symptoms in tolerant users.37
Caffeine tolerance develops very quickly, especially among heavy coffee
and energy drink consumers.
Complete tolerance to sleep disruption effects of caffeine develops after
consuming 400 mg of caffeine 3 times a day for 7 days.
Complete tolerance to subjective effects of caffeine was observed to develop
after consuming 300 mg 3 times per day for 18 days, and possibly even
earlier.[89]
In another experiment, complete tolerance of caffeine was observed when
the subject consumed 750–1200 mg per day while incomplete tolerance to
caffeine has been observed in those that consume more average doses of
caffeine.38
Because adenosine, in part, serves to regulate blood pressure by causing
vasodilation, the increased effects of adenosine due to caffeine withdrawal
cause the blood vessels of the head to dilate, leading to an excess of blood in
the head and causing a headache and nausea. This means caffeine has
vasoconstriction properties.39 Reduced catecholamine activity may cause
feelings of fatigue and drowsiness. A reduction in serotonin levels when
caffeine use is stopped can cause anxiety, irritability, inability to
concentrate, and diminished motivation to initiate or to complete daily tasks;
in extreme cases it may cause mild depression. Together, these effects have
come to be known as a "crash".40
1.8.1 WITHDRAWAL SYMPTOMS: This includes headache, irritability,
an inability to concentrate, drowsiness, insomnia and pain in the stomach,
upper body, and joints41which may appear within 12 to 24 hours after
discontinuation of caffeine intake, peak at roughly 48 hours, and usually last
from one to five days, representing the time required for the number of
adenosine receptors in the brain to revert to "normal" levels, uninfluenced by
caffeine consumption. Analgesics, such as aspirin, can relieve the pain
symptoms, as can a small dose of caffeine. Most effective is a combination
of both an analgesic and a small amount of caffeine.
1.9 REASON FRO THE PRESENT RESEARCH PROJECT
There has been a lot of emphasis placed on the advantages of caffeine intake
with little or no notice on the disadvantages of the intake of caffeine
especially at high doses. This work has been carried out so as to point out
the major side effects of caffeine intake. E.g Caffeine has been removed
from the list of drugs generally regarded safe by the food and drug
administration (USA). A warning has been issued to pregnant women to
avoid or use caffeine containing foods
beverages and drugs to a lesser extent,
42
since caffeine freely crosses the
placenta. Also because of this caffeine has been suggested to cause birth
defects in human offspring similar to that seen in animal studies.
Caffeine has been suggested as a possible cause of cancer although no
studies however, have yet confirmed any of these.4 it is on record that
caffeine concentration of 200g/ml inhibits the activity of the enzyme,
deoxyribose nucleic acid (DNA) polymerase which function in carrying the
information needed to direct protein synthesis and replication. This situation
calls for reduction or complete elimination of caffeine from human diet.
Kola acuminate and kola nitida are chosen for this work because both are
indigenous to Nigeria and found throughout West African. Kola nut
constitutes rich sources of nutrients. it is noteworthy that no recent work has
been published on the extraction of caffeine from kola nuts. However there
is an estimation method by which an approximate caffeine content of the
material under investigation can be evaluated. This calculation is based on
bawely Andrew method43. The information obtained from this work can be
used in heat processing of kola grind, which may lead to the establishment
of cottage industry for kola nut processing. Extensive intake on consumption
of kola nut which is a source of caffeine excercebates benign essential
tremor in any tremor diseased victim. 44
1.10 OBJECTIVES
1. To extract and purify caffeine kolanuts .
2. To compare the caffeine extracted from different species of kolanuts.
3. To degrade the extracted caffeine thermally.
4. To study the effect of heat on it.
CHAPTER TWO
2.0 LITERATURE REVIEW
There has a been a lot of research carried out on caffeine. Some
researchers realized that moderate intake of 300 mg/day (about three cups of
coffee per day) of caffeine does not cause adverse health effects in healthy
adults, although some groups, including those with hypertension and the
elderly, may be more vulnerable. Also, regular consumers of coffee and
other caffeinated beverages may experience some undesirable, but mild,
short-lived symptoms if they stop consuming caffeine, particularly if the
cessation is abrupt. However, there is little evidence of health risks of
caffeine consumption.
In 1819, the German chemist Friedrich Ferdinand Runge isolated relatively
pure caffeine for the first time42,43 According to Runge, he did this at the
request of Johann Wolfgang von Goethe.47 Runge details his (partial)
isolation of caffeine, which he calls "Kaffebase" (i.e., a base (alkaline
substance) that exists in coffee).
In 1827, Oudry isolated "theine" from tea,48but it was later proved by
Mulder 49 and by Jobst 47 that theine was the same as caffeine.47
The structure of caffeine was elucidated near the end of the 19th century by
Hermann Emil Fischer, who was also the first to achieve its total synthesis.51
This was part of the work for which Fischer was awarded the Nobel Prize in
1902. The nitrogen atoms are all essentially planar (in sp2 orbital
hybridization), resulting in the caffeine molecule's having aromatic
character. Being readily available as a byproduct of decaffeination, caffeine
is not usually synthesized.52 If desired, it may be synthesized from
dimethylurea and malonic acid.53
In 1821, caffeine was isolated both by French chemist Pierre Jean Robiquet
and by a pair of French chemists, Pierre-Joseph Pelletier and Joseph
Bienaimé Caventou, according to Swedish chemist Jöns Jacob Berzelius in
his yearly journal.Furthermore, Berzelius stated that the French chemists had
made their discoveries independently of any knowledge of Runge's work or
of each other's work. Berzelius states ‘Caffeine is a substance in coffee’,
which simultaneously, in 1821, was discovered by Robiquet and by Pelletier
and Caventou, by whom however nothing was made known about it in print.
In 1821, Crystalizable substance was discovered in coffee by Mr. Robiquet.
During the same period, while they were searching for quinine in coffee
because coffee is considered by several doctors to be a medicine that reduces
fevers and because coffee belongs to the same family as the cinchona
[quinine] tree on their part.
Pelletier and Caventou obtained caffeine, but because their research had a
different goal and because their research had not been finished, they left
priority on this subject to Mr. Robiquet.
According to the American Psychiatric Association’s (APA), there is
currently not enough evidence to show that caffeine “dependence” is
associated with a significant clinical disorder.
However, DSM IV does provide a diagnosis of caffeine intoxication that
may occur with consumption in excess of 250 mg, in more sensitive
subpopulations
.Symptoms
may
include
excitement,
restlessness,
nervousness, insomnia, diuresis, or gastrointestinal disturbance. Other
symptoms of restlessness may occur if consumption exceeds 1,000
mg/day.
Roland Griffiths, a professor of psychiatry and neuroscience at Johns
Hopkins states ‘Caffeine is the world's most commonly used stimulant, and
that it is cheap and readily available so that people can maintain their use of
caffeine quite easily’.
The latest research demonstrates, however, that when people don't get their
usual dose they can suffer a range of withdrawal symptoms, including
headache, fatigue, and difficulty in concentrating. They may even feel like
they have the flu with nausea and muscle pain."
According to one popular Chinese legend, the Emperor of China,
accidentally discovered that when some leaves fell into boiling water, a
fragrant and restorative drink resulted54,55. The history of coffee has been
recorded as far back as the ninth century. During that time, coffee beans
were available only in their native habitat, Ethiopia.
A popular legend traces its discovery to a goatherder named Kaldi, who
apparently observed goats that became elated and sleepless at night after
grazing on coffee shrubs and, upon trying the berries that the goats had been
eating, experienced the same vitality.
In 1587, Malaye Jaziri compiled a work tracing the history and legal
controversies of coffee, entitled "Undat al safwa fi hill al-qahwa". In this
work, Jaziri recorded that one Sheikh, Jamal-al-Din al-Dhabhani, was the
first to adopt the use of coffee in 1454, and that in the 15th century the Sufis
of Yemen routinely used coffee to stay awake during prayers.
Towards the close of the 16th century, the use of coffee was recorded by a
European resident in Egypt, and about this time it came into general use in
the Near East. The appreciation of coffee as a beverage in Europe, where it
was first known as "Arabian wine," dates from the 17th century. A legend
states that, after the Ottoman Turks retreated from the walls of Vienna after
losing a battle for the city, many sacks of coffee beans were found among
their baggage. Europeans did not know what to do with all the coffee beans,
being unfamiliar with them. So Franz George Kolschitzky, a Pole who had
actually worked for the Turks, offered to take them. He subsequently taught
the Viennese how to make coffee, and the first coffee house in the Western
world was opened in Vienna, thus starting a long tradition of coffee
appreciation.56
"Despite more than a century and a half of investigation into caffeine
withdrawal, doctors and other health professionals have had no scientifically
based framework for diagnosing the syndrome," says Griffiths. In their
review, the researchers identified 57 experimental studies and nine survey
studies on caffeine withdrawal, and examined each to assess the validity of
the reported findings. The researchers identified five clusters of common
withdrawal symptoms: headache; fatigue or drowsiness; dysphoric mood
including depression and irritability; difficulty concentrating; and flu-like
symptoms of nausea, vomiting and muscle pain or stiffness.
In experimental studies, 50 percent of people experienced headache and 13
percent had clinically significant distress or functional impairment -- for
example, severe headache and other symptoms incompatible with working.
Typically, onset of symptoms occurred 12 to 24 hours after stopping
caffeine, with peak intensity between one and two days, and for duration of
two to nine days. In general, the incidence or severity of symptoms
increased with increases in daily dose, but abstinence from doses as low as
100 milligrams per day, or about one small cup of coffee, also produced
symptoms.
The research also showed that avoidance of caffeine withdrawal symptoms
motivates regular use of caffeine. For example, the satisfying feelings and
perceived benefits that many coffee users experience from their morning
coffee appear to be a simple reversal of the negative effects of caffeine
withdrawal after overnight abstinence. According to the report, caffeine is
the most widely used behaviorally active drug in the world. In North
America, 80 percent to 90 percent of adults report regular use of caffeine.
Average daily intake of caffeine among caffeine consumers in the United
States is about 280 milligrams, or about one to two mugs of coffee or three
to five bottles of soft drink, with higher intakes estimated in some European
countries. In the United States, coffee and soft drinks are the most common
sources of caffeine, with almost half of caffeine consumers ingesting
caffeine from multiple sources, including tea.
Extraction of caffeine from coffee, to produce decaffeinated coffee and
caffeine, is an important industrial process and can be performed using a
number of different solvents. Benzene, chloroform, trichloroethylene and
dichloromethane have all been used over the years but for reasons of safety,
environmental impact, cost and flavor, they have been superseded by the
following main methods:
Coffee beans are soaked in water. The water, which contains
many other compounds in addition to caffeine and contributes to the flavor
of coffee, is then passed through activated charcoal, which removes the
caffeine. The water can then be put back with the beans and evaporated dry,
leaving decaffeinated coffee with its original flavor.57 Coffee manufacturers
recover the caffeine and resell it for use in soft drinks and over-the-counter
caffeine tablets.
Supercritical carbon dioxide is an excellent nonpolar solvent for
caffeine, and is safer than the organic solvents that are otherwise used. The
extraction process is simple: CO2 is forced through the green coffee beans at
temperatures above 31.1 °C and pressures above 73 atm. Under these
conditions, CO2 is in a "supercritical" state: It has gas like properties that
allow it to penetrate deep into the beans but also liquid-like properties that
dissolve 97–99% of the caffeine. The caffeine-laden CO2 is then sprayed
with high pressure water to remove the caffeine. The caffeine can then be
isolated
by
charcoal
adsorption
(as
above)
or
by
distillation,
recrystallization, or reverse osmosis.57
More than sixty plants, including those that give us coffee, tea,
cola, and cacao, produce caffeine from the purine xanthine. Whereas
caffeine is a natural constituent in coffee, tea, chocolate, and some cola
drinks, it is added to consumer products such as soft drinks, diet pills, and
analgesics . Caffeine is said to be the most widely used drug in the world,
and more than 100 million people in the United States consume caffeine
each day. It has pharmacological uses: as a cardiac and respiratory stimulant
and as an agent that promotes kidney diuresis. A therapeutic dose of caffeine
is about the same as the amount found in an average cup of coffee, between
100 and 200 milligrams (0.0071 ounces). Decaffeinated coffee can be
prepared through extraction with a solvent (such as methylene chloride),
water extraction, or steam extraction.
Caffeine, theophylline, and aminophylline are important methylsubstituted xanthines and are widely used in clinics. In this
work, the thermodynamic characteristics of the three drugs
were studied by adiabatic calorimetry, thermogravimetric
analysis (TG) and differential scanning calorimetry (DSC). The
low temperature molar heat capacities of caffeine (in the β
crystal form), theophylline and aminophylline were measured
by heating the system from 80 to 370 K using an adiabatic
calorimeter. The results indicate that the molar heat capacity of
aminophylline is the largest while that of theophylline is the
smallest. The experimental molar heat capacities of the three
drugs were fitted to a polynomial of Cp,
m
vs the reduced
temperature (t) by means of the least fitting square method
from 80 to 370 K. Their molar heat capacities at 298.15 K were
calculated to be 226.49 J·K-1·mol-1 (for caffeine), 218.13 J·K1
·mol-1 (for theophylline), and 554.78 J·K-1·mol-1 (for
aminophylline) using the polynomial Cp, m-t. Thermodynamic
parameters (such as enthalpies and entropies relative to 298.15
K) were calculated for these drugs based on the polynomial C p,
m-t.
The results of thermal analysis show that the order of
thermal
stability
for
these
drugs
is
aminophylline＜caffeine＜theophylline.
The
temperatures,
enthalpies and entropies of the phase transitions for caffeine
and theophylline were obtained by DSC. The stabilities of the
molecular structures for caffeine and theophylline were
calculated by a first-principles calculation based on density
functional theory. The results imply that the stability of the
caffeine molecule is lower than that of theophylline and this is
in good agreement with the experimental results.
Caffeine
The TG and DTG curves of caffeine are shown in Fig. 7.
These curves show that the compounds are stable up to 175ºC and
between 175-315ºC, the total mass loss occurs in a single step.
The DTA curve of caffeine is shown in Fig. 8. The first
endothermic peak at 163ºC is due to a change of crystalline
structure in compliance with the X-ray powder patterns, as can be
seen in Fig. 9 and in agreement with the literature [10]. The
endotherm between 225-320ºC, with two peaks at 270ºC and 312ºC
are due to fusion and evaporation respectively. The evaporation of
caffeine occurs without decomposition, in compliance with the
infrared spectra of caffeine and solidified sample collected after
evaporation, as can be seen in Fig. 10.
CHAPTER THREE
3.0 MATERIALS AND METHODS
3.1 MATERIALS
1. Fresh kola nuts: Red k. acuminate and Red k. nitida
2. Tap water
3. Stove
4. Kitchen knives
5. Aluminum trays and basins
6. Stop watch
7. Thermometer
8. Manual grinder
9. Weighing balance
10.Oven
11.Measuring cylinder
12.Beakers
13. Volumetric flask
14. Small glass funnels
15. Spatula
16. Filter papers
17. Small metallic pot
18. Cornical flask
19. Round and flat bottom flask
20. Retord stand
21. Filter cloth (white cotton)
22. Stirring glass
23. Kola grind
24.Caffeine sample
25.Melting point capillary tubes
26. Smooth ceramic slab
27. Parrafin oil
28. Gallenkamp hotspot furnace
29. Small motar and pistle
30. Dessicator
31. Small crucibles
32. Non- conducting holder
33. De-ionized water
34. Activated carbon
3.1 REAGENTS
CON. SULPHURIC ACID
2M SULPHURIC ACID PREPARATION
54.37cm3 conc. H2SO4 was measured out diluted to 500cm3 using
de-ionized water. The resulting solution is 2M H2SO4
AMMONIA
2M AMMONIA PREPARATION
27.5CM3 of conc. NH3 was dissolved in de-ionized water and
made up to 500Cm3 in a volumetric flask.
LEAD ACETATE MONOHYDRATE
0.3M LEAD ACETATE PREPARATION
1.625 of lead ethanate was weighed dissolved in water and made
upto 500cm3 in a volumetric flask.
3.3 SOURCES OF THE SAMPLE USED
Kola accuminata and kola nitida species of kola nuts used in this study
was bought from
market.
3.2 PRODUCTION OF KOLA GRIND
The kola seeds were washed, weighed and steamed in a beaker
placed on a stove for about two hours The steaming temperature
ranged from 920c-1000c at atmospheric pressure. The kola seeds were
steamed to soften them.
After steaming, the system was allowed to cool to 600c before
the seeds were discharged into a basin. The seeds were washed with
tap water and re-weighed. They were manually sliced using aluminum
kitchen knives and spread on trays, which were placed in the oven.
The oven temperature were adjusted to 650c and left to dry for
24hours. The sliced dried kola were grind in a manual grinder and
stored in a dessicator.
3.3 CAFFEINE EXTRACTION FROM KOLA NUTS
Johnson’s method was used in the extraction of caffeine from
kolanut
Two 100g batches of kolanut were weighed into 2 metal pots.
750cm3 of water was added to each and boiled for about one
hour. 200cm3 of 0.3M lead acetate was added while the mixture
was made hot to precipitate acids and albumin. The hot mixture
of kola and water plus additives was filtered using a white cloth.
The solids were removed and re-boiled with 500cm3 of water
while a stand by hot water was used to wash the system.
After filtration, 2M sulphuric acid was added to the filtrate to
precipitate lead ions. The lead sulphate was filtered off. 2M of
ammonia was added to the solution until it was slightly alkaline
and cioncentrated to four times its initial strength. The
concentrate was settled for about five minutes, decanted and the
sediment was filtered with filter paper while hot. The filtration
was kept hot with steam. The latter filtrate was combined with the
decanted portion before drip extraction.
The conc. Filtrate was extracted with 3 times, 80cm3
portions of trichloromethane. The mixture was frequently
inverted in each extraction and allowed to stand for atleast
45minutes before isolation of layers. The extracts were combined.
The chloroform was distiiled to ¼ of its original volume.
The remaining chloroform was evaporated to dryness and the
crude caffeine was extracted.
FLOW DIAGRAM EXTRACTION OF CAFFEINE FROM
KOLANUTS
Kola grind
Boiling
Filtration
Concentration
Cooling
Extraction
Organic extract
Distillation
Drying
Crude caffeine
Purification
Purified caffeine
3.6 PURIFICATION OF CAFFEINE
The crude caffeine was dissolved in hot water, Activated
charcoal was added to absorb the gas and the colouring matter and
filtered. The filtrate was cooled to room temperature followed by drip
extraction. The solvent was evaporated on a hot plate. The purified
dry caffeine was recovered and stord in the dessicator.
3.7MELTING POINT DETERMINATION
A small quantity of caffeine sample was finely introduced into the
capillary tube to a height of 0.5cm3 beaker containing paraffin oil
and heated. The temperature at which the caffeine melted was
noted. The procedure was repited to ensure homogeneity of result.
3.8 THERMAL DEGRADATION OF CAFFEINE
100g of the cadffeine sample was accurately weighed out using
meter p balance. The caffeine was powdered in the motar with the
pistle. The temperature of the furnace was set at 2400c. The sample
was introduced and heated at this temperature for about 10 minutes
and then reweighed. Other samples were introduced and heated for
10mins, 15mins and other times.
The above processes were repeated at temperatures of 2600c,
2800c, 3000c. The tables are shown below.
CHAPTER FIVE
Advantages.
Caffeine is a natural product which is generally considered safe.
Disadvantages
Too much caffeine can cause side effects.
Caffeine has a number of forms, so its presence can be hard to detect.
Conclusion
Many weight loss supplements include caffeine due to its ability to act as a
thermogenic agent and because of its reputation as an appetite
suppressant. It is hard to say how much caffeine needs to be
consumed to achieve a weight loss benefit. It should be noted that
some products load their formulas with a number of stimulants in
different forms so the consumer should check labels carefully.
Caffeine may not be the right ingredient for those who have a history
of nervousness, insomnia or general irritability.
Anyone on
medication should check with their physician for possible interactions
prior to use.
Keywords： Low temperature heat capacity
Aminophylline Thermal analysis
Caffeine
Theophylline
Received: 2010-03-26 Accepted: 2010-04-16 Online: 2010-06-30
Corresponding Authors: SUN Li-Xian Email: lxsun@dicp.ac.cn
Introduction
Several investigations have been carried out on the application of
thermoanalytical techniques for the study of drug substances,
excipients and drug substances in dosage forms. Montagut
and co-work [1] investigated dipyrone by employing DTA
and TG, and examined the possibility of applying TG in
quantitative studies. Wendlandt and Collins [2] used DTA
and TG as aids in the characterization and identification of
commercial
non-preescription
analgesics.
Other
investigations of the use of thermoanalytical techniques for
the study of drug substances and for applications in routine
pharmaceutical analysis and in the pharmaceutical industry
have also been described [3-20].
In this paper derivative compounds of purine were investigated by
using thermoanalytical techniques (TG, DTA), X-ray
diffractometry and infrared spectroscopy.
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a
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coffee).
44 ^ In 1821, caffeine was isolated both by French chemist Pierre Jean
Robiquet and by a pair of French chemists, Pierre-Joseph Pelletier and
Joseph Bienaimé Caventou, according to Swedish chemist Jöns Jacob
Berzelius in his yearly journal, Jahres-Bericht über die Fortschritte der
physischen Wissenschaften von Jacob Berzelius [Annual report on the
progress of the physical sciences by Jacob Berzelius] (Dr. F. Wöhler,
trans.), vol. 4, page 180, 1825. Furthermore, Berzelius stated that the
French chemists had made their discoveries independently of any
knowledge of Runge's work or of each other's work. Berzelius states on
page 180: "Cafein is eine Materie im Kaffee, die zu gleicher Zeit, 1821,
von Robiquet und [von] Pelletier und Caventou entdekt wurde, von
denen aber keine etwas darüber im Drucke bekannt machte." (Caffeine is
a substance in coffee, which simultaneously, in 1821, was discovered by
Robiquet and by Pelletier and Caventou, by whom however nothing was
made
known
about
it
in
print.)
In Pelletier's article on caffeine -- "Cafeine", pages 35-36 in Dictionnaire
de Médecine (Paris, France: Béchet Jeune, April 1822), vol. 4 -- Pelletier
himself corroborates Berzelius's account: "Cafeine, s. f. Principe
cristallisable décovert dans le café en 1821 par M. Robiquet. A la mème
époque, cherchant la quinine dans le café, parce que le café, considéré par
plusieurs médecins come fébrifuge, est d'ailleurs de la mème famille que
le quinquina, MM. Pelletier et Caventou obtenaient de leur côté la
cafeine; mais leur recherches n'ayant qu'un but indirect, et n'ayant pas été
terminées, laissent à M. Robiquet la priorité sur cet objet. Nous ignorons
pourquoi M. Robiquet n'a pas publié l'analyse du café qu'il a lue à la
société de pharmacie. Sa publication nous aurait permis de mieux faire
connaître la cafeine, et de donner des idées exactes sur la composition du
café...." (Caffeine, noun (feminine). Crystalizable substance discovered
in coffee in 1821 by Mr. Robiquet. During the same period -- while they
were searching for quinine in coffee because coffee is considered by
several doctors to be a medicine that reduces fevers and because coffee
belongs to the same family as the cinchona [quinine] tree -- on their part,
Mssrs. Pelletier and Caventou obtained caffeine; but because their
research had a different goal and because their research had not been
finished, they left priority on this subject to Mr. Robiquet. We will ignore
why Mr. Robiquet has not published the analysis of coffee which he read
to the Pharmacy Society. Its publication would allow us to make caffeine
better known and give us accurate ideas of coffee's composition .... )
In Robiquet's article on coffee -- "Cafe," pages 50-61 in Dictionnaire
Technologique, ou Nouveau Dictionnaire Universel des Arts et Métiers,
... (Paris, France: Thomine et Fortic, 1823), vol. 4 -- Robiquet gives an
account of his research on coffee on pages 54-56, detailing the extraction
of
caffeine
and
its
properties
on
pages
55-56.
Pelletier's elemental analysis of caffeine appears on pages 182-183 of the
article: Dumas and Pelletier (1823) "Recherches sur la composition
élémentaire et sur quelques propriéte's caractéristiques des bases
salifiables organiques" (Researchs into the elemental composition and
some characteristic properties of organic bases), Annales de Chimie et de
Physique,
vol.
24,
pages
163-191.
Berzelius later acknowledged Runge's priority in the extraction of
caffeine:
Jahres-Bericht
über
die
Fortschritte
der
physischen
Wissenschaften von Jacob Berzelius, vol 7, page 270, 1828. Berzelius
stated: "Es darf indessen hierbei nicht unerwähnt bleiben, dass Runge (in
seinen phytochemischen Entdeckungen 1820, p.146-7.) dieselben
Methode angegeben, und das Caffein unter dem Namen Caffeebase ein
Jahr eher beschrieben hat, als Robiquet, dem die Entdeckung dieser
Substanz gewöhnlich zugeschrieben wird, in einer Zussamenkunft der
Societé de Pharmacie in Paris die erste mündliche Mittheilung darüber
gab." (However, at this point, it should not remain unmentioned that
Runge (in his Phytochemical Discoveries, 1820, pages 146-147)
specified the same method and described caffeine by the name
Caffeebase a year earlier than Robiquet, to whom the discovery of this
substance is usually attributed, having made the first oral announcement
about it at a meeting of the Pharmacy Society in Paris.)
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pages 49-50.
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caffeine and theine), Journal für practische Chemie, vol. 15, pages 280ff.
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to caffeine), Liebig's Annalen der Chemie und Pharmacie, vol. 25, pages
63-66.
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