Effect of corn grain variety on the bioethanol production efficiency

• 258 different corn varieties were used in ethanol fermentation.
• The hybrids of corn were created with four male parents.
• Higher starch content caused lower efficiency of starch saccharification.
• Ethanol productivity depended on variety and starch content in corn grains.
• Corn hybrids with S80660A male parents have the biggest impact on ethanol efficiency.

The impact of corn grain variety on the ethanol production effectiveness was determined. The screening of 258 various corn samples were done. The endosperm of recognized 258 types of corn was semi flint as a consequence of crossing between female parent with dent type seeds and male parent with flint type seeds. The tested cultivars fall into two groups, ie. 133 belong to single cross (SC) and 125 belong to three-way cross (TC) hybrids. These hybrids of corn were created with four male parents: 96 with S61328, 61 with S80660A, 20 with S07787A and 8 with S09347. The corn samples were mashed and fermented with distillery yeast Saccharomyces cerevisiae which produced ethanol from corn mashes yielding maximum 81.33% of the theoretical value. It was noted that the corn samples with higher starch content had lower efficiency of starch saccharification (−0.35, p < 0.05). This fact generates negative correlation between variables ethanol (L/100 kg starch) and starch content (−0.43, p < 0.05). The highest level of reducing sugars in grains led to higher productivity of ethanol. The comparisons in groups generated with multivariate exploratory techniques (cluster analysis, k-means clustering, PCA) showed that it is possible to distinguish a statistically different cluster with the highest ethanol yield (35.6 L of ethanol per 100 kg grains). Moreover, the PCA analysis showed that hybrids of corn with S80660A male parent have the biggest impact on efficiency of ethanol. The presented results clearly prove that not only starch content in corn grains determine the ethanol productivity.