The effects of extrusion on the content and properties of dietary fibre components in various barley cultivars

Five Czech spring barley wholemeal flours were processed in a single-screw extruder at 130 °C, addition of 20% water and a screw speed of 220 rpm. Two barleys (AF Cesar, AF Lucius) were hulless cultivars with a normal starch composition, while three barleys (KM 2624, KM 2460-1, KM 2460-2) were hulled waxy lines. The effect of extrusion on content of different dietary fibre fractions was determined. Also the changes of the molar mass of β-glucan were studied. Regardless of the barley genotype, the extrusion had no significant effect on the β-glucan and arabinoxylan content. The content of insoluble dietary fibre decreased in extruded flour from barley AF Cesar, KM 2624, KM 2460-1 and AF Lucius. Otherwise the soluble dietary fibre content increased in KM 2624, KM 2460-1 and AF Lucius, while a decrease was observed in AF Cesar and KM 2460-2.