Development of baking yeast from Nigerian palm-wine yeasts

Two local strains of Saccharomyces cerevisiae, Nk, and Nk₂, showed leavening activities of 103% and 102% of that of a commercial yeast strain on wheat flour and of 114% and 113% on composite dough with 40% (w/v) maize substitution. Yeast fusion products Nk/Ng, Nk/Nk₁ and Nk/Nk₂ showed activities of 104% to 113% on wheat flour and 111% to 131% on the composite dough. These advantages were maintained in the yeasts' baking properties and organoleptic qualities. The fusion products also showed enhanced osmotic tolerance, as indicated by good growth in 3%, 6% and 10% (w/v) NaCl and 50% (w/v) glucose. Viability of the fusion products, preserved by drying at 30 to 35°C, dropped to between 62% and 72% after 3 months.A.O. Ejiofor was and N. Okafor and E.N. Ugwueze are with the Department of Applied Microbiology and Brewing, Nnamdi Azikiwe University, P.M.B. 5025, Awka, Nigeria. A.J. Ejiofor is now with the Abteilung Biovertahrenstechnik, Gesellschaft für Biotechnologische Forschung, Mascheroder Weg 1, D-38124 Braunschweig, Germany