The reduced insulin responses in noodles treated with b-glucan (conN and 30BFN) are attributed to the decrease in the rate of postprandial glucose absorption. Oat b-glucan belongs to a type of soluble fibre which swells and gradually dissolves in water and forms pseudoplastic viscous solutions. The viscous solution may reduce activities of gastrointestinal enzymes, including amylase, lipase and chymotrypsin, towards their substrates and also retard absorption of nutrients which include plasma glucose (Lund, Gee, Brown, Wood, & Johnson, 1989). Compared with soluble fibre, insoluble fibre showed less effect in reducing the glycaemic response.