About My Health Careers Internship MedBlogs Contact us
Medindia LOGIN REGISTER
Advertisement

Roasting of Beans Gives Bitterness to Coffee: Study

by Jayashree on August 22, 2007 at 5:28 PM
Font : A-A+

Roasting of Beans Gives Bitterness to Coffee: Study

In a discovery that could lead to better tasting coffee, chemists report finding the compounds that are most responsible for the drink's bitter taste.

Using chemical analyses and follow-up taste tests by humans trained to detect coffee bitterness, chemists in Germany and the United States have discovered the compounds that make coffee bitter and also how they form.

Advertisement

'Everybody thinks that caffeine is the main bitter compound in coffee, but that's definitely not the case,' said study leader Thomas Hofmann, a professor of food chemistry and molecular sensory science at the Technical University of Munich in Germany.

Just 15 percent of coffee's bitter taste comes from caffeine, said Hofmann, who presented his findings at a meeting of the American Chemical Society in Boston.
Advertisement

Using advanced chromatography techniques and a human sensory panel trained to detect coffee bitterness, Hofmann and his associates found that coffee bitterness is due to two main classes of compounds: chlorogenic acid lactones and phenylindanes, both of which are antioxidants found in roasted coffee beans. The compounds are not present in green (raw) beans, the researchers note.

Chlorogenic acid lactones, is present at high levels in light- to medium-roast brews. Dark roasts, such as espresso, showed high levels of phenylindanes, which form when the chlorogenic acid lactones break down and give a more lingering, harsh taste than their precursors, Hofmann said.

'We've known for some time that the chlorogenic acid lactones are present in coffee, but their role as a source of bitterness was not known until now,' Hofmann says.

'Roasting is the key factor driving bitter taste in coffee beans. So the stronger you roast the coffee, the more harsh it tends to get,' Hofmann added.

He further said that prolonged roasting leads to the formation of the most intense bitter compounds found in dark roasts.

How the beans are brewed also affects bitterness, the scientists found. The high pressures and temperatures used for brewing espresso-type coffees produce the highest levels of bitter compounds.

'Now that we've clarified how the bitter compounds are formed, we're trying to find ways to reduce them,' Hofmann said.

Hofmann and his associates are currently exploring ways to specially process the raw beans after harvesting to reduce their potential for producing bitterness. They are also experimenting with different bean varieties in an effort to improve taste.

Source: ANI
JAY/J
Advertisement

Advertisement
News A-Z
A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
Advertisement
News Category
What's New on Medindia
Western Diet may Augment the Risk of Autoimmune Diseases
Black Tea Protects against Blood Pressure and Heart Diseases
Green Mediterranean Diet may Help Repair Age-Related Brain Damages
View all

Medindia Newsletters Subscribe to our Free Newsletters!
Terms & Conditions and Privacy Policy.

More News on:
Top Ways to Cook Vegetables 

Recommended Reading
Coffee-exercise Combo can Prevent Skin Cancer
Drinking coffee and exercising may prevent skin cancer by killing off cells damaged by the sun's ......
Drinking Coffee Reduces Risk of Liver Cancer
A new study has revealed that coffee consumption reduces the risk of HCC (hepatocellular carcinoma) ...
New Coffee Brand to Hit the Market by This Year-end
The Balehonnur-based Central Coffee Research Institute (CCRI) has said that it will announce a new ....
Top Ways to Cook Vegetables
While salads are a healthy choice, eating cooked veggies are equally important since they can be coo...

Disclaimer - All information and content on this site are for information and educational purposes only. The information should not be used for either diagnosis or treatment or both for any health related problem or disease. Always seek the advice of a qualified physician for medical diagnosis and treatment. Full Disclaimer

© All Rights Reserved 1997 - 2022

This site uses cookies to deliver our services. By using our site, you acknowledge that you have read and understand our Cookie Policy, Privacy Policy, and our Terms of Use
open close
ASK A DOCTOR ONLINE
I have read and I do accept terms of use - Telemedicine

Advantage Medindia: FREE subscription for 'Personalised Health & Wellness website with consultation' (Value Rs.300/-)