Enrichment of β-glucan in oat bran by fine grinding and air classification

Abstract

Oats contain soluble dietary fiber, a major component of which is β-glucan. Oat bran is an oat dry milling fraction enriched in β-glucan. Our objective was to optimize β-glucan enrichment from oat bran by an inexpensive method. The defatted oat bran was ground 1 × 9,000, 1 × 14,000, or 3 × 14,000 rpm in a pin mill. Analysis of β-glucan for fine and coarse fractions for each milling speed indicated the highest β-glucan content was obtained in fractions larger than 30 μm from 3 × 14,000 rpm. This fraction accounted for 393g/kg of defatted oat bran, and it contained 188 g/kg β-glucan and 302 g/kg protein. With further fractionation of this fraction by sieving, it was observed that fractions of particle size greater than 90 μm contained 200g/kg β-glucan and less than 100 g/kg of starch. The enriched β-glucan fraction was obtained in good yield and has commercial potential as a food ingredient or for further processing. © 2002 Elsevier Science Ltd.