Effects of roller and hammer milling on the yield and physicochemical properties of fibre-rich fractions from biofortified and non-biofortified hull-less barley

This study was carried out to compare fibre-rich fractions (FRF) yields of two milling systems from hull-less barley cv. Yalin with and without biofortification (Yalin (+) and (-)) and investigate effect of biofortification (Zn, I, Se) on composition and physicochemical properties of fractions. Biofortification increased Zn, I, Se contents considerably. FRF yields of roller mill (FRFR) were 55.2 and 56.2 g/100g while those of hammer mill (FRFH) were 43.7 and 45.9 g/100g for Yalin (-) and Yalin (+), respectively. Pin-milling was applied for further enrichment. The yields of enriched fraction E-FRFR were 25.9 and 26.0 g/100g while yields of enriched fraction E-FRFH were 22.8 and 24.1 g/100g for Yalin (-) and Yalin (+), respectively. Beta-glucan contents of FRFR were 7.20 and 6.91 g/100g while those of FRFH were 8.91 and 8.09 g/100g for Yalin (-) and Yalin (+), respectively. Similarly, beta-glucan contents of E-FRFR were 12.91 and 12.33 g/100g while those of E-FRFH were 14.17 and 13.02 g/100g for Yalin (-) and Yalin (+), respectively. Enrichment increased RVA viscosities, porosities and decreased bulk densities, mass median diameters and dispersions. It can be concluded that barley grains that underwent biofortification can also be employed to give beta-glucan enriched milling fractions.