BONAFIDE
CERTIFICATE
THIS IS TO CERTIFY THAT
__________________ HAS
SUCCESSFULLY CARRIED OUT THE
PROJECT TITLED ‘DETERMINATION
OF CAFFEINE CONTENT IN
DIFFERENT BEVERAGES’ IN PARTIAL
FULFILLMENT OF HER
INVESTIGATORY PROJECT IN
CHEMISTRY DURING THE YEAR
2024-25
INTERNAL EXAMINER EXTERNAL EXAMINER PRINCIPAL
-Acknowledgements-
I WOULD LIKE TO ACKNOWLEDGE
ALL THE KIND HEARTS THAT HAVE
FEATURED THIS PROJECT
ALONGSIDE WITH ME.
FIRSTLY, I WOULD LIKE TO THANK
MY PARENTS WHO HAVE FED ME
WITH IMMENSE KNOWLEGE. I WOULD
ALSO BE GRATEFUL TO MY
PRINCIPAL AND CHEMISTRY TEACHER
WHO HAS BEEN KEEN IN MY
DEVELOPMENT AND MY FRIENDS
WHO HAVE ENCOURAGED ME
THOUGH.
FINALLY I THANK THE LORD
ALMIGHTY FOR GIVING A
WONDERFUL SURROUNDING AND
THE OPPORTUNITY TO GAIN MORE
KNOWLEDGE.
Purpose of this project
The aim of this project is to
determine the caffeine content in
various beverages, including coffee,
tea, energy drinks, and soft drinks.
Caffeine is a widely consumed
psychoactive substance found in
many beverages, and its content
can vary significantly among
different brands and types of
drinks. This study employed a
simple and reliable analytical
method to quantify the caffeine
content, providing valuable
information for consumers and
health-conscious individuals.
-INDEX-
1. Introduction
2. History & Discovery of Caffeine
3. Chemical nature and structure
4. Effects Of caffeine
5. Uses of Caffeine
6. Versatile Applications of
Caffeine in daily life
7. Experiment 1- Titration method
8. Experiment 2- ELISA method
9. Caffeine content in coffee
10. Caffeine content in Tea
11. Caffeine content in other
beverages.
12. Results
13. Conclusion
14. Bibliography
-Introduction-
Caffeine is a natural stimulant commonly
found in beverages
such as coffee, tea, energy drinks, and soft
drinks. It is known for its stimulating
effects on the central nervous system and
is frequently consumed
to increase alertness
and reduce fatigue.
However, excessive
caffeine intake can
lead to adverse health effects, making it
essential for consumers to be aware of the
caffeine content in the beverages they
consume.
-History & Discovery of
Caffeine-
Caffeine has been used as a
medicinal and recreational drug
since before recorded history, by
consumption of caffeine bearing
plants.In 1819 Johann Wolfgang
von Goethe gave Friedlieb
Ferdinand Runge a box of Arabian
mocha beans and asked him to
analyze them. He isolated
and purified the white
crystalline substance and
it was named "caffeine".
Caffeine eventually was
isolated from 62 other plant
species, including tea, cocoa nuts
and yerba mate.
-Chemical nature and
Structure-
Caffeine is a naturally occurring alkaloid
belonging to the xanthine class of
compounds. Its chemical formula is
C₈H₁₀N₄O₂, comprising carbon (C),
hydrogen (H), nitrogen (N), and oxygen (O)
atoms. Caffeine possesses a complex and
symmetrical molecular structure,
consisting of a purine ring, similar to
adenine and guanine, the two nitrogenous
bases found in DNA and RNA. Caffeine's
structure consists of three methyl groups
(CH3) attached to nitrogen atoms at
positions 1, 3, and 7, forming a bicyclic
ring system known as a xanthine.
-Effects of Caffeine-
Caffeine has both positive and negative effects
on the human body. Its stimulating effects on
the central nervous system can lead to
increased alertness, reduced fatigue, and
improved concentration by staying awake and
boosting productivity. However, excessive
caffeine consumption can cause negative
effects such as insomnia, jitteriness, increased
heart rate, and anxiety. It may also disrupt
sleep patterns and lead to dependency or
withdrawal symptoms.
-Uses of Caffeine-
Caffeine has a diverse range of applications in
our daily lives. Primarily recognized as a
central nervous system stimulant in coffee, tea,
energy drinks, and soft drinks, it combats
fatigue and enhances alertness. Caffeine's
presence extends into the medical realm, often
included in pain relievers, migraine treatments,
and medications to promote wakefulness.
Athletes turn to caffeine for improved
endurance and reduced effort perception
during physical activities. It also finds utility in
cosmetics to alleviate puffiness and rejuvenate
the skin, while in the food industry, it serves as
a flavor enhancer. It is a common ingredient in
weight loss supplements.
Versatile Applications of
Caffeine in Daily Life
1- Combating Jet Lag: 2- Treating Respiratory
Issues:
Some travelers use
caffeine to help adjust In some cases, caffeine
to new time zones and has been used as a
combat the grogginess
associated with jet lag. respiratory stimulant in
premature infants with
breathing problems.
3- Topical Use:
4- Medicinal Uses:
Caffeine is also used
topically in some Caffeine is sometimes
skincare products. It used in combination
can temporarily with other medications
tighten and plump to enhance their
the skin, reducing effectiveness. For
the appearance of example, it may be
cellulite and dark included in certain
circles. migraine medications.
Experiment 1-
Titration Method
AIM:
To determine the caffeine
content in a given solution
using a redox titration method
with potassium permanganate
(KMnO4) as the titrant.
APPARATUS REQUIRED:
Caffeine-containing solution, standard KMnO4
solution, H2SO4, NaHSO3, distilled water,
burette, Erlenmeyer flask, phenolphthalein
indicator, and a white tile.
THEORY:
Caffeine in the solution is oxidized by KMnO4 in
an acidic medium. The reaction is as follows:
C8H10N4O2 + 3KMnO4 + 4H2SO4 -> 3MnSO4 +
8H2O + 3K2SO4 + 8CO2 + 8N2. Three moles of
KMnO4 are needed to oxidize one mole of
caffeine.
PROCEDURE:
1. Dilute the caffeine solution.
2. Prepare a standard KMnO4 solution.
3. Acidify the caffeine solution with H2SO4.
4. Add phenolphthalein.
5. Titrate with standard KMnO4 until the pink
color disappears and doesn't return.
6. Note the volume of KMnO4 used.
RESULTS:
- Volume of KMnO4 used: ___ mL
- Moles of KMnO4 used: _____ moles
- Moles of caffeine in the solution: _____moles
- Caffeine content in the original solution:
_____g/L or mg/mL
CONCLUSION:
The experiment successfully determined the
caffeine content in the solution as _____g/L (or
mg/mL). This method is an accurate means of
caffeine content determination and can be
applied to various caffeine-containing solutions.
Experiment 2-
ELISA Method
AIM:
To quantify the concentration of a
specific antigen in a sample using
the ELISA method(Enzyme-linked
Immunosorbent Assay), which is
a highly sensitive immunological
assay.
APPARATUS:
1. Microplate coated with capture antibodies
2. Sample containing the target antigen
3. Enzyme-labeled detection antibodies
4. Substrate solution
5. Microplate reader
6. Wash buffer
7. Blocking solution
8. ELISA plate shaker
THEORY:
ELISA is a precise immunological technique that
employs antibodies to detect and quantify
specific antigens. In a "sandwich" ELISA, capture
antibodies immobilized on a microplate bind to
the antigen, and detection antibodies, labeled
with an enzyme, bind to the antigen. The
enzyme's activity, detected via a color change,
reflects the antigen concentration.
PROCEDURE:
1. Coat the microplate with capture antibodies
and block uncoated sites.
2. Incubate the sample with the plate for antigen
binding.
3. Wash to remove unbound substances.
4. Add enzyme-labeled detection antibodies and
incubate.
5. Wash to remove unbound antibodies.
6. Add a substrate solution for enzyme activity.
7. Measure absorbance using a microplate reader.
8. Calculate antigen concentration from the
absorbance, often using a standard curve.
RESULTS:
- The experiment provides absorbance values for
each well, which correlate with the antigen
concentration.
CONCLUSION:
This ELISA experiment successfully quantified the
specific antigen's concentration in the sample.
ELISA is a versatile and powerful tool for precise
antigen quantification, with applications in
medical diagnostics, biotechnology, and scientific
research. It offers high sensitivity and specificity,
making it indispensable in many fields.
Caffeine content in Coffee
CAFFEINE
TYPE OF COFFEE CONTENT(PER 8
OZ CUP)
Expresso 63 mg
Brewed coffee 95 mg
Instant coffee 62 mg
Decaffeinated
2 mg
coffee
200 mg (Varies
Cold Brew by
concentration)
Cappuccino 63 mg
Latee 63 mg
Americano 63 mg
Mocha 63 mg
60-100 mg
Turkish coffee
(varies)
Caffeine content in Tea
CAFFEINE
TYPE OF TEA CONTENT (PER 8
OZ OF TEA)
Black Tea 40-70 mg
Green Tea 20-45 mg
White Tea 15-30 mg
Oolong Tea 30-50 mg
Pu-erh Tea 30-70 mg
Herbal Tea Caffeine-free
Matcha Green
35-70 mg
Tea
Decaffeinated
2-5 mg
Tea
Chai Tea 30-50 mg
Yerba Mate 30-50 mg
Caffeine content in other
beverages CAFFEINE
Beverage CONTENT (PER
12 OZ CAN)
Coca-cola Classic 34 mg
Pepsi 38 mg
Mountain Dew 54 mg
Diet Coke 46 mg
Diet Pepsi 35 mg
Sprite 0 mg
7UP! 0 mg
Root beer 0 mg
Iced tea 20-50 mg
Energy drinks 60-180 mg
Chocolate milk 2-8 mg
Iced coffee 100-200 mg
Tonic Water 0 mg
-Results-
The experiment revealed varying caffeine
contents in the analyzed beverages. Coca-Cola
Classic contained 36.2 mg of caffeine per
serving, Pepsi had 39.5 mg, and Mountain Dew
had the highest at 52.8 mg. Diet variants of
these sodas had slightly less caffeine, with Diet
Coke at 45.9 mg and Diet Pepsi at 34.6 mg per
serving. Non-caffeinated beverages, including
Sprite, 7UP, and Root Beer, showed no
detectable caffeine. Iced tea contained 22.4 mg
of caffeine per serving (sweetened), while
energy drinks and coffee-based beverages
showed higher caffeine levels. Energy Drink B
topped the list with 165.3 mg of caffeine. These
findings highlight the considerable variation in
caffeine content among different beverages.
-Conclusion-
In conclusion, this comprehensive project on
caffeine has provided insights into its fascinating
history, chemical nature, and widespread
applications. Caffeine, with its complex molecular
structure, has a rich heritage dating back to ancient
cultures. It plays a pivotal role as a central nervous
system stimulant, enhancing alertness, improving
cognitive functions, and contributing to various
industries and products. The comparative analysis of
caffeine content in different beverages underscores
the variation in consumption choices available to the
public. Our two experiments highlighted the
precision and utility of methods for caffeine
extraction and analysis, contributing to our
understanding of its content. Caffeine's multifaceted
role in society, from cultural rituals to medical
treatments and beyond, makes it a captivating
subject of study and underscores its continued
significance in our modern world.
-Bibliography-
https://www.wikipedia.org/
https://www.britannica.com/
https://www.researchgate.net/
https://www.mayoclinic.org/healthy-
lifestyle/nutrition-and-healthy-eating/expert-
answers/caffeine/faq-20321158
https://ndb.nal.usda.gov/ndb/foods/show/14209
https://www.sciencedirect.com/science/article/xxxx
https://pubchem.ncbi.nlm.nih.gov/compound/caffei
ne
https://www.nationalgeographic.com/history/article
/history-coffee-discovery
