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Title: Near-Infrared analysis of ground barley for use as a feedstock for fuel ethanol production

Author
item Sohn, Mi Ryeong
item Himmelsbach, David
item Barton Ii, Franklin
item GRIFFEY, CARL - USDA
item BROOKS, WYNSE - USDA
item Hicks, Kevin

Submitted to: Journal of Applied Spectroscopy
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/16/2007
Publication Date: 11/1/2007
Citation: Sohn, M., Himmelsbach, D.S., Barton Ii, F.E., Griffey, C.A., Brooks, W., Hicks, K.B. 2007. Near-Infrared analysis of ground barley for use as a feedstock for fuel ethanol production. Journal of Applied Spectroscopy. 61 (11). p. 1178-1183.

Interpretive Summary: Higher energy costs have become a reality for everyone worldwide and development of renewable fuels has been emphasized. Corn is currently the main feedstock for ethanol in the US. However, the amount of fuel ethanol production from corn alone will not be enough to cover the US transportation fuel needs. Obviously, other feedstocks are needed. Recently there has been growing interest in using barley as a feedstock for fuel ethanol production. Due to barley’s physical and chemical properties-an abrasive hull, low starch content, high fiber content and high viscosity, barley has not been considered a viable feedstock in the US. Recently, a new hull-less variety of barley has been developed and released. The high starch and protein content of the new barley makes it a potential useful variety for fuel ethanol production. Rapid determination of components in barley is important to estimate ethanol yield or to evaluate co-product quality. The aim of this study was to investigate the possibility of using near-infrared spectroscopy to evaluate ground barley as a feedstock for fuel ethanol production. For robust calibration, three types of barley grown over a three-year period were collected and the new variety barley that was specially bred for potential use in ethanol production was added to the sample set to test. In addition, two NIR spectrometers with different resolutions were used to develop calibration models and compared the accuracy of the model. The research result will give an interest to a broad audience who work in the field of bio-fuel production and work in the field of algorithm development using spectroscopic data.

Technical Abstract: Recently there has been growing interest in using barley as a feedstock for fuel ethanol in the United States. The objective of this study was to explore the potential of near-infrared spectroscopy for determining the compositional quality properties of barley and to compare the prediction accuracy between calibration models obtained using a Fourier transform near infrared system (FT-NIR) and a dispersive NIR system. The total sample set contained 206 samples of three types of barley: hull-less, malt and hulled varieties, which were grown at various locations in the eastern U.S. from 2002 to 2005 years. A new hull-less barley variety, Doyce, which was specially bred for potential use in ethanol production, was included in the sample set. One hundred thirty-eight barley samples were used for calibration and sixty-eight for validation. Ground barley samples were scanned on both a FT-NIR spectrometer (10,000 to 4,000 cm-1 at 4 cm-1 resolution) and a dispersive NIR spectrometer (1100 to 2498 nm at 10 nm resolution), respectively. Six grain components: moisture, starch, '-glucan, protein, oil, and ash content were analysed as parameters of barley quality. Principal component analysis showed that barley samples could be classified by their types: hull-less, malt and hulled. Partial least square regression indicated that both FT-NIR and dispersive NIR spectroscopy have a potential to determine quality properties of barley with an acceptable accuracy, except for '-glucan content. There was no predictive advantage in using a high resolution FT-NIR instrument over a dispersive system for most components of barley.