General Information: Raffinose is a trisaccharide composed of galactose, fructose, and glucose. It can be found in beans, cabbage, brussels sprouts, broccoli, asparagus, and other plants. In plants, raffinose is generated via binding of galactinol (a sugar alcohol) to sucrose. Raffinose has only 20 % of the sweetening intensity of sucrose.
Dietetics: Raffinose can be hydrolyzed to sucrose and galactose by the enzyme α-galactosidase (α-GAL). Humans do not possess the α-GAL enzyme in their small intestine to break down the trisaccharide. Thus bigger amounts of raffinose reach the large intestine, where bacteria of the gut flora perform the break down and produce gases. This may cause flatulence. Due to its indestigibility, raffinose is sometimes used in foods to reduce calories.
Legumes in a market place in Italy
|Chemistry: The raffinose family of oligosaccharides (RFOs) are alpha-galactosyl derivatives of sucrose.|
|Most common are the trisaccharide raffinose, the tetrasaccharide stachyose, and the pentasaccharide verbascose. RFOs are almost ubiquitous in the plant kingdom, being found in a large variety of seeds from many different families, and they rank second only to sucrose in abundance as soluble carbohydrates. In some plant families starch as an energy storage is replaced by oligosaccharides like raffinose. The sugar beet is producing raffinose as antifreezing agent.
Usage: Legume seeds (peas, beans, lentils) contain 5 to 15 % raffinose in their dry weight. During the production of beet sugar, major amounts of raffinose accumulate in the molasses, which can be used to produce some kinds of brown sugars. Technically, raffinose can be used as a antifreezing agent (freezing medical preparates, cryopreservation).