**1.1 Substrates for ethanol production using SSF process**

### *1.1.1 Corn*

According to Miranowski [13], corn is the most viable feedstock for ethanol production. The main factors are high yield, broad geographical cultivation range and available at cheaper cost. Annual production of corn biomass is about 300 × 106 tons (dry basis), about 40% of which are residues which is suitable for ethanol production. Extremely efficient systems are already in place for corn production from seed at very low cost. In evaluating the potential of corn (and any other food crop) for the production of energy, the moral issue of food vs. fuel must be considered. Approximately 66% of the grain produced consumed as food. The proportion of grain that are unsuitable for food production is about 5% of the annual grain production and it is suitable for alcohol production. In many countries corn is used as a raw material. The suitability of corn for ethanol production using SSF process depends on the contents of starch. A high content of horny endosperm leads to problems in ethanol production using SSF processes. The starch isolated from horny endosperm is difficult to gelatinize, and has low swelling, swelling value, and α-amylase digestibility is very less when compared to floury endosperm. Pretreatment of horny endosperm is difficult and requires more enzyme concentration.

*Simultaneous Saccharification and Fermentation and Factors Influencing Ethanol Production… DOI: http://dx.doi.org/10.5772/intechopen.86480*
