USA: Barley could be an alternative source of grain for ethanol producers

Barley could be an alternative source of grain for ethanol producers who can't afford to ship corn from the Midwest to their processing plants in the eastern and western states, Agricultural Research Service (ARS) scientists who are studying different types of barley and processing methods for producing ethanol from this grain crop, revealed on July 12.

Barley grows well in eastern and western states, according to researchers at the ARS Eastern Regional Research Center (ERRC) in Wyndmoor, Pa. But low starch content in most barley varieties--50-55 percent compared to corn's 72 percent--results in lower ethanol yield.

So the scientists are helping to create new barley varieties with higher starch content to solve this problem. They're looking at malt, hulled and hull-less barley suitable for growers in various parts of the country.

Barley hulls are very abrasive and cause expensive wear and tear on grain handling and milling equipment. Removing the hull and other nonstarch components of the kernel before fermentation for ethanol would greatly improve the ethanol process.

Along with having lower starch content than corn, barley also contains a polysaccharide, called beta-glucan, which makes barley mash too sticky to mix, ferment and distill economically, according to Kevin Hicks, research leader of ERRC's Crop Conversion Science and Engineering Research Unit.

ARS researchers are developing new milling processes to remove beta-glucans before fermentation. They're also studying methods to separate low-starch barley kernels into a starch-enriched stream for efficient ethanol production.

Among the barley varieties under study, several Virginia hull-less lines look promising. Hull-less varieties lose their hulls during harvesting, have higher starch and protein, and are lower in fiber than hulled varieties.

13 July, 2005