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 highestβ -glucan content was obtained in fractions larger than 30 μ m from 3×14,000 rpm. This fraction accounted for 393 g/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 90μ m contained 200 g/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.