Instituto Brillamont
Science fair 2014-2015
Written report
Which decaffeinated process is better for decaffeinating coffee?
Mrs. Pilar Hernández
Mr. Carlos Andrés Colunga
Team members:
Carlos Alvarez #2
Mauricio Cavazos #9
Alejandro chinchilla #10
Eduardo Villarreal #27
February 4, 2015
Background research:
Coffee has become an important part of our lives in the industrial system of the
20th & 21st century. While both helping the average working man in an office or any
other workplace and satisfying the developing need from caffeine by a new
generation in need of energy and motivation. Caffeine both in and outside of the
workplace has become an essential part in our daily lives, and also in contrast the
need for non- caffeinated beverages that satisfy the need for a hot beverage on an
early cold morning.
Non caffeinated beverages also take part in various processes that help keep the
delicious taste of coffee while eliminating the energy inducing properties of caffeine.
This processes are use on green coffee bean and we would like to know how they
work and what those producers are.
Dichloromethane (DCM, or methylene chloride) is an organic compound with the
formula CH2Cl2. This colorless, volatile liquid with a moderately sweet aroma is
widely used as a solvent. Although it is not miscible with water, it is miscible with
many organic solvents. One of the most well-known applications of
dichloromethane is in the decaffeinating coffee.
The formula of the methylene chloride is CH2Cl2
Ethyl acetate is the organic compound with the formula CH3-COO-CH2-CH3.
This colorless liquid has a characteristic sweet smell (similar to pear drops) and is
used in glues, nail polish removers, decaffeinating tea and coffee, and cigarettes.
Ethyl acetate is the ester of ethanol and acetic; it is manufactured on a large scale
for use as a solvent. The combined annual production in 1985 of Japan, North
America, and Europe was about 400,000 tons. In 2004, an estimated 1.3M tons
were produced worldwide.
The formula of ethyl acetate is C4H8O2
Decaffeination (decaf) is the removal of caffeine from coffee
beans, cocoa, tea leaves and other caffeine-containing materials. While soft
drinks which do not use caffeine as an ingredient are sometimes described as
"decaffeinated", they are better termed "uncaffeinated" because decaffeinated
implies that there was caffeine present at one point in time. Decaffeinated drinks
contain typically 1–2% of the original caffeine content, and sometimes as much as
20%.
In the case of coffee, various methods can be used. The process is usually
performed on unroasted (green) beans, and starts with steaming of the beans.
They are then rinsed with a solvent that extracts the caffeine while leaving other
constituents largely unaffected. The process is repeated from 8 to 12 times until
the caffeine content meets the required standard (97% of caffeine removed
according to the international standard, or 99.9% caffeine-free by mass as per
the EU standard). Coffee contains over 400 components important to the taste and
aroma of the drink, so it is difficult to remove the caffeine without affecting other
components.
Water is capable of dissolving a variety of different substances, which is why it
is such a good solvent. In fact, water is called the "universal solvent" because it
dissolves more substances than any other liquid. This is important to every living
thing on earth. It means that wherever water goes, either through the air, the
ground, or through our bodies, it takes along valuable chemicals, minerals, and
nutrients.
It is water's chemical composition and physical attributes that make it such an
excellent solvent. Water molecules have a polar arrangement of oxygen and
hydrogen atoms—one side (hydrogen) has a positive electrical charge and the
other side (oxygen) had a negative charge. This allows the water molecule to
become attracted to many other different types of molecules. Water can become
so heavily attracted to a different compound, like salt (NaCl), that it can disrupt the
attractive forces that hold the sodium and chloride in the salt compound together
and, thus, dissolves it.
The formula of water is H2O
The water process is not really use by humans because at the moment you put
water in the coffee beans you will not only extract the caffeine also other
substances that give that delicious flavor to the coffee that’s why humans do not
use so often that method, and the purity of the caffeine is not the same if you use
another method.
Purpose:
Coffee has become one of the most drinked beverages in the whole world and
also one of the first drinked things in the morning, coffee is the one that helps you to
wake you up in the morning to have more energy for work. But some people do not
need the caffeine in their coffee they only want the taste of the coffee.
That’s why we made a project to show how many coffee is inside the regular
coffee and the methods we have to decaff coffee.
Hypothesis:
If ethyl acetate has a higher kPa than methylene chloride and water, then we
think that the acidity will have a larger effect on the raw coffee beans and normal
coffee, and therefore, will extract more caffeine from them.
Materials:
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Methylene chloride
Ethyl acetate
Water
Green coffee beans
Nescafe clasico
Measuring cup
Glass bowl
Spoon
Procedure:
Methylene chloride
1.
2.
3.
4.
5.
6.
7.
8.
Take a cup of water and put it on the glass bowl
Take 2 table spoons of coffee and put it on the bowl of glass
Mix well the coffee and the water in the bowl
After mixing correctly the coffee with the water add 160mL of methylene
chloride
Tear 1:00 all the substances in the bowl
Wait 5 minutes
After waiting 5 minutes you will noticed that you have 3 layers the first one
will be the caffeine that the coffee contain the second one is the coffee and
the third is the methylene chloride, since the caffeine is on top of everything
you will take a water dropper and take out all of the first layer.
Then measure how much mL the liquid has, after measuring the liquid you
can say that the amount of mL in the liquid is the amount of caffeine that the
coffee contain.
Ethyl acetate
1.
2.
3.
4.
5.
6.
7.
8.
1.
2.
3.
4.
Take a cup of water and put it on the glass bowl
Take 2 table spoons of coffee and put it on the bowl of glass
Mix well the coffee and the water in the bowl
After mixing correctly the coffee with the water add 160mL of methylene
chloride
Tear 1:00 all the substances in the bowl
Wait 5 minutes
After waiting 5 minutes you will noticed that you have 2 layers the first
one is the ethyl acetate with the caffeine and the second one is the
coffee, since the caffeine is on top of everything you will take a water
dropper and take out all of the first layer.
Then measure how much mL the liquid has, after measuring the liquid
you can say that the amount of mL in the liquid is the amount of caffeine
that the coffee contain.
Water
First take a glass bowl and put inside the bowl 350 g of green coffee beans
Then take 300mL of water and put them inside the bowl with the coffee
beans.
After putting both things in the bowl count 45 min and wait until seeing a
brown color as the first layer in the bowl
After waiting 45 min take a water dropper and take all the brown water. And
measure the amount of water in that quantity, after measuring that quantity
you can tell that, that is the caffeine extracted from the green coffee beans.
Methylene chloride:
Ethyl acetate:
Water:
Results:
Conclusion & Discussion:
Our hypothesis was correct because since the kPa of ethyl is much higher than
methylene chloride and water the process will be much better for decaffeinate
coffee. If you use ethyl acetate for decaffeinate coffee you will extract much more
caffeine from the coffee but if you use methylene chloride or water the process will
not be same and will have the same purity of caffeine that if you use ethyl acetate.
References:
www.stats.oecd.org Article: general statics
http://water.usgs.gov Article: water, the universal solvent
http://www.npi.gov.au article: Dichloromethane
https://www.sweetmarias.com/natural.decaf.html Article: coffeeidential