stachyose

Stachyose is a tetrasaccharide and a member of the raffinose family of oligosaccharides (RFOs). It is composed of two galactose units linked to a disaccharide made of glucose and fructose, giving it the overall composition of two galactose residues, one glucose, and one fructose. Like other RFOs, stachyose is a carbohydrate found in a variety of plant foods.

Natural occurrence and dietary sources: stachyose occurs in seeds and plant tissues of many legumes and cereal crops. Foods rich in stachyose include beans, lentils, chickpeas, soybeans, and certain other legumes, as well as some vegetables and whole grains. Its content can vary with plant species, variety, and processing.

Digestion and health aspects: humans generally lack the enzyme alpha-galactosidase needed to break down stachyose in the small intestine. As a result, it passes into the colon where gut bacteria ferment it, producing gases such as hydrogen and methane. This fermentation can contribute to flatulence and bloating in some individuals. Stachyose can also act as a fermentable carbohydrate contributing to the growth of certain beneficial gut bacteria, a characteristic common to prebiotic dietary components.

Processing and reduction: methods such as soaking, cooking, sprouting, fermentation, or enzymatic treatment can reduce stachyose content in foods. These approaches are commonly used to lessen flatulence while preserving other nutrients.

Safety and overview: stachyose is not considered toxic and is part of a broader class of dietary oligosaccharides. Its effects on health are largely related to gut fermentation and compatibility with individual tolerance.