Table of Contents
Biotechnology Research International
Volume 2014, Article ID 654853, 8 pages
http://dx.doi.org/10.1155/2014/654853
Research Article

Ethanol Production from Extruded Thermoplastic Maize Meal by High Gravity Fermentation with Zymomonas mobilis

1Centro de Biotecnología FEMSA, Tecnológico de Monterrey, Avenida Eugenio Garza Sada 2501 Sur, Col. Tecnológico, 64849 Monterrey, NL, Mexico
2Centro de Investigación y Desarrollo en Ciencias de la Salud/UOIE, Universidad Autónoma de Nuevo León (UANL), Avenida Carlos Canseco s/n con Avenida Gonzalitos, Mitras Centro, 64460 Monterrey, NL, Mexico

Received 26 August 2014; Accepted 25 September 2014; Published 3 November 2014

Academic Editor: Triantafyllos Roukas

Copyright © 2014 Mayeli Peralta-Contreras et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

A comparative study of extruded and ground maize meals as raw materials for the production of regular (12°P) and high gravity (20°P) worts was devised. Extruded water solubility index (WSI) was higher (9.8 percentage units) and crude fat was lower (2.64 percentage units) compared to ground maize. Free-amino nitrogen compounds (FAN), pH, and glucose were evaluated in regular and high gravity worts produced from ground or extruded maize. Extrusion improved glucose content and ethanol yield. In 20°P mashes, extrusion is enhanced by 2.14% initial glucose compared with regular ground mashes. The 12°P and 20°P extruded treatments averaged 12.2% and 8.4% higher ethanol, respectively, compared to the uncooked counterpart. The 20°P worts fermented with Zymomonas mobilis produced 9.56% more ethanol than the 12°P counterpart. The results show that the combination of extrusion and fermentation of 20°P worts improved ethanol yield per kg flour until 20.93%. This pretreatment stimulates Z. mobilis fermentation efficiency.