Research Article

Corresponding Author:Anil Pawar, Assistant Professor, Department of Zoology, D.A.V. College for Girls, Yamunanagar (Haryana); Mobile:919467604205; Email: sumanil27@yahoo.co.in

Received: 16.6.2014 Revised: 11.7.2014 Accepted: 29.7.2014

Int J Cur Res Rev | Vol 7 • Issue 9 • May 2015 16

CAFFEINE EXTRACTION AND CHARACTERIZATION

Pradeep S.1, G. N. Rameshaiah2, Hadagali Ashoka1, Chandraprasad M.1 1Department of Biotechnology, 2Department of Chemical Engineering BMS College of Engineering, Bull Temple Road, Bangalore- 560019, Karnataka, India.

ABSTRACTCaffeineextracted and characterised from tea (black) leaves and coffee beans. Isolation was done by liquid-liquid extraction us-ing di-chloromethane as an extracting agent. This extraction was done in four steps: steeping, evaporation, liquid-liquid extrac-tion and recrystallization. The recrystallization was done using anhydrous sodium sulphate.The technique used for purity analy-sis and characterisation were: High performance liquid chromatography, Differential scanning calorimeter, Fourier transform infrared spectroscopyand Melting point. First, the analysis was done using melting point analysis. The melting point of caffeine extracted from coffee beans and tea leaves was found to be 238°C. The absorption bands were compared with that available in literature and were found to be similar. Further, the purity check was done using High performance liquid chromatography method.Effective characterization of caffeine was achieved by determining Infrared spectrum, and employing a melting point ap-paratus and differential scanning calorimeter. The purity showed that the results that the extracted coffee was 90% pure. Further improvements in extraction efficiency will increase the yield and minimize wastage.Key Words: Caffeine, Methyl xanthine, Theophylline, Differential scanning calorimeter, Fourier transform infrared spectroscopy, High performance liquid chromatography

Corresponding Author:Pradeep S., Department of Biotechnology BMS College of Engineering, Bull Temple Road, Bangalore- 560019, Karnataka, IndiaE-mail: padees@gmail.com

Received: 13.02.2015 Revised: 11.03.2015 Accepted: 10.04.2015

INTRODUCTION

Caffeine is a psychoactive CNS stimulant drug discovered by German chemist Friedrich Ferdinand Runge in 1819. He coined the term ‘Kaffein’ which became Caffeine5.Caf-feine is a methyl xanthine along with theophylline and theobromine.It is a natural pesticide.Caffeine does not counteract the effects of alcohol. Caffeine is a xanthine alkaloid compound that acts as a stimulant in humans. It is a central nervous stimulant, having the effect of tem-porarily warding off drowsiness and restoring alertness.2 Every time we drink tea, coffee, cocoa, chocolate or cola we are giving our body a “hit” of caffeine. Along with nicotine and alcohol, caffeine is one of the three most widely used mood – affecting drugs in the world5.

OBJECTIVES

1. �To extract caffeine from tea leaves and coffee beans by liquid-liquid extraction method.

2. �To characterize the obtained caffeine by melting point, Infrared spectroscopy and Differential scanning calorimetermethod.

3. �To develop an easily adaptable method for the qualita-tive or purity analysis of caffeine

PHYSICAL AND CHEMICAL PROPERTIES

Caffeine is sparingly soluble in most polar solvents but is highly soluble in less polar solvents. The melting point is 234°C-239°C and the chemical formula is C8H10N4O2 .It is an intensely bitter, white powder in its pure state. Caf-feine is an alkaloid of the methylxanthine family, which also includes the similar compounds theophylline and theobromine2.The structure of caffeine is

ADMET OF CAFFEINE

Absorption & DistributionCaffeine is absorbed orally with a max blood peak af-ter 120 mins spreading quickly in all tissues.Caffeine is

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classified as a stimulant because it increases the activ-ity of cardiovascular, digestive and sympathetic nervous system, and produces the sense of alertness in the brain.It can have a lethal effect ( acute intoxication) when in-gested at amounts of 1-5 g, with plasma concentrations higher than 80mg/ml and the first intoxication signs ap-pear at about 250mg4.

Metabolism and EliminationHepatic metabolism becomes longer and more difficult in presence of alcohol and medical drugs while cigarette smoke accelerates its hepatic metabolism.Only 10% is eliminated through the kidney as unmodified caffeine4.

Caffeine intoxicationThe symptoms include restlessness, nervousness, and ex-citement, insomnia, flushing of the face, increased urina-tion, gastro-intestinal disturbance, muscle twitching, and psychomotor agitation.The treatment is based on serum levels of caffeine which may be followed by peritoneal dialysis, hemodialysis, or hemo filtration. Caffeine stimu-lates acid production in the stomach so it is better not to drink coffee in case of gastric ulcer4

Table 1: Caffeine content of selected common food and drug products.

Sl. No. Product Serving size Caffeine/serving in mg

1. Caffeine tablet

One tablet 200

2. Chocolate One bar(43g) 31

3. Soft drinks 350ml 34

EXTRACTION OF CAFFEINE

Steeping procedure is used.The solvent used is dichlo-romethane.Purification methods like distillation and recrystallization are also followed.The success of extrac-tion involving a natural product is often expressed as percentage recovery.

% recovery = Grams of caffeine recovered

Grams of tea leaves

The percentage recovery is called the purified percent recoveryor crude percent recovery. The extraction with the highest percent recovery is considered the most suc-cessful extraction5.

MATERIALS REQUIRED

5g of tea leaves, 10g coffee beans, 4g of calcium car-bonate, 2g sodium carbonate, 25ml methylene chlo-

ride, anhydrous sodium sulphate, Whatmann no.1 filter paper,15ml of dichloromethane,50ml and 500ml of Er-lenmeyer flask, separating funnels, MilliQwater,etc.

CHARACTERIZATION OF CAFFEINE

Based on various physical methods.

1. Determination of melting point

2. Infrared spectroscopy

3. Degradation by Differential scanning calorimeter

4. Purity check by High performance liquid chromatog-raphy

RESULTS

Extraction of caffeine from tea and coffee was achieved by using chloroform as an extracting solvent.

Table 2: Isolation and purification of caffeine from tea and coffee

Sl.no Sample Amt of sample(g)

Amt of caffeine after solvent extraction(g)

1. Tea 5 0.167

2. Coffee 5 0.252

Table 3: Characteristic Infrared- Absorption bands of sample and standardSl.no Bonds Standard Tea Coffee

1. C-H 2955.23 2955.50 2956.25

2. C=C 1550.03 1550.57 1550.25

3. C=O 1701.30 1701.96 1701.41

4. C-N 1239.95 1240.18 1240.49

5. C=N 1660.77 1661.25 1661.89

Table 4: Characteristics of purified caffeine isolated from tea and coffeeSl. no

Sample Melting point Average

1. Standard 238.25 238.15 238.25 238.2

2. Tea 237.45 237.5 237.85 237.6

3. coffee 237.85 237.95 238.55 238.11

Table 5: Differential scanning calorimeter

Sl.no Sample Degradation point

1. Standard 237.41

2. Tea 237.69

3. Coffee 237.45

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Table 6: Caffeine determination in green tea, black tea and coffee. (byHigh performance liquid chroma-tography )Sl. no

Sample RT(mins) Area Height Area%

1. Standard 12.13 8541.18 548.12 99.96

2. Tea 12.14 7348.59 471.26 89.75

3. Coffee 12.15 7406.75 483.39 89.62

Figure 1: Melting point reading.

Figure 2: Fourier transform infrared spectroscopy spectrum of caffeine sample

Figure 3: Differential scanning calorimeter reading of caffeine samples

Figure 4: Peak areas of caffeine sample obtained through newly adapted High performance liquid chromatography meth-od.

DISCUSSION

It was observed that the extraction efficiency of caffeine from various sources by using chloroform was much higher than other solvents. Table 2 shows the extraction efficiency of crude caffeine from tea and coffee leaves. The amount of caffeine obtained from L- L extraction af-ter further recrystallization was found to be 3.37% from tea and 5.04% from coffee.We observed that coffee con-tained a high percentage of crude caffeine as compared to tea. To purify the crude caffeine, similar procedures were utilized.

However, the caffeine content of various sources varies with soil conditions and climate. Table 3-6 shows the characteristics of caffeine in various parameters for both sample and standard respectively. Also 2-5 shows the re-sult of caffeine samples being measured respectively.

The pure white crystalline caffeine isolated from sources was found to melt at 238oC. The Infrared-spectrum of isolated caffeine showed similar absorption bands simi-lar to that given in literature. The Infrared-spectrum in-dicates the absolute purity of the purified caffeine.

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We have developed a High performance liquid chro-matography method for the determination of caffeine, which was carried by High Performance Liquid Chroma-tography instead of using UV- Visible spectrophotometer.

We chose High performance liquid chromatography method for the determination of caffeine, because High performance liquid chromatography is the most widely used qualitative and quantitative determination and separation method. This method is popular because it is non-destructive and unlike gas chromatography may be applied to thermally liable compounds. Moreover it is also a very sensitive technique as it incorporates a wide range of detection methods. With the use of post column derivatization methods to improve selectivity and detec-tion limits, High performance liquid chromatography can easily be extended to trace determination of compounds that do not usually provide adequate detector response.

The wide applicability of High performance liquid chro-matography as a separation method makes it a valuable separation tool in many scientific fields.

By using this method, we determined the retention time and the relative peak area of extracted purified caffeine. The retention time of the purified caffeine and that of the standard caffeine were almost similar, which confirmed the identity of caffeine. The amount of extracted purified caffeine for different samples was determined by study-ing the relative peak area on the calibration curve.

CONCLUSION

A method has been developed for the extraction, puri-fication of caffeine from tea and coffee. Caffeine from tea and coffee was extracted by liquid- liquid extraction followed by recrystallization. The purified caffeine was then analysed by High performance liquid chromatogra-phy. Effective characterization of caffeine was achieved by determining IR spectrum, and employing a melting point apparatus and differential scanning calorimeter.

The serious concern about potential use of caffeine for pathogenic effects has made it one of the most broadly studied drugs. It provides clinicians with the information they require in order to understand, diagnose and treat the effects of caffeine consumption in their patients.

ACKNOWLEDGEMENT

Authors acknowledge the immense help received from the scholars whose articles are cited and included in ref-erences of this manuscript. Authors are also grateful to authors, editors and publishers of all those articles, jour-nals and books from where the literature for this article has been reviewed and discussed.

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