Full Length Research Paper

Physical, chemical and microbiological changes in alcoholic fermentation of sugar syrup from cassava flour

F. C. K. Ocloo¹* and G. S. Ayernor²

¹Biotechnology and Nuclear Agriculture Research Institute, Ghana Atomic Energy Commission, P.O. Box LG 80, Legon, Ghana.

²Department of Nutrition and Food Science, University of Ghana, Legon, Ghana.

*Corresponding author. E-mail: f.ocloo@bnari.org or ocloofid@hotmail.com. Tel: 233-244467195.

Accepted 4 January, 2008

Changes in alcoholic fermentation of sugar syrup produced from cassava flour with Saccharomyces cereviseae (baker’s yeast) were investigated. Cassava flour paste was hydrolysed using rice malt to produce hydrolysate (sugar syrup), which was fermented at 28 – 30°C for 1, 2, 3, 4 and 5 days. The fermented sugar syrup was analysed for alcohol content, reducing sugars, specific gravity, soluble solids, pH, volatile acids and total acidity using standard analytical methods. 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. Volatile acids (as acetic acids), increased with alcoholic fermentation. Fermentation of sugar syrup from cassava flour is associated with physical and chemical changes that occur in other form of fermentation alongside increased in biomass.

Key words: Fermentation, biomass, alcohol, sugar syrup, Saccharomyces cereviseae.