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WEDNESDAY, July 9, 2003 (HealthDayNews) -- South American scientists have found a way to knock the air out of beans so you can eat them without sending your friends fleeing.
By naturally fermenting beans for two to four days, researchers at Simon Bolivar University in Caracas, Venezuela, reduced by up to 95 percent the flatulence-causing compounds in white beans.
"We have found a simple and economic method of lowering one of the flatulence compounds most difficult to eliminate by the traditional methods of bean processing," says study author Marisela Granito.
An added benefit, she says, was that the fermentation process also increased the bioavailability of the nutrients in the bean, making it potentially more nutritious.
The results of the study appear in the July issue of the Journal of the Science of Food and Agriculture.
"People have some 'turbulence,' shall we say, when they eat beans, and I'm sure they avoid them because of their antisocial consequences," says Maureen Storey, director of the Center for Food and Nutrition Policy at Virginia Tech University. "But beans are a wonderful source of low-fat protein, so anything that can encourage people to eat more beans is a good thing."
For the study, Granito and her colleagues used a natural fermentation process to see if they could reduce a type of compound in beans called a-galactosides that is known to increase flatulence. They also looked at reducing soluble dietary fiber, which is also associated with flatulence.
The beans, which had been ground into flour, were put into 10 sealed glass containers that held distilled water, and they were fermented for 24, 48, 72, and 96 hours, respectively. They found the fermentation removed all the soluble fiber. The a-galactosides were reduced dramatically, by 72 percent after 48 hours to 95 percent after 96 hours.
Also improved was the nutritional value of the beans, the study reported, By breaking down formerly indigestible compounds, the nutritional components of the bean, including vitamin B2, would be more readily absorbed in the body.
April Mason, a professor of nutrition at Purdue University who has done similar research on beans and flatulence, finds interesting the study's finding that soluble fiber produces gas. "Iit's mostly associated with insoluble fiber, which gets to the lower GI tract and ferments there, which causes the gas," Mason says.
But she says that 96 hours is too long to ferment the beans if you want a final product that someone will eat.
"It's pretty odiferous, at least when wet, and gets a tart taste because there's a lot of acid in the product," she says. "You want to be sure, if you're doing this, that people are going to eat it."
Trying to get the gas out of beans has been a goal of scientists since the beginning of the republic, according to Walter Issacson's new biography of Benjamin Franklin, which reports that the inventor -- perhaps with tongue in cheek -- recommended experiments to try reduce flatulence in beans.
Currently, there is one product called Beano, manufactured by the London-based pharmaceutical company GlaxoSmithKline, that promises relief by taking pills along with gas-producing meals to reduce flatulence.
"Whatever companies can do to reduce the social factors relating to beans can only help," Storey says.
More information
The National Digestive Diseases Information Clearing House has an understandable explanation of how gas forms in the digestive tract. More information on bloating and belching can be found at the American College of Gastroenterology.
