Variability of carbohydrate composition and pasting properties of oat flakes and oat flours produced by industrial oat milling process – Comparison to non-heat-treated oat flours

Abstract

This study characterised the starch and dietary fibre properties and their significance to the pasting characteristics of oat flakes and flours produced from 30 Finnish pure cultivar oats with or without the industrial scale milling process. Large variation in carbohydrate characteristics was observed, the insoluble dietary fibre content of flours was 2.4–5.7 % and soluble dietary fibre was 4.9–8.0 %. The oat milling process induced a significant amount of starch damage (p < 0.05), a fourfold increase from 1 % to 4 % in average was observed. The pasting properties of both flakes and flours were interlinked (p < 0.05) with the chemical composition of oats, i.e., high starch content of flours was connected to higher paste viscosity values. The milling process increased the peak, trough, setback, final and time to peak viscosities of oat flours. These results show the significance of oat milling process, including kilning, to the carbohydrate quality of oats.