While dry beans and legumes are considered a healthy alternative to high fat sources of protein, the discomfort felt by many after consuming them is a growing concern. Consumption of beans has been decreasing in most western diets, mostly attributed to this discomfort and to the social stigma of passing gas. For the bean lovers out there, you are not forgotten! Scientists are looking for ways to reduce the negative factors resulting from digesting beans.

In a study from Venezuela1, researchers set out fermenting beans with the hope of reducing the concentrations of alpha-galactoside and soluble fibre, the two main known flatulence producers found in beans. Previous studies have shown that in addition to reducing gas production, fermentation of beans provides greater bioavailability of the nutrients contained within them.

The researchers used two main methods to examine beans undergoing fermentation: natural fermentation (NF), fermented with a grain; and controlled fermentation (CF), fermented with a commercial starter normally used in the production of yoghurt. In both cases, the beans had to be ground into a paste for study. They tested the paste at 24, 48, 72, and 96 hours. After 48 hours, the NF beans had an apparent removal of all the soluble fibre, and CF beans had reduced soluble fibre concentrations of 66% at 96 hours. The concentration of stachyose, the alpha-galactoside, in NF beans was reduced by 72% at 48 hours and 95% at 96 hours, and in CF beans, only by 11% at 96 hours. According to the researchers, the natural fermentation process seems to be the more effective of the two processes for reducing the gas producing substances. The only downside was that after fermentation for 96 hours, the beans became unpalatable.

More research is needed to produce a product that individuals would actually enjoy eating, while gaining the added nutritional benefits from the fermentation process. Until then, products that help reduce flatulence from eating beans are over-the-counter pills such as Beano® and Digesta®.

First published in the Inside Tract® newsletter issue 146 – November/December 2004
1. Journal of the Science of Food and Agriculture; 83: 1004-1009