DecaffeinationBy: Myron Sailors

What is this “Decaffeination” of which you speak?of which you speak?

Decaffeination is the removal of caffeine from a substance.

It is usually associated with coffee beans and tea leaves

Why should we care about Decaffeination?

Well decaffeination is very popular among coffee drinkers who want the taste of coffee or tea, but do not want the energy that’s associated with it.

Well, how is this “process” done?

Well there are many different ways

French water process

Chemical extraction method

Supercritical fluid method

Swiss water method Above: Caffeine Molecule

Could you explain the French Water Process?

This process uses equilibrium the most of all the processes.

The beans are soaked in water for over 24 hours. The water acts as a solvent and the caffeine shifts from the bean to the water to achieve equilibrium.

The beans are dried whilst the water is run through a charcoal filter. The caffeine has a greater attraction to the charcoal than the water and coffee solids in the water.

The beans are then returned to the 99.9% caffeine-free water

(Stardivant)

Interesting, what about the Chemical Extraction Method?

In the chemical extraction process, the beans are first soaked in water to soften the beans.

The beans themselves are then soaked in one of two organic solvents. The beans can be soaked in dichloromethane (CH Cl ) or ethyl acetate ₂ ₂(CH CO C H ).₃ ₂ ₂ ₅

The solvent removes the caffeine. Once it does so, the beans are treated with steam. The solvent and the caffeine evaporate out of the beans.

(Barstow 1)Left: Dichloromethane

Right: Ethyl acetate

That’s nice, tell me more about this “Supercritical fluid” method.

This process is probably the most interesting.

CO is heated and pressurized. The CO ₂ ₂reaches its supercritical state.

The supercritical CO is passed through the ₂coffee. When it passes through the coffee it dissolves the caffeine.

The CO is passed through a pressure ₂reduction valve and the caffeine precipitates and the CO is collected to be used again.₂

(Barstow 2)

Yo Myron, don’t forget about the Swiss Water Process.

Ok, if you insist.

This is probably the easiest to find information about.

The beans start off soaking in water when a solvent is added to the water.

The beans are then removed from the water and the water is then passed through a carbon filter.

The water is the added to the beans. This process is repeated until the beans are 99.9% caffeine free. The total time is 8-10 hours.

http://www.youtube.com/watch?v=fHba09QKOi0&feature=player_embedded

(“Decaffeination”)

Work Cited

Barstow, Kimberly. "The Case of the Missing Caffeine." ChemMatters April (1999): 12-13.

Print.

"Decaffeination." Restaurant Business Dec. 2005: 90. General OneFile. Web. 6 Apr. 2013.http://go.galegroup.com.candycorn.lipscomb.edu/ps/i.do?id=GALE%7CA140408951&v=2.1&u=tel_k_dlhs&it=r&p=GPS&sw=w

Sturdivant, Shea. "French water process decaffeination." Tea & Coffee Trade Journal Sept. 1992: 31+. General OneFile. Web. 29 Apr. 2013.

http://go.galegroup.com.candycorn.lipscomb.edu/ps/i.do?id=GALE%7CA12686245&v=2.1&u=tel_k_dlhs&it=r&p=GPS&sw=w

Work Cited

Barstow, Kimberly. "The Case of the Missing Caffeine." ChemMatters April (1999): 12-13.

Print.

"Decaffeination." Restaurant Business Dec. 2005: 90. General OneFile. Web. 6 Apr. 2013.http://go.galegroup.com.candycorn.lipscomb.edu/ps/i.do?id=GALE%7CA140408951&v=2.1&u=tel_k_dlhs&it=r&p=GPS&sw=w

Sturdivant, Shea. "French water process decaffeination." Tea & Coffee Trade Journal Sept. 1992: 31+. General OneFile. Web. 29 Apr. 2013.

http://go.galegroup.com.candycorn.lipscomb.edu/ps/i.do?id=GALE%7CA12686245&v=2.1&u=tel_k_dlhs&it=r&p=GPS&sw=w