Cereal Chem 64:373-379   |  VIEW ARTICLE

Effects of Cooking on Starch and Beta-Glucan of Rolled Oats.

S. H. Yiu, P. J. Wood, and J. Weisz. Copyright 1987 by the American Association of Cereal Chemists, Inc. 

In this study of the effect of cooking on rolled oats, oatmeal was prepared according to manufacturers' recommendations by cooking rolled oats gradually from room temperature, or rapidly by addition to boiling water. The cooked mixture was then centrifuged, and three layers were separated and analyzed chemically and histochemically. Distinct differences were observed between the two cooking methods. The gradually cooked oatmeal had more solubilized (1-3) (1-4)-beta-D-glucan and starch and had a more viscous supernatant. The solids of the gradually cooked sample were more hydrated and the middle starchy layer occupied a larger volume. Microscopic examination revealed differences in the appearance of both the cell walls and the starch of the two differently cooked samples. In general, the disruption of the endospermic cell walls of the gradually cooked sample was greater than for the rapidly cooked sample. The loss of starch granule integrity was greater in the gradually cooked sample, and the middle starchy layer showed a more open structure. Presumably all of these factors contribute to the well-recognized creamier texture of gradually cooked oatmeal. The possible relationship of these observations to the rate of digestion was examined in a model system using salivary alpha-amylase. Uncooked oatmeal was more slowly digested by salivary alpha-amylase than cooked oatmeal, but small differences observed between the gradual- and rapid- cooked samples are probably not physiologically significant.