ARS | Publication request: MILLING ALTERNATIVES OF BARLEY TO PRODUCE ETHANOL AND VALUE-ADDED FRACTIONS

Submitted to: Meeting Abstract
Publication Type: Proceedings
Publication Acceptance Date: September 20, 2005
Publication Date: October 20, 2005
Citation: Flores, R.A., Hicks, K.B. 2005. Milling alternatives of barley to produce ethanol and value-added fractions. Proceedings of the 35th United States-Japan Cooperative Program in Natural Resources: Food and Agriculture Panel, pp. 52-57.

Technical Abstract: New varieties are being developed to widen the applications of barley to nontraditional food and non-food value-added applications, such as ethanol production. The objective of this study was to fractionate a new hulless barley variety, Doyce, to produce starch rich fractions using two methods: (a) using an experimental milling system consisting of a roller mill walking flow, and (b) a grain peeling system consisting of a scarifier. The milling walking flow was originally designed for wheat flour and consisted of four breaks for four resulting streams: bran, shorts, reduction flour and break flour. The scarification study was conducted using an electric laboratory seed scarifier with three abrasive surfaces (36, 40, and 50 grit) at different scarification times for a total of twenty-two treatments. In the experimental milling results from the milling walking flow, 50% of the starch in the barley was found in the combination of the reduction and break flours. However, over 50% of the total starch is in the bran and shorts. Further processing of the shorts, perhaps using a bran finisher and/or a bran purifier, might reduce the amount of starch in the shorts, thus increasing the total mass yield of high starch fractions to above 42%. The effect of the different abrasive surfaces on the mass distribution of the fractions processed in the scarifier is not evident during the first 50s but it is obvious at scarification times greater than 50s. The ash content of each fraction follows a linear relationship but in opposed directions. The scarification results indicate that the coarse fraction that represents 70% of the kernel mass has a starch content of 75%; thus, representing an increase of more than 10% starch over the original whole Doyce barley. A combination of scarification with roller milling and the fermentation of the fractions is the next step that we are going to work on to optimize the ethanol production from hulless and hulled barley varieties.