Roller Milling of Canadian Hull-less Barley: Optimization of Roller Milling Conditions and Composition of Mill Streams

• Published in: Cereal chemistry Vol. 80; no. 6; pp. 637 - 644
• Main Authors: Izydorczyk, M.S, Dexter, J.E, Desjardins, R.G, Rossnagel, B.G, Lagasse, S.L, Hatcher, D.W
• Format: Journal Article
• Language: English
• Published: St. Paul, MN The American Association of Cereal Chemists, Inc 01.11.2003; American Association of Cereal Chemists
• Subjects: arabinoxylan; barley; beta-glucans; Biological and medical sciences; byproducts; Cereal and baking product industries; cultivars; flour; Food engineering; Food industries; Fundamental and applied biological sciences. Psychology; General aspects; grinding; milling; water content; Glucan; Barley; Pentosane; Water content; Roller mill; Cereal; Chemical composition; Yield; Optimization
• ISSN: 0009-0352; 1943-3638
• DOI: 10.1094/CCHEM.2003.80.6.637

Roller milling of hull-less barley generates mill streams with highly variable β-glucan and arabinoxylan (AX) content. For high β-glucan cultivars, yields >20% (whole barley basis) of a fiber-rich fraction (FRF) with β-glucan contents >15% can be readily obtained with a simple short mill flow. Hull-less barley cultivars with high β-glucan content require higher power consumption during roller milling than normal β-glucan barley. Recovery of flour from high β-glucan cultivars was greatly expedited by impact passages after grinding, particularly after reduction roll passages. Pearling before roller milling reduces flour yield and FRF yield on a whole unpearled barley basis, but flour brightness is improved and concentration of β-glucan in fiber-rich fractions increases. Pearling by-products are rich in AX. Pearling to 15-20% is the best compromise between flour and FRF yield and flour brightness and pearling by-products AX content. Increasing conditioning moisture from 12.5 to 14.5% strongly improved flour brightness with only a moderate loss of flour yield on a whole unpearled barley basis. As moisture content was increased to 16.5%, flour yield declined without a compensating improvement in brightness, but the yield of fiber-rich fraction continued to increase and concentration of β-glucan in FRF also increased.