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-2,6-dione; it is also known as 1,3,7-trimethylxanthine, and 1,3,7-trimethyl-2,6-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 include- xathine 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
227–228 °C (anhydrous); 234–235 °C (monohydrate)

Boiling point
178 °C subl.

Solubility in water
2.17 g/100 ml (25 °C) 18.0 g/100 ml (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.

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.