Production of Ethanol from Ipomoea batatas using Saccharomyces cerevisiae

A study was carried out on yeast fermentation of sweet potato (Ipomoea batatas) using baker’s yeast (Sacchromyces cerevisiae). The fermented sugar syrup (broth) was analyzed for yeast growth, alcohol content, reducing sugar, pH, soluble solids, volatile acids and total acidity using standard protocols. Yeast growth was also monitored. Results showed that pH values decreased with increased total acidity with concomitant increase in yeast growth (biomass) and alcohol contents of the fermenting sugar syrup. There were decreases in soluble solid contents, refractive indices of the fermenting medium. The reducing sugar in the Ipomoea batatas was lowest after 48 h of saccharification using Sacchromyces cerevisiae.The value recorded was 132 to 87 mg/100ml. Volatile acids (as acetic acids), increased with alcoholic fermentation. Fermentation of sugar syrup from Ipomoea batatas is associated with physical and chemical changes that occur in other form of fermentation alongside increased in biomass. The fermented Ipomoea batatas yielded ethanol contents of 11.5 to 53.0% (v/v).