| | In view of the growing interest in using barley fractions as functional food ingredients, this investigation was initiated to evaluate the milling potential of Canadian hulless barley genotypes with variable amylose content. Roller milling of hulless barley generates mill streams with variable starch, ß-glucan and arabinoxylan contents. Hulless barley genotypes with high ß-glucan content require higher power consumption during roller milling than normal ß-glucan barley. Recovery of flour from high ß-glucan genotypes can be expedited by impact passages following grinding, particularly after reduction roll passages. Pearling prior to roller milling reduces flour and fiber-rich fraction (FRF) yields on a whole unpearled barley basis, but flour brightness is improved, and concentration of ß-glucan in FRF increases. Pearling by-products are rich in arabinoxylans. Pearling to 15 to 20% is the best compromise between yield and composition of flour and FRF, flour brightness and pearling by-product arabinoxylan content. Increasing conditioning moisture from 12.5% to 14.5% results in a strong improvement in 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 FRF continued to increase, and concentration of ß-glucan in the FRF also increased. The FRF has obvious potential as a functional food ingredient and can be successfully incorporated into products such as noodles and bread.
M.S. Izydorczyk, J.E. Dexter, K. Preston, and D.W. Hatcher
Grain Research Laboratory, Canadian Grain Commission, Winnipeg, MB R3C 3G8
Presented at the 3rd Canadian Barley Symposium, June 19-20, 2003 |
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