Publication no. C-1997-1025-03R |  VIEW ARTICLE

Effect of Cooking and Storage on the Amount and Molecular Weight of (1-3)(1-4)-beta-D-Glucan Extracted from Oat Products by an In Vitro Digestion System (1).

Michael U. Beer (2), Peter J. Wood (2,3), John Weisz (2), and Nicole Fillion (2). (1) Contribution 2423 of the Centre for Food and Animal Research, Agriculture and Agri-Food Canada, Ottawa. (2) Centre for Food and Animal Research, Agriculture and Agri-Food Canada, Ottawa, Ontario, K1A 0C6, Canada. (3) Corresponding author. E-mail: <WoodP@EM.AGR.CA> Cereal Chem. 74(6):705-709. Accepted June 27, 1997. Copyright 1997 Department of Agriculture and Agri-Food, Government of Canada.

The extractability and molecular weight of beta-glucan in oat bran, oat bran muffins, and oat porridge and the changes taking place during processing and storage were studied. The beta-glucan was extracted using hot water and a thermostable alpha-amylase and by an in vitro system that simulated human digestion. Molecular weight (MW) of the extracted beta-glucan was determined using high-performance size-exclusion chromatography. Hot-water treatment extracted 50-70% of total beta-glucan in oat bran samples and rolled oats. The chromatographic peak MW of extracted beta-glucan was in the 1.4-1.8 × 10(^6) range. Using the in vitro digestion system, 12-33% of total beta-glucan in bran and rolled oats was solubilized, and peak MW was in the same range as beta-glucan extracted by hot-water treatment. In muffins, 30-85% of total beta-glucan was solubilized by in vitro digestion, with a major difference in extractability among muffins from different recipes. Peak MW of extracted beta-glucan was lower in all muffins when compared to original bran. During frozen storage, extractable beta-glucan decreased by >50% in all muffins, but no change in peak MW of extracted beta-glucan was detected.