Properties of field-sprouted sorghum and its performance in ethanol production

Abstract The objective of this research was to investigate physicochemical and biochemical characteristics of field-sprouted grain sorghum and its fermentation performance in ethanol production. Five field-sprouted grain sorghum varieties, which received abnormally high rainfall during harvest, were used in this study. Enzyme activities, microstructure, flour pasting properties, kernel hardness, kernel weight, kernel size, flour size and particle distribution of field-sprouted grain sorghum were analyzed. The effect of germination (i.e., sprouting) on conversion of grain sorghum to ethanol was determined by using a laboratory dry-grind ethanol fermentation procedure. Sprouted sorghum had increased α-amylase activity; degraded starch granules and endosperm cell walls; decreased kernel hardness, kernel weight, kernel size, and particle size; and decreased pasting temperature and peak and final viscosities compared with non-sprouted grain sorghum. The major finding is that the time required for sprouted sorghum to complete fermentation was only about half that of non-sprouted sorghum. Also, ethanol yield from sprouted sorghum was higher (416–423 L/ton) than that from non-sprouted sorghum (409 L/ton) on a 14% moisture basis.

[1]  Charles W. Bamforth,et al.  Scientific principles of malting and brewing , 2006 .

[2]  G. S. Bains,et al.  Malting of corn: effect of variety, germination, gibberellic acid, and alkali pretreatments , 1984 .

[3]  L. Rooney,et al.  Malting characteristics of sorghum cultivars , 1995 .

[4]  J. Rowe,et al.  Germination temperature and time affect in vitro fermentability of sorghum grain , 2006 .

[5]  H. Gruppen,et al.  Effects of germination on the activities of amylases and phenolic enzymes in sorghum varieties grouped according to food end-use properties , 2006 .

[6]  António S. Barros,et al.  Protein profile and malt activity during sorghum germination , 2008 .

[7]  S. Adewusi,et al.  Effect of Cultivar, Steeping, and Malting on Tannin, Total Polyphenol, and Cyanide Content of Nigerian Sorghum , 1989 .

[8]  P. Bechtel,et al.  Diastatic Power and α-Amylase Activity in Millet, Sorghum, and Barley Grains and Malts , 1998 .

[9]  O. K. Chung,et al.  Evaluation of the Single Kernel Characterization System (SKCS) for Measurement of Sorghum Grain Attributes , 2006 .

[10]  Jürg M. Blumenthal,et al.  Designing sorghum as a dedicated bioenergy feedstock , 2007 .

[11]  J. Pierce.  THE MARGARET JONES MEMORIAL LECTURE AMINO ACIDS IN MALTING AND BREWING , 1982 .

[12]  A. C. Ogbonna,et al.  Purification and some properties of a cysteine proteinase from sorghum malt variety SK5912 , 2004 .

[13]  G. H. Palmer.  Enzymic degradation of the endosperm cell walls of germinated sorghum , 1991, World journal of microbiology & biotechnology.

[14]  Subramanian,et al.  Amylase Activity and Sprout Damage in Sorghum (Sorghum bicolor L. Moench) , 1984 .

[15]  Andrew D. Jones,et al.  Supporting Online Material for: Ethanol Can Contribute To Energy and Environmental Goals , 2006 .

[16]  R. Agu,et al.  ENZYMIC BREAKDOWN OF ENDOSPERM PROTEINS OF SORGHUM AT DIFFERENT MALTING TEMPERATURES , 1996 .

[17]  D. Evans,et al.  INFLUENCE OF CULTIVAR AND GERMINATION CONDITIONS ON PROTEOLYTIC ACTIVITIES IN SORGHUM MALT , 1990 .

[18]  P. Berjak,et al.  Determination of Improved Steeping Conditions for Sorghum Malting , 1997 .

[19]  R. Moss.  An autoradiographic technique for the location of conditioning water in wheat at the cellular level , 1977 .

[20]  J. Pierce.  HORACE BROWN MEMORIAL LECTURE THE ROLE OF NITROGEN IN BREWING , 1987 .

[21]  C. Ratnavathi,et al.  Effect of different durations of steeping and malting on the production of alpha-amylase in sorghum , 1991 .

[22]  Donghai Wang,et al.  Germination-Improved Ethanol Fermentation Performance of High-Tannin Sorghum in a Laboratory Dry-Grind Process , 2009 .

[23]  D. S. Murty,et al.  Chemical changes and diastatic activity in grains of sorghum (Sorghum bicolor) cultivars during germination , 1992 .

[24]  J. Dufour,et al.  Sorghum Malts for the Production of a Lager Beer , 1992 .

[25]  E. Arendt,et al.  Fundamental study on protein changes taking place during malting of oats , 2009 .

[26]  A. C. Ogbonna,et al.  Protein modification in malting sorghum , 2003 .

[27]  Donghai Wang,et al.  Impact of mashing on sorghum proteins and its relationship to ethanol fermentation. , 2008, Journal of agricultural and food chemistry.

[28]  D. R. Shelton,et al.  Relationship of Sorghum kernel size to physiochemical, milling, pasting, and cooking properties , 2002 .

[29]  E. E. Babiker,et al.  Changes in chemical composition, grain malting, starch and tannin contents and protein digestibility during germination of sorghum cultivars , 1999 .

[30]  M. Tuinstra,et al.  Grain sorghum is a viable feedstock for ethanol production , 2008, Journal of Industrial Microbiology & Biotechnology.

[31]  C. I. Iwuoha,et al.  Effects of steeping condition and germination time on the alpha-amylase activity, phenolics content and malting loss of Nigerian local red and hybrid short Kaura sorghum malts , 1997 .

[32]  Ronald L. Madl,et al.  Factors impacting ethanol production from grain sorghum in the dry-grind process. , 2007 .

[33]  John R. N. Taylor,et al.  Protein Body Degradation in the Starchy Endosperm of Germinating Sorghum , 1985 .

[34]  Mike E Tumbleson,et al.  Effects of ground corn particle size on ethanol yield and thin stillage soluble solids , 2007 .

[35]  John R. N. Taylor.  Effect of malting on the protein and free amino nitrogen composition of sorghum , 1983 .

[36]  L. Rao,et al.  Utilization of damaged sorghum and rice grains for ethanol production by simultaneous saccharification and fermentation , 1999 .

[37]  W. Horwitz.  Official Methods of Analysis , 1980 .

[38]  S. Serna-Saldívar,et al.  Effect of protease treatment before hydrolysis with α-amylase on the rate of starch and protein hydrolysis of maize, whole sorghum, and decorticated sorghum. , 2007 .

[39]  L. Rooney,et al.  Effect of Chemical Treatments on Polyphenols and Malt Quality in Sorghum , 2000 .

[40]  Donghai Wang,et al.  Effects of amylose, corn protein, and corn fiber contents on production of ethanol from starch-rich media. , 2006 .

[41]  L. Beuchat,et al.  Nutritional improvement of cereals by sprouting. , 1989, Critical reviews in food science and nutrition.