Present status on removal of raffinose family oligosaccharides - a Review

Abstract

Raffinose family oligosaccharides (RFOs) are α-galactosyl derivatives of sucrose or glucose. They are found in a large variety of seeds from many different families such as beans, vegetables and whole grains. Due to absence of α-galactosidase in the digestive tract of humans and other monogastric animals, RFOs are responsible for intestinal disturbances (flatulence) following the ingestion of legume-derived products. Structural relationships of RFOs and their enzymatic degradation mechanism are described. Concentration and distribution from various seed sources are introduced. The present status on removal of the RFOs (such as soaking, cooking, germination, and addition of α-galactosidase) is summarized. At the meantime, α-galactosidases from botanic and microbial sources and their partial enzymatic properties are also presented in detail. Based on a comparison of various removal treatments, the microbial α-galactosidases are thought as the most optimum candidate for removing RFOs in legumes, and the ideal system for the RFO removal is proposed.