Influence of Jet Cooking and pH on Extraction and Molecular Weight of β‐Glucan and Arabinoxylan from Barley (Hordeum vulgare Prowashonupana)

Abstract

ABSTRACTFood processing conditions may affect the extractability and molecular weight of β‐glucans and arabinoxylans in cereal products. This can dramatically affect the functional and physiological properties of the final products. Therefore, the purpose of this research was to explore the effects of jet cooking on the content, extractability, and molecular weights of these polymers in barley flour from a high β‐glucan, waxy barley genotype, Prowashonupana. Barley flours were jet cooked without pH adjustment or after adjusting to pH 7, 9, or 11. Jet cooking without pH adjustment increased the extractability of β‐glucans from 15.4 to 38.0% when extracted with water at 30°C. As pH during jet cooking increased, the extractability further increased to 63.5% at pH 11. Arabinoxylan extractability was only substantially affected when the pH of jet cooking was alkaline (extractability increased from 11.4 to 48.5% when jet cooked at pH 11). Jet cooking without pH adjustment resulted in slight increases in peak molecular weights for both polymers (β‐glucan increased from 420,000 to 443,000; arabinoxylan increased from 119,000 to 125,000); higher pH values during jet cooking resulted in minor decrease in molecular weights.