A PROJECT RESEARCH ON EXTRACTION AND STUDY OF EFFECT OF HEAT ON CAFFEINE EXTRACTED FROM KOLA NUT
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.
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.
Caffeine is a bitter, white crystalline xanthine alkaloid and a psychoactivestimulant drug. Caffeine was discovered by a German chemist, Friedrich Ferdinand Runge. He coined the term kaffein, a chemical compound incoffee (the German word for which is Kaffee), which in English becamecaffeine (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.11The 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
1,3,7-trimethyl- 1H-purine- 2,6(3H,7H)-dione
1,3,7-trimethylxanthine, trimethylxanthine, methyltheobromine, 7-methyltheophylline, theine, mateine, guaranine
Odorless, white needles or powder
1.23 g/cm3, solid
227–228 °C (anhydrous); 234–235 °C (monohydrate)
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)
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.