African Journal of Biotechnology Vol. 4 (11), pp. 1290-1296, November 2005          
ISSN 1684–5315 © 2005 Academic Journals

Full Length Research Paper

The alcoholic fermentative efficiency of indigenous yeast strains of different origin on orange juice

Wahab. O. Okunowo*, Rufus. O. Okotore and Akinniyi. A Osuntoki

Department of Biochemistry, College of Medicine, University of Lagos. P.M.B. 12003. Lagos. Nigeria.

*Corresponding author. E-mail: modelprof@yahoo.com.

Accepted 24 June, 2005

The alcoholic fermentative ability of yeast strains; Saccharomyces cerevisiae (isolated from yam), S. cerevisiae (from sugarcane molasses), S. carlsbergensis (from sugarcane molasses) and S. cerevisiae var. ellipsoideus (from orange juice) were examined on orange juice (Citrus sinensis). The quality of the wine produced on the basis of the acidity, ash content, vitamin C and the alcohol content were assayed. The fermentation efficiency varied between 48.05% with S. cerevisiae var. ellipsoideus and 99.46% with S. carlsbergensis. The highest ethanol concentration, yield and productivity were 6.80 ± 0.07% (w/v), 0.46 gg^-1 and 0.57g l^-1h^-1, respectively. The rate of sugar utilization was least, (2.76 g/day) with S. carlsbergensis and highest (3.07 g/day) with S. cerevisiae from yam. The total alcohol produced was least (3.19 ± 0.21%, w/v) with S. cerevisiae var. ellipsoideus and highest (6.80 ± 0.07%, w/v) with S. carlsbergensis. The optimum pH ranged between 3.81 for S. cerevisiae var. ellipsoideus and 3.71 for S. cerevisiae (from yam). The Vitamin C level was highest (9.02 mg/100 g) with S. cerevisiae var. ellipsoideus and lowest (6.65 mg/100 g) with S. carlsbergensis.

Key words: Saccharomyces, yeast strains, fermentation, orange wine.