Urea addition during hydrolysis for increased ethanol yield from white sweet potato: a promising strategy

Abstract Bioethanol is mainly produced from corn worldwide, but many countries face challenges in producing sufficient corn for this purpose. White sweet potato (Ipomoea batatas Linneaus) has a lower nutritional value and less carotene pigment compared to other sweet potatoes, which may make it less desirable as a food source in some regions. However, the affordability of white sweet potato could make it an attractive option for bioethanol production in areas where corn is not readily available. This study investigated the use of white sweet potatoes powder (40 mesh sieve) as a feedstock for ethanol production using Saccharomyces cerevisiae yeast. Optimization of the fermentation process was carried out using response surface methodology (RSM). Results showed that an ethanol yield of 18% could be achieved by applying pH at 4.5 and urea concentration of 60 mg/L. These findings suggest that the addition of urea during hydrolysis of white sweet potato is a promising alternative method for bioethanol production which contained higher etnaol yield compated to the previous finding that utilized amyloglucosidase enzyme during hydrolysis.