This article explains the scientific principles and supercritical fluid processes that allow decaffeinated coffee to retain its flavor without the stimulus of caffeine. It also explores the potential for this technology to be used in a variety of food processing and environmental applications beyond coffee.
On my way home from class, I pass many coffee shops, including Starbucks. In the hustle and bustle of the city, coffee shops are perhaps our respite. Like tired office workers on their way home from work or college students finishing up their classes, I naturally stop in front of a café to smell the aroma of coffee. When I grab a cup of coffee to take a break, I feel like my day is complete.
I walk past so many cafes that the aroma of coffee stops me in my tracks. The varied menus and stylish interiors tempt me, and I can’t resist. Everyone has their own coffee preferences. Some prefer a strong espresso, others a smooth latte. I tend to choose my coffee based on my mood for the day. Today, I’m in the mood for a sweet caramel macchiato, so I place my order and look around as I wait for my coffee to arrive. With a cup of coffee in hand, the world suddenly seems a little more relaxed.
I order a cup of coffee, take a picture, and post it on Instagram. Socializing on social media has become an important part of my daily routine. I share the small moments of my life and create my own little world. This is one of those moments when I take a moment to relax with a cup of coffee. I return home feeling satisfied and head to bed early to get ready for tomorrow. But I can’t fall asleep easily because of the coffee I drank during the day. I toss and turn, finally falling asleep, and don’t wake up refreshed to face the next day.
To combat the morning drowsiness, I grab a coffee milk from the convenience store and head to class. The senior next to me sneaks in a comment. “Why don’t you try decaf coffee? If caffeine is keeping you awake, it’s worth a try.”
Decaffeinated coffee is coffee that has been decaffeinated by more than 97% for people who want to reduce their caffeine intake while still enjoying the taste and aroma of coffee. These days, you can find a variety of decaf options at cafes. First developed in the 1970s, decaffeinated coffee has become increasingly simple to make, lower in price, and steadily increasing in consumption. Many people think of caffeine when they think of coffee, but nowadays, decaffeinated coffee is no longer the only option for health-conscious people.
So how does decaffeinated coffee retain its flavor? In addition to caffeine, coffee beans contain many other chemicals. Only by selectively extracting caffeine from these chemicals is decaffeinated coffee made. The key to this technology that removes caffeine while leaving the taste and aroma intact is the ‘supercritical fluid process’.
The supercritical fluid process combines various scientific principles to selectively extract only caffeine from coffee beans. We’ve been learning about the states of matter since elementary school: solid, liquid, and gas, but at certain temperatures and pressures, matter can exist in another form called the supercritical state. In this state, a substance has the properties of both a liquid and a gas, which is how we extract caffeine from coffee.
In particular, when carbon dioxide reaches the supercritical state, it is used as a solvent to dissolve substances like caffeine. Carbon dioxide selectively dissolves only caffeine and does not affect the compounds that determine the taste and aroma of coffee. As a result, we can enjoy the flavor of coffee without the stimulation of caffeine.
This technology doesn’t just apply to coffee. Supercritical fluidization is also used in the processing of various food products, such as sesame oil or rice bran. It is also being used in a variety of environmental applications, such as detergent-free dry cleaning and wastewater treatment technologies.
The potential of supercritical fluid technology is enormous. However, the cost of commercializing the technology remains an issue. Nevertheless, researchers are still working to find new materials and methods in anticipation of the revolutionary changes this technology will bring. I used to think decaffeinated coffee was just decaffeinated coffee, but after learning the science behind it, I started to enjoy it a little more.
Now, every time I drink coffee, I think about the complex process behind it. It’s fascinating to realize that there’s a lot of cutting-edge technology behind the little bit of tranquility that a cup of decaf coffee brings. I start my day with the smell of coffee, realizing that a cup of coffee, which is always by my side, has so many stories to tell.
