Cereal Chem 68:372-375   |  VIEW ARTICLE

Comparison of the Effects of Microwave and Conventional Cooking on Starch and Beta-Glucan in Rolled Oats.

S. H. Yiu, J. Weisz, and P. J. Wood. Copyright 1991 by the American Association of Cereal Chemists, Inc. 

Rolled-oat porridge was prepared by conventional and microwave cooking to determine and compare the effects of these cooking methods on the texture, viscosity, and amount of dispersed gelatinized starch and solubilized (1-3)(1-4)-beta-D-glucan (beta-glucan). The porridge prepared by microwave cooking was generally more grainy and less viscous than that prepared by the conventional method. Microwave cooking produced relatively less dispersed gelatinized starch and less solubilized beta-glucan than did conventional cooking. The difference was slight with short cooking duration (1 min) but increased drastically with prolonged cooking (20 min). Thicker oat flakes (regular-cooking rolled oats) released less solubilized beta- glucan and gelatinized starch than did thinner oat flakes (quick-cooking rolled oats) upon cooking. Microscopic examination revealed that the two cooking methods had different effects on the structural organization of oats. Rolled oats prepared by microwave cooking contained starch granules that were smaller in volume and less convoluted in structure than those conventionally cooked. Furthermore, the cell wall of the former was less disrupted. These differences may have been due to the effect of stirring; the microwave-heated rolled oats were stirred relatively less than were the conventionally cooked samples.