For many diners who enjoy beans, the side effects can be somewhat unpleasant--the legumes are notorious for causing flatulence. But the results of a new study indicate that beans need not lead to gas. Findings published in the July issue of the Journal of the Science of Food and Agriculture indicate that natural fermentation can remove nearly all of the compounds known to cause flatulence.

Two components of beans, alpha-galactosidic compounds and soluble dietary fiber, are thought to cause intestinal troubles when they are broken down by bacteria and produce gas as a by-product. A team led by Marisela Granito of the Food Analysis Laboratory at Simon Bolivar University in Venezuela tested the effects of fermentation--a reaction in which complex organic compounds are split into relatively simple substances--on dry beans. They tested two types of fermentation: a controlled version, in which yeast is first added to the beans, and the natural variety, which proceeds without the addition of yeast. They found that controlled fermentation removed 11 percent of stachyose (the main alpha-galactosidic in beans) after 96 hours. Natural fermentation, meanwhile, reduced the concentration of stachyose by 72 percent after 48 hours and 95 percent after 96 hours.

The natural fermentation process also lowered the beans' soluble dietary fiber content significantly in 48 hours. Thus, beans fermented prior to packaging could be easier to eat. Granito notes, "Natural fermentation also has positive effects on protein digestibility, texture and aroma, making it a very favorable method to use." So pass the beans.