EVOLUTIONARY ENZYMES AND SEPARATION PROCESSES FOR IMPROVED BIOREFINING OF CROPS AND RESIDUES
Location: Bioproduct Chemistry and Engineering Research
Title: NATIVE OR RAW STARCH DIGESTION
Submitted to: Journal of Agricultural and Food Chemistry
Publication Type: Review Article
Publication Acceptance Date: November 11, 2005
Publication Date: December 22, 2005
Citation: Robertson, G.H., Wong, D., Lee, C.C., Wagschal, K.C., Smith, M.R., Orts, W.J. 2006. Native or raw starch digestion: A Key step in energy efficient biorefining of grain. Journal of Agricultural and Food Chemistry, 54:353-65.
Improved molecular disassembly and depolymerization of grain starch to glucose is key to reducing energy use in the bioconversion of glucose to chemicals, ingredients, and fuels. In fuel ethanol production these biorefining steps use 10- 20% of the energy content of the fuel ethanol. The need to minimize energy use and to raise the net yield of energy can be met by replacing high-temperature, liquid-phase, enzymatic digestion with low temperature, solid-phase, enzymatic digestion. Also called cold hydrolysis, the approach is a step toward a "green" method for the production of fuel ethanol. There has been substantial prior and increased recent interest in this approach that is presented in this first review of the subject. We include incentives, developmental research, fundamental factors of raw starch digestion, and novel approaches in enzymology and processing. The discussion draws on resources found in enzymology, engineering, plant physiology, cereal chemistry, and kinetics.