What are the different Coffee aroma compounds found in coffee?
For starters, each cup of coffee is a complex brew made up of thousands of different natural chemicals. However, only a few of these are responsible for the myriad flavors and aromas found in your morning joe. Just 44 chemicals contribute the bulk of nuance and depth to espresso or cold brew. The minuscule variations in the chemistry of coffee compounds account for the differences in flavor between different beans and roasts.
Coffee appeals to all the senses. However, the most utilized are smell and taste. The primary focus of coffee farmers and roasters is to optimize the flavor and aromas of the coffee beans. Optimizing the flavor of coffee is done by refining growing and processing conditions to produce the most satisfying cup of coffee. This delicate process involves controlling temperature, moisture, light, other factors, and coffee with ideal natural chemical profiles. If the producer takes the correct steps to optimize flavor, consumers to fully enjoy their coffee without the addition of artificial flavors that hide the biological complexity of the beans.
Roasting Coffee Beans for Flavor and Aroma
The roasting process requires a lot of control and precision and the size of the roaster affects the outcome of which aromatic coffee compounds will be detected. Coffee roasters who want to produce specialty coffee use smaller roasters 15 kg and smaller. Smaller roasters are essential to successful specialty coffee roasting because the smaller the coffee roaster, the more control operators have over the roast and the chemistry of coffees flavor.
Table 1. Capacity in grams and quantity in coffee beans with the size of the coffee roaster.
Capacity in gms
Quantity in number of beans
Small Roaster (5 kg)
Medium Size Coffee Roaster (15 kg)
Small Factory Roaster (35 kg)
Large factory Roaster 280 (kg)
Coffee Aroma And Flavor
Coffee aromas include an array of scents, both good and bad. First, after roasting coffee, volatile organic compounds can be detected by the nose. The pleasant coffee smells can include aromas of fruit, caramel, malt, spice, vanilla, honey, flowers, and mint. And on the unpleasant side, you can find odors of butter, cabbage, fish, boiled potato, phenol, burnt coffee, grease, and sulfur.
The variety of the coffee bean does make a difference in the final product. However, these ‘green’ coffee beans are just untapped aromatic potential. The roasting process unleashes the flavorful aroma compounds trapped in raw coffee beans.
Bringing To Life The Flavor Of Coffee
Grinding the roasted beans, then extracting their aromatic compounds by percolating hot filtered water through the coffee grounds results in a veritable extravaganza of coffee flavor.
Coffee can smell fruity and floral, or like caramel, nuts, and chocolate. Because these flavors originate from specific organic compounds, coffee tasters should know some aromatic compounds in roasted coffee beans.
A high amount of fermentone, for example, can give a coffee a floral or fruity scent that reminds some people of apples, pears, or plums. Fermentone is a compound responsible for the smell of several fruits and flowers.
It’s in a chemical family known as the “rose ketones” because the ketone is available in these plants in such high concentrations. Thus, coffee can smell like fruit because it has the same chemicals that smell like fruit!
Coffee Compounds and Pineapple Ketones
Coffee also naturally contains pineapple ketone, an aromatic compound that is also one of the primary scent chemicals found in pineapples and strawberries. Pineapple ketone is in the same chemical family as raspberry ketone and has been used as a supplement to promote weight loss.
Pineapple ketone has a warm, sugary smell that can remind people of caramel. However, it has the unmistakable aroma of ripe pineapple in higher amounts.
Chemistry of Coffee: Chemical Compounds of Coffee Flavors
The chemistry of coffee’s 44 organic volatile compounds is stored in the green bean and then released during the roasting process.
There are two terms for labeling and determining the potency of aromatic compounds. First, The aroma activity value (AAV) is the concentration in the product above the detection threshold. Second, the CAS registry number is a unique numerical identifier for chemical compounds, polymers, biological sequences, preparations, and alloys from the Chemical Abstracts Service.
Hans Steinhart from the University of Hamburg reported the 44 potent aromatic compounds found in Colombian Coffee. Let’s take a look at a few of these chemical coffee compounds below:
Five volatile organic compounds found in coffee
1. Fermentona (E)-β-Damascenona (C13H18O) (E)-1-(2,6,6-Trimetilciclohexa-1,3-dien-1-il)but-2-en-1-ona
- Aroma activity value (AAV):270,000
- CAS registry number: 23726-93-4
This coffee aroma is a fruity and floral compound, thus giving the flavor of coffee notes of apple, grapes, strawberries, woods, and even spiced tobacco. Apples share this compound with an AAV of 1813. Lastly, the tomato carries this compound, as does the tomato with an AAV of 500.
2. 2-Furfuriltiol (Furfurilmercaptano) (C5H6OS)
- AAV: 110,000 and CAS: 98-02-2
This compound offers a secondary use as a character impact compound frequently found in artificial coffee flavors. The characteristic odor groups include roasted coffee, floral, French vanilla, fried onion, and burnt phosphorus. Also, we see the compound in cooked beef with an AAV of 29 μg/Kg and in cooked pork 9.5 μg/Kg.
3. 3-Mercapto-3-metilbutilformiato (C6H12O2S) / Pyrazine from peppers
- AAV: 27,000 and CAS: 24683-00-9
The characteristic coffee aromas of this compound include roasted coffee, herbal, fruity notes, and caramelized onion. It appears in boiled potatoes with an AAV of 0.07 μg/Kg and fries with 8.6 μg/Kg. With a loss at room temperature at 30 minutes of 21%.
4. 2-Etil-4-hidroxi-5-metil-3(2H)-furanone (C7H10O3) / Soy furanone
- AAV 15,000 and CAS: 27538-10-9
-This aromatic coffee compound includes notes of strawberry, cotton candy, and fruit.
5. 4-Hidroxi-2,5-dimetil-3(2H)-furanone (HDF) (C6H8O3)
- AAV: 1,700 and CAS: 3658-77-3 -Strawberry Furanone or Pineapple Ketone