Introduction
Composition of ...
Per weight coffee is made mainly of polysaccharides. Polysaccharides are a type of carbohydrate. In unroasted coffee the second most common compound are lipids. Lipids are compounds that are mostly insoluble in water, things like fats and oils. In roasted coffee the second most common compound comes from caramelization, caramelization is a non enzymatic browning reaction that causes the oxidation of saccharide. One of the chemicals that many people associate with their cup of joe is caffeine. Caffeine is a purine alkaloid, and it’s chemical composition is C8 H10 N4 O2. Another of coffee’s interesting components are acids. Acids in coffee greatly affect the flavor of it and how it feels in your mouth when you drink it. Among the acids are acetic, citric, formic, malic, fumaric, and others.
Main Chemicals, Compounds, Components
The two main chemicals in coffee are polysaccharides and lipids.
Chemistry's Role
Chemistry is involved in coffee because environmental factors in growing the coffee, such as humidity, pH of the soil, and location. Also the length that coffee is roasted changes it’s chemical properties, and it’s flavor. If one roasts it too short it is very acidic, and rather bad tasting, but when it’s properly roasted it has the chemical composition that many of us know and love. When coffee is roasted, the beans go through the caramelization process. Caramelization is the process in which polysaccharides are oxidized, and it’s a non enzymatic browning process. The byproducts of caramelization are carmelen, which has a chemical formula of C36H50O25, caramelan, which has a chemical formula of C12H18O9, and caramelin, which has a chemical formula of C125H188O80. Oxidation also somewhat changes the color of coffee, along with the beans slowly turning into charcoal.
Background Research
Coffee is grown in the bean belt which goes between the tropic of cancer and the tropic of capricorn. The bean is then taken and dried, where it is shipped to roasting facilities. These roasting facilities roast it, bag it, and sometimes grind it for you. Then it is your job to take the coffee, if it’s whole bean, grind it, but if not, roast it and enjoy.
Resources
http://www.jlhufford.com/articles/whatiscoffee.asp
Chemical Composition of Coffee
Chemical composition of coffee by weight.
http://www.sciencenews.org/view/generic/id/340733/title/Coffee_gives_jolt_to_life_span
Health benefits of coffee
http://www.blackriverroasters.com/the-science-of-coffee/
explains lipids of coffee, caffeine a bit, and goes lightly into how the robusta and arabica beans are different.
http://www.vittoriacoffee.com/
Has about coffee going from bean to tree, stuff about it’s grinding, it also mentions arabica vs robusta and the latitudes where they grow.
http://www.sweetmarias.com/coffee.other.robusta.php
This talked a lot about robusta beans, and what the difference is with them and arabica.
http://www.rpi.edu/dept/bcbp/molbiochem/MBWeb/mb1/part2/sugar.htm
This talked about sugars and polysaccharides.
http://www2.chemistry.msu.edu/faculty/reusch/VirtTxtJml/lipids.htm
Lipids
http://www.scienceofcooking.com/caramelization.htm
information on caramelization
http://lifehacker.com/5986506/the-science-behind-coffee-and-why-its-actually-good-for-your-health
Coffee’s health effects.
http://www.wired.com/science/discoveries/magazine/17-10/st_coffee
What’s inside coffee
http://www.coffeeresearch.org/science/sourmain.htm
acids
http://www.britannica.com/EBchecked/topic/15672/alkaloid
Alkaloids
http://0.tqn.com/d/chemistry/1/7/-/B/1/arabinose.jpg
visual reference for arabinose
http://www.scienceofcooking.com/maillard_reaction.htm
Malliard Reaction.
About the Author
Matthew Hanson is a senior at Billings Senior High School. He loves coffee, playing clarinet, and spending time on computers. Next year he will attend Montana State University to study Computer Science and in his spare time he will drink lots of coffee.