Effect of Cooking and Storage on the Amount and Molecular Weight of (1→3)(1→4)‐β‐<scp>d</scp>‐Glucan Extracted from Oat Products by an In Vitro Digestion System

Abstract

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