Granular starch hydrolysis of babassu agroindustrial residue: A bioprocess within the context of biorefinery

• Published in: Fuel (Guildford) Vol. 124; pp. 41 - 48
• Main Authors: Cinelli, Bernardo A., López, Jimmy A., Castilho, Leda R., Freire, Denise M.G., Castro, Aline M.
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 15.05.2014; Elsevier
• Subjects: Applied sciences; Byproducts; Cold hydrolysis; Energy; Energy. Thermal use of fuels; Enzyme production; Enzymes; Ethanol; Ethyl alcohol; Exact sciences and technology; Flour; Fuels; Productivity; Refining; Simultaneous saccharification and fermentation (SSF); Solid-state fermentation; Starches; Simultaneous saccharification and fermentation (SSF); Solid-state fermentation; Cold hydrolysis; Ethanol; Enzyme production; Hydrolysis; Starch; Enzyme; Saccharification; Fermentation
• ISSN: 0016-2361; 1873-7153
• DOI: 10.1016/j.fuel.2014.01.076

•Babassu is an oil fruit used for diverse chemical applications in Brazil, including biodiesel.•On-site multienzyme preparation generated a hydrolysate rich in carbon and nitrogen sources.•Ethanol production efficiency from babassu flour was up to 83% and concentration was up to 59g/L.•Ethanol production via simultaneous saccharification and fermentation of corn flour was 78g/L. The conversion of renewable feedstocks into a range of commercial products and energy is the principle underlying the concept of biorefinery. In this work, two agroindustrial by-products from babassu were used as unconventional biomasses to develop a sustainable process. Babassu cake was used to produce a multienzyme complex, which was able to hydrolyse starch granules and to release free amino nitrogen from babassu flour, yielding a hydrolysate rich in carbon and nitrogen nutrients. To exemplify its possible applications, different strategies for ethanol production by simultaneous saccharification and fermentation (SSF) were investigated and that comprising a 4-h hydrolysis step at 50°C followed by 44h of SSF at 32°C showed the most promising results (53.6g/L ethanol, 83% efficiency of starch into ethanol and productivity of 1.12g/(Lh)). On-site enzymes promoted better results than a commercial enzyme product (110.9±6.6g/L versus 74.5±1.8g/L glucose releases, respectively), and showed high efficiency and productivity also on corn flour, either similar or superior to those reported for the industrial-scale dry-grind process.