Integration of Corn and Cane for Ethanol Production: Effects of Lactobacilli Contamination on Fermentative Parameters and Use of Ionizing Radiation Treatment for Disinfection

Abstract

Recently, in Brazil, corn ethanol industries are being installed and the integration with sugar/energy-cane has been proposed, using bagasse for cogeneration and the juice to dilute the corn. However, this integration may have some limitations, such as the quality of the cane juice and potential contamination by microorganisms brought with the cane from the field. In this article, we first tested the effects of mixing energy cane juice with corn on fermentative parameters. We also assessed the effects of Lactobacilli. contamination on organic acids produced during the fermentation and fermentation parameters and proposed the use of ionizing radiation to replace antibiotics as a disinfection control method. Our results showed that mixing energy cane juice with corn does not have any negative effect on fermentation parameters, including ethanol production. The contamination with Lactobacilli. considerably increased the production of acetic, lactic, and succinic acid, reducing the pH and ethanol content from 89.2 g L−1 in the sterilized treatment to 72.9 g L−1 in the contaminated treatment. Therefore, for the integration between corn and cane to be applied on an industrial scale, it is essential to have effective disinfection before fermentation. Ionizing radiation (20 kGy) virtually disinfected the wort, showing itself to be a promising technology; however, an economic viability study for adopting it in the industry should be carried out.