Removing healthy ginseng’s bitter bite

U. ILLINOIS (US) — Ginseng—a common ingredient in energy drinks is desired by consumers—but its bitterness is a turn-off. Now scientists have found a way to mask the acerbic aftertaste while keeping the health benefits.

“Consumers like to see ginseng on a product’s ingredient list because studies show that it improves memory, enhances libido and sexual performance, boosts immunity, and alleviates diabetes,” says Soo-Yeun Lee, associate professor of food science and human nutrition at the University of Illinois.

“But the very compounds that make ginseng good for you also make it taste bitter,”

In an earlier study, Lee and Shelly J. Schmidt, professor of food chemistry, found that ginseng contributes more to the bitter perception in energy drinks than caffeine, an indispensable component of these beverages and the very compound that sensory scientists use as their reference for bitter perception.

“Ginseng has over 30 bitter compounds, and scientists still don’t know which compound or group of compounds is responsible for the bitter taste,” Lee says.

While experimenting with five possible solutions to ginseng’s bitterness problem, they discovered that cyclodextrins—hydrophobic compounds made of glucose molecules that occur in a ring form—were able to capture the bitter flavor compounds and reduce bitterness by more than half.

Details appear in the Journal of Food Science.

Lauren Tamamoto, a graduate student who worked on the study, assembled a group of 13 non-smokers who also lacked allergies that would affect their bitter perception.

Panelists had to be able to detect a chemical called 6-n-propyl-2-thiouracil (PROP) on a piece of filter paper (some people can, some people can’t) and also pass basic taste tests for sweet, sour, bitter, and salty perceptions.

They then participated in 12 training sessions and taste-tested 84 samples, rating each on a 16-point scale.

The researchers used the panelists to test five potentially effective bitterness-reducing treatments.

“Cyclodextrins were by far the most effective method of reducing the bitterness of ginseng solutions. We also found that gamma-cyclodextrins were more successful than beta-cyclodextrins and were more cost-effective,” Schmidt says.

These compounds have been used to mask bitterness before, but not at the level of ginseng used in a typical energy drink, she says.

Lee and Schmidt intend to continue studying ginseng’s bitterness compounds to learn which are most responsible for producing objectionable flavors, and to gain insight into exactly how these compounds interact with cyclodextrins in order to facilitate the use of ginseng as a functional ingredient in energy drinks and allow manufacturers to add health benefits to the beverages beyond general nutrition and the calories they provide.

“The U.S. energy drink industry is expected to reach $19.7 billion in sales by 2013, even though these beverages often have a medicinal taste because of their functional ingredients.

“If we can create more palatable products, manufacturers will be able to expand this market even further,” Lee says.

“But, beyond that, this new method for masking bitterness in ginseng gives food scientists an opportunity to improve the health of consumers.”

More news from University of Illinois: http://news.illinois.edu/