Effects of Amylose, Corn Protein, and Corn Fiber Contents on Production of Ethanol from Starch‐Rich Media

Abstract

Cereal Chem. 83(5):569-575The effects of amylose, protein, and fiber contents on ethanol yields were evaluated using artificially formulated media made from commercial corn starches with different contents of amylose, corn protein, and corn fiber, as well as media made from different cereal sources including corn, sorghum, and wheat with different amylose contents. Second-order response-surface regression models were used to study the effects and interactions of amylose, protein, and fiber contents on ethanol yield and conversion efficiency. The results showed that the amylose content of starches had a significant (P < 0.001) effect on ethanol conversion efficiency. No significant effect of protein content on ethanol production was observed. Fiber did not show a significant effect on ethanol fermentation either. Conversion efficiencies increased as the amylose content decreased, especially when the amylose content was >35%. The reduced quadratic model fits the conversion efficiency data better than the full quadratic model does. Fermentation tests on mashes made from corn, sorghum, and wheat samples with different amylose contents confirmed the adverse effect of amylose content on fermentation efficiency. Hightemperature cooking with agitation significantly increased the conversion efficiencies on mashes made from high-amylose (35-70%) ground corn and starches. A cooking temperature of ≥160°C was needed on highamylose corn and starches to obtain a conversion efficiency equal to that of normal corn and starch.

Agronomic and Kernel Compositional Traits of Blue Maize Landraces from the Southwestern United States

“…Protein and oil values of landraces thus would appear to be higher than those reported for Corn Belt hybrids in multiple studies (Watson, 2003;Belyea et al, 2004;Dudley et al, 2007;Jaradat and Goldstein, 2013) and quality protein maize hybrids (Zarkadas et al, 2000). The crude fiber and ash content were reported to be lower in blue maize compared to yellow dent maize (Wu et al, 2006). In comparison with blue maize, commercial hybrids and modern varieties were reported to be higher in starch (Ridley et al, 2002;Scott and Blanco, 2009), which is consistent with the intense selection for higher grain yield in commercial hybrids.…”

Bio-Ethanol Production from Non-Food Parts of Cassava (Manihot esculenta Crantz)

“…The presence of ash and lipids negatively affects the utilization of sugar, which consequently influences the fermentation efficiency of different feedstocks (Wu et al 2006). These compounds appear to be important in determining the pH (positive correlation between pH and lipid contents) and conductivity of ethanol (positive correlations between ash and conductivity), thus having an impact on yeast growth regimes in the fermentation broth (Klinke et al 2004).…”

Opportunities and roadblocks in utilizing forages and small grains for liquid fuels

“…Wu et al [112], observed higher eYciency of ethanol production from waxy wheat as compared to that of normal wheat, corn of various amylose contents, and waxy and non-waxy sorghum.…”