EFFECT OF THE CORN GRAIN STORAGE METHOD ON SACCHARIFICATION AND ETHANOL FERMENTATION FIELD

The chemical conservation was chosen in the study as the method for preserving fresh corn grain for distilleries. Five types of preserved corn samples were prepared. The control (with no additives) and four preserved with the preparation, based on formic and propionic acids (KemiSile 2000 Plus), at different levels. All the samples were stored for two months. Ethanol fermentations of low-temperature-cooked and pressure-cooked corn starch were carried out using commercial distillery yeast. The yeast strain, after starch hydrolysis with two enzymes, was able to produce 86-93% of theoretical ethanol yield from low-temperature-cooked corn. The ethanol production was almost equal to that produced from pressure-cooked corn starch (121 degrees C), which was 87-94% of theoretical ethanol yield. The quality of distillates was also investigated. The most common by-products found were: acetaldehyde, ethyl acetate, propanol, isobutanol and 3-metylo-1-butanol. There were no important differences of spirits chemical composition between low-temperature- cooking and pressure-cooking method as well as between the kind of corn sample.